Friends,
Tom McKenna did a good article on “a new breed of bandsaws” a few years ago. It was about bandsaws for re-sawing. One of the parameters he tested was whether the two wheels were co-planar. I believe only one saw came that way. But the Powermatic’s wheels were 1/8″ out of “co-planar”. He said that this could not be fixed because the arbor was so short that there was not enough room to add shims. I wrote and asked him what he did about it, and he said there was nothing he could do about it. Yet he liked the machine and recommended it.
My questions are:
should you be able to make the wheels coplanar on a bandsaw?
How far out of co-planar is still OK?
If you buy a new bandsaw and the wheels cannot be made co-planar, as in the case of the Powermatic that FWW tested, what should the manufacturer do for you? Is this something that can be fixed with a new part, or is it a showstopper?
Thank you.
Mel
Measure your output in smiles per board foot.
Replies
Mel:
I'm not a mechanical engineer. But, if you pick a single attribute of an item of machinery and ask how important it is that it meets a certain specification or level of accuracy, then I haven't a clue and I suspect that 99% of our Knotizens don't either.
It sounds as if they should be co-planar but I am only concerned with the product's performance as an integrated system. It sounds as if the saw performed well enough so maybe we don't care about co-planarness within a certain tolerance.
Here's an analogy: Let's say you are my friend and vice-versa. Let's also say that you suddenly announce that you have a boil and your arse. Are you still my friend? Does it make a difference? Should it make a difference? Can you perform all the rights and obligations of friendship unhindered by said boil?
It sounds as if the Powematic has the equivalent of a boil on its arse. Maybe that will upset you!
Regards,
Hastings
PS Knots appears to prefer the english spelling of ###
Edited 10/6/2009 9:24 am ET by Hastings
Hastings,Exactly where the center point is where in that trusty blade doth lie is still a subjective thing.
It may be an area of great "fiddle" here on Knots what with the micro bevel on microbevel plane enthusiasts and all, or among those that come from a machinist background (with their higher degrees of calibration). It may just be a Knots talking point when times are thin.I think for the most part such articles are intended for those that have a real bad unit or those that just what to hot rod the unit. Both good areas for an article but I wonder just how much of the CP adjustments show up in real life.
Kind of like chasing dust on a table saw top -- no matter what, you ain't never going to git it all.I worked for years with a saw that was not CP and it did a fine job with resawing , etc. It wasn't way out but it wasn't in either. One day I added a aluminum can shim and it was perfect. No change on the cut though. I suppose it depends on the machine. If I had spent today's prices on a machine that wasn't what most people think is the minimum acceptable I think would might seek recourse or return. The PM in the article probably worked just fine, just out of kilter a wee bit.I think your right, sometimes a bit of boiled arse doesn't hurt nuttin.
(Of course it do depend on if you be a sittin or if you be a standin)Watching glue dry on the coastBB
Hastings,
You bring up a very interesting point. Which is the one I brought up. Just how close to co-planar should the two wheels be. I am hoping to get a response from someone who knows. Maybe John White. That would be good. If the wheels don't need to be co-planar, then, how much can they be off, and have the system perform "just fine"? I sold my previous bandsaw, and am looking at alternatives for replacing it. I didn't ask "Which bandsaw should I buy?" Rather, I am trying to understand the limits of unacceptability, and what the manufacturer can be expected to do if they exceed the limits. Maybe we will all learn something about this. Thanks,
MelMeasure your output in smiles per board foot.
Mel; That is a very good question, I'm interested to see what kind of replies on this topic you get. Also in that article Thomas talks about misaligned guide post, he speaks of serous misalignment, what would be considered tolerable and what would be as you say a showstopper. Just my two cents worth. Hope your having a good day and good luck with your new saw endeavor.
Mike
Mike,
Thank you for asking that question. I am sure we will get good answers.
I like articles which give me information I can deal with. If the article describes eight bandsaws, and gives the "out of coplanar" measurement in thousandths of an inch for each, I don't know what to do with that info. Are all of them OK? Are none of them OK, as far as real work is concerned. How far must it be different from 0 before I have to worry about it?
Please stay with the thread, and we'll get your question answered too. I want to know the answer to your question too.
THanks for writing.
MelMeasure your output in smiles per board foot.
Mike,My guides are bearings which are attached off center on a piece of hex bar. With a lot of fiddling I was able to get the blade to blade to run reasonably straight, but not quite perfect. One I pulled off the table and had a close look and discovered this "undocumented feature".
I removed and reinstalled the guides so they all properly oriented. Don
Don:
Thanks for the reply, just curious what is the "undocumented feature" you speak of? My guide post on my 14" Delta with a riser block is very close but not perfect, I didn't think on a smaller saw you where able to make any adjustments for the travel of the guide post. For me it is not a big issue if I move the guides up close to the top for some resawing I would have to readjust the top guides. I haven't done very much resawing so like I said for me it is not an issue. As Mel pointed out about the wheels being coplanar they tell you in thousands of an inch as is the same with guide post misalignment which they all seem to have some amount of, so what would be considered to much. Thanks again for your input on this topic.
Mike
"Undocumented feature".
The setup instructions in the manual make no reference to how the elements in the upper and lower guide assemblies should be positioned in the support bracket. It is actually quite good when done right, not so good when not.
Certainly things like guide post alignment get worse with riser kits. The 12" post has a little more flex than the 6".
Don
Yes Don I agree with you that post alignment can get worse with a riser kit as you said also a riser kit is not really factory equipment. When you said in our previous post "Undocumented Feature" I thought maybe you had a way to adjust for the travel of the guide post on your saw. Thanks.
Mike
Mel,
When I got my bandsaw, I didn't know the first thing about them, so I read the books and adjusted them as described, which included making the wheels co-planar. One washer was all it took on my Jet 14". That saw worked very well, until about two months ago, when a blade broke with a tremendous bang. After that it did not track as well, but it was still useable, that is until I tried to make an inlay. The saw just would not hold the tolerances needed, which were plus or minus .005". I finally checked the wheels for co-planarisum (no doubt a new word) and they were off. Removing the washer that had resided there since 1997, has the saw working perfectly again. While I can't explain/figure out what happened, the experience tells me that being co-planar is fairly important.
Rob Millard
http://www.americanfederalperiod.com
Rob,
Very interesting. I am sure you are right that coplanarism is good. But if it is, then why did the Powermatic, whose wheels were out by more than 1/8 inch, work so well that they recommeded the saw, even though the arbor was too short to add washers to make the two wheels coplaner?
Practically speaking, when I buy a new bandsaw, and I test it for coplanarism, what do I do if, like the FWW Powermatic, it can't be fixed with shims? I wan't to get some advice from someone who "knows" so I can ask the company that I buy from the right questions before I make the purchase.
My questions here are not meant for you to answer. I am hoping to get an answer from someone who is a bandsaw expert. My guess is that there is at least one in Knots or on the FWW staff.
Thank you for your insightful comment.
MelMeasure your output in smiles per board foot.
Why not just buy a model that you know can be adjusted?
Old Saw,
sounds like a great idea.
Thank you.
MelMeasure your output in smiles per board foot.
hi rob,
so, your bandsaw went from not co-planer to co-planer back to not co-planer? and it is working just fine? if so, does this not sort of attest to the unimportance of co-planer?
eef
eef,
I must have not worded my posting correctly.
When I first got the saw it was not in alignment. I then shimmed the upper wheel and got the wheels in the same plane. After the blade broke, the wheels shifted (don't ask me how) and were no longer in the same plane, which affected the cut. I removed the shim, which brought the wheels back into alignment and the saw now works perfectly again. All of this tells me, with my particular saw that co-planar wheels do indeed make for a more accurate cut. Having said that, I doubt that for the average cut it would make much difference, but for demanding cuts like resawing or in my case making inlay bandings that extra accuracy is important.
Rob Millardhttp://www.americanfederalperiod.com
i see. thanks.
eef
Mel,
I don't think co-planar is a condition that is that critical to a band saw's performance, although a great deal seems to be made of it in the all the "correct" band saw books. If a machine has a serious misalignment, that's another story, but 1/8" out of co-planar should not matter. Correct adjustment of the tracking setting is so much more influential that as long as the upper and lower wheels are within an acceptable tolerance for co-planar (I wouldn't be surprised if 1/4" is insignificant on a 17" or larger machine) the machine will perform as well as possible.
I always refer people to Michael Fortune's article, "Five Tips for Better Bandsawing," in the Dec 2004 FWW (available here in the archives) as the most useful information ever written on the subject. His no-nonsense advice dispels several often-repeated myths and explains straightforward, non-exotic techniques and blade advice to set up any band saw to do perfect, sweat-free re-sawing.
Rich
Rich,
I like Michael Fortune's article. As I remember, it doesn't say anything about making the wheels coplanar. I don't know if he didn't mention it because it is not important, or because he just assumed that the machine has to be in good shape. I am positive that if the two wheels on a 14" bandsaw are not coplanar by 2", it just won't work. I am positive that if the wheels on a 14" bandsaw are only .0001 off, that it will work just fine. I want know how far out of coplanar the wheels have to be before ACTUAL PERFORMANCE is negatively affected.I work at a Woodcraft store for a about a day a week. Today, I asked my coworkers if they have ever checked their bandsaws to see if the wheels are coplanar. NOT A ONE OF THEM EVER HAD. I asked a number of customers, and most didn't know that the wheels are supposed to be coplanar. I believe that Duginski and Bird said in their books that coplanar is important. THe FWW article on 14" bandsaws for re-sawing gives "out of coplanar" for each bandsaw and mentioned that the Powermatic bandsaw was out by 1/8" and could not be fixed because the arbor is too short to add shims. Yet it performed well in resawing. If it is not important, why did they even bother to mention "coplanar" and make and show measurements? Why to so many woodworking authors push it. I merely want to hear from someone who is a specialist in woodworking tools, especially bandsaws, just how far out of "coplanar" a 14" bandsaw can be and still perform well. Indeed, it may be that the machine can be made to perform well by tilting the wheel more. Does that cause long term damage to the wheel bearings, etc? I will write to John White, and ask his opinion. I am thinking of contacting Powermatic and Delta and see if they let anyone talk to me about this question. I doubt they will, but it is worth trying.Let's see if we can get some expert advice?
Thanks,
MelMeasure your output in smiles per board foot.
John,
I think it is time to get some expert advice on this issue. I have gotten some nice responses from some nice folks, but no one seems to have any real expertise on the issue. Please look at my original post in this thread. I sold my old 14" Rikon bandsaw. It is not the "Delux" model that was tested in Tom McKenna's article on a new breed of 14" bandsaws for re-sawing. I studied that article, and it left me with real questions on what is important in picking a bandsaw. I called him, and he responded to the question I asked, and he was very professional and very knowledgeable. I asked whether the "poor castings" on the 14" Delux Rikon's blade guides were a nit or a showstopper. He explained that it was not only the poor castings but also the entire mechanism which was poorly designed, and that he believes that is a showstopper. I tried to adjust the guide bearings on the 14" Delux Rikon, and I agree fully with him.I asked him about the comment that the Powermatic's wheels being 1/8" out of coplanar. The article said that it couldn't be fixed because the arbor was too short to add shims. I asked him what they did to the machine to get such good performance on resawing. He said they did nothing, because they couldn't.I am considering buying a Powermatic, and am concerned about this. Suppose I get one which is out of tolerance. I have to find out whether the manufacturers have a specification on that parameter, and what they will do if I receive a machine which is out of tolerance. Suppose I get one which is out by 1/8" like FWW did. Will they send me a new one? Will they send someone to replace some parts? Mostly, I wonder how far out of coplanar the wheels must be before performance is negatively affected. How can I get information on this? The info that is out there is contradictory. The Bandsaw books say that you need to make the wheels coplanar, but the FWW article didn't do that and got good performance. Will a bandsaw like FWW's Powermatic, which was 1/8" out, screw up its wheel bearings or anything else, if it is operated like this for a while?Michael Fortune's great FWW article never mentioned "coplanar". I wonder if that means he doesn't think it is important, or if he just assumed that adjustment has been made.You are the most knowledgeable person I know of in Woodworking tools. I figured that if anyone could shed some real light on this, it is you. Thank you. I apologize for the length of this question. I think that the answer to this question would be worth an article in FWW. When a tool review gives real measurements on a parameter, I suggest that it also tell readers what number these measurements should not go beyond for adequate performance. In other words, what do I have to worry about, and what can I ignore in making an intelligent, informed decision.MelMeasure your output in smiles per board foot.
Mel,He doesn't use the term coplanar but says on page 5, par 4, "Much has been made in books and articles about the alignment of the two wheels to each other . . . I have never found this to be a problem. Tracking the blade properly on the upper wheel has always been enough except in the case of a severely damaged bandsaw."Rich
Rich,
Thank you for reminding me that he said that about the two wheels. I wonder if he found that is wasn't a problem because the ones he had were ok, or because it is really not a problem.I have been learning more. Highland Hardware has an interesting article. If the two wheels are not coplanar, then the blade can be centered on the top wheel but will not be centered on the bottom wheel. SO is this a real problem? I don't know. If the blade is forward on the bottom wheel, does that put extra pressure on the wheel bearings? I am not a mechanical engineer. I do believe that a saw which is "in tune" with wheels which are true and balanced and coplanar will run more smoothly, thus giving you a better cut. But that is "theory". Can't wait to hear from John White.
MelMeasure your output in smiles per board foot.
Mel'"I wonder if he found that is wasn't a problem because the ones he had were ok, or because it is really not a problem"Well, maybe I should have included his entire quote and not left out the few words in the ellipsis.He actually said, "Much has been made in books and articles of the alignment of the two wheels to each other. In my shop and in my travels to schools around North America, I have never found this to be a problem. Tracking the blade properly on the upper wheel has always been enough, except in the case of a severely damaged saw."I think it's fair to say he has extensive experience with bandsaws (emphasis on plural).I have no such record. I have set up and used 4 saws since reading his article in 2004 - two 14s an 18 and now my 17" Grizzly. Mindful of his advice, in particular using new, sharp blades (all inexpensive BC Saws' Starrett blades, 1/2" 3 TPI) and setting the tracking to keep the blade centered accurately on the crown of the top tire so that the blade ran parallel to the miter slot - all the saws performed flawlessly when re-sawing and were accurate for fine detail in other work.I never tried to get the wheels to be perfectly co-planar. On 2 saws, it was too hard to determine if they were or were not (14" Grizzly and 18" Laguna). A 14" Delta was close as is my 17" Grizzly.Rich
Rich,
You are very convincing.I wonder why the FWW article on "a new breed of 14" bandsaws" showed the numbers for "out of coplanar", and mentioned that the Powermatic couldn't be fixed. Is it possible that coplanar is not important at all, but very few people know it. One does see it written about. Maybe it has become an "urban legend". I'll have to check on http://www.snopes.com :-)Thank you very much. I appreciate your taking the time to educate me.
MelMeasure your output in smiles per board foot.
My Hammer 4400 bandsaw was 1/8" out of coplanar at delivery. Blade drift was improved by adjustment to nil. This involved removal of the table and using a 6' straight edge which made contact with both wheels at the centre of the rims in a vertical line. The adjustment necessary was miniscule. Was it worth it for the drift improvement? No. Test cuts in 1/4" slices X 12" tall of dry English oak before and after revealed a 1/64" difference over a 2' cut. I wish I hadn't bothered (particularly as I dropped the table onto my little toe)! Its the last time I'll be as anal as that.
Edited 10/10/2009 3:24 pm by DrHWO
DrHWO,You dropped the table from a Hammer 4400 onto your little toe? And you still have a toe?Rich
Not that you would recognize. Just a mushy bag of connective tissue with no toe nail. Accident was 8 months ago and my stomach still churns at the thought. The nurse in the local casualty dept fainted!
With a new saw or a saw that does not track well, I start by making the wheels coplanar. Then I adjust,if needed the top wheel til the blade tracks in the center or at least close to the center of the wheel. If the blade tracks well ,I'm ready to saw and never checked the amount of offset of the wheels. Some saws,maybe less than 1/8" others I know were much more. How much more? didn't care as long as the saw performed as it should. I would not be too concerned with coplanar as it really is just a starting point in my opinion.
mike
Mel,
My thought.
Without a blade, the 2 wheels should be damn close to co planar. If not, then you will have to over compensate to get your tracking correct.
You can probably do this but the blade will ride off the crown on one or possibly both wheels. This can result in the blade doing a back and forth motion as it cuts, almost as if it were on a cam.
With more of the saws being made from structural steel rather than casting, this type of issue should not occur, certainly not accepted.
Don
Don,
I tend to think you are correct.
Others here are saying just the opposite, that it doesn't make any difference (up to a point). But remember the Powermatic bandsaw in the FWW test was off by 1/8" inch, and because the arbor was totally filled up, there was no way to add shims, so they left it the way it was, and it did some nice cuts. BUT maybe it wouldn't last very long.That is why I am waiting for an answer from John White, the head of the FWW shop. When it comes to woodworking tools, he has the experience.Let's see what he has to say.
Thanks for writing.
Mel
Thanks,
MelMeasure your output in smiles per board foot.
My next thought is it isn't an issue for most because the factory QA/QC catches any machines that are outside of their tolerance. The Powermatic machine tested in the review may have been one that got through the cracks. Maybe +/- 1/8" is within Powermatic's normal tolerance. If that detail is important, then you need to find out what each manufacturer deems to be within tolerance and use that in your selection criteria.
I have a King Industrial 14" with the King 6"riser block. I just went out an checked it. With no tension of the top wheel, the wheels are in line. When I apply tension to the 1/2" 3TPI blade and adjust the tracking so there is no drift, the bottom edge of the top wheel is in by about 1/16".
I pushed a 4" piece of padauk though and got a nice piece of 1/16" veneer.
I guess it really does not matter as long as the tracking can be adjusted but you would have to be careful if you wanted to cut tenons. If the top wheel is +/- 1//8" then the blade will not be 90 degrees in that axis. Not much, but then we keep seeing measurements +/- 0.001" in some of the reviews.
What can you live with?Don
The wheels on a bandsaw should be coplaner to perform at an optimum level.I would not knowingly buy a bandsaw that the wheels were not within the manufacturers design tolerance for being coplaner. Why anyone would consider doing so is a mystery to me. The bandsaw manufacturer should be able to tell you what their engineering design tolerance is for the bandsaw wheels being coplaner after assembly. There is always a tolerance range (specification) that machines are designed and built to and designed to operate within. Exceeding that tolerance would require maintenance and correction to bring the machine wheels back within the design tolerance for optimal operation. Operating the machine out of tolerance will put adverse stress on components of the machine i.e. bearings, the band saw blade, etc., and possibly create an unsafe situation for the operator.
Don,
You make a case for coplanar being necessary. Others in this thread make a case that it doesn't matter. It performed well even though its wheels were over 1/8" from coplanar. How do you account for that. Do you think it will work for a while and then break because of the pressures that build up from the wheels not being in the same plane? Obviously you can get good performance even though the wheels are not coplanar. FWW would not lie.Here is a quote from the FWW review on the Powermatic 14" bandsaw. "The Powermatic comes loaded with accessories and has plenty of mass and power. It ranked high for performance among its cast-iron brethren, but the wheels were misaligned by more than 1/8 in. on the machine we tested."Michael Fortune's article on tuning a bandsaw in FWW states:"Much has been made in books and articles
of the alignment of the two wheels to
each other. In my shop and in my travels
to schools around North America, I have
never found this to be a problem. Tracking
the blade properly on the upper wheel has
always been enough, except in the case of
a severely damaged bandsaw."Given the good case that you and others make that having coplanar wheels is necessary, and the good case that Fortune and others make that is it not necessary, WHAT SHOULD I BELIEVE? Is there any way to get data on this, or are we cursed to make this a religious discussion, and base out beliefs on the beliefs of others. Does anyone know if the manufacturers have tolerances on wheels being coplanar? Will they pay shipping to take a saw back if, like the FWW Powermatic, the wheels are 1/8" out, and not fixable? Thanks,
MelMeasure your output in smiles per board foot.
Mel,
Here I am again with less than definitive proof of the necessity of the wheels being in alignment.
The quote about the Powermatic having plenty of mass and power may be the answer. My Jet is a fairly flimsy machine, which is probably teetering on the edge of being suitable for any kind of demanding work. Change one little adjustment and it could throw that balance out the window.
Powermatic tools that I have seen are more substantial and therefore probably able to operate at a suitable level despite less than prefect adjustment.
Not really helpful, but just a thought.
Rob Millardhttp://www.americanfederalperiod.com
Rob,
Your comment on the Powermatic is quite insightful. Very creative. Thank you very much. I think this issue is very interesting. We have people with "beliefs" on both sides of the issue. We have experts on both sides of the issue. But you may be the one who nailed the issue on the head. I sincerely hope that FWW chimes in and give some thoughts. I have written to John White.I like your post for another reason. As you well know by now, I am in awe of your furniture and of you as a woodworker. We have some (all hobbyists) here on Knots who fawn over expensive tools. We also have folks like you, who make wonderful furniture using tools like the Jet bandsaw that you have, which are on the edge. Folks like you and Ray and Richard convinced me a while back, that the real answer to making great furniture is in acquiring the knowledges and the skills; the tools just need to be adequate.THank you very much.
MelMeasure your output in smiles per board foot.
Mel,
Thanks so much.
Tools, they are important, but since I see all of woodworking through the prism of period furniture, I can't help but to think of how John and Thomas Seymour for instance would look at my shop. No doubt they wouldn't be able to believe the speed and accuracy with which some of the tools can turn out pieces. Of course some tools would look very familiar to them.
In a very real way, I have traded skill for tools; I mean think of how difficult it would be to inlay a something using only hand tools, but with a router and a proper bit, it is simplicity itself.
Rob Millard
Rob,A person who has, unknowingly and unwittingly, affected my thinking on the need for "the best tools" is our own Philip Marcou. He makes beautiful planes. He has published many photos of his shop. All of his tools are second or third hand, and highly refurbished. He does some very clever refurbishment. He makes beautiful tools using tools he has purchased relatively inexpensively and has creatively made to work VERY WELL. He is an entrepreneur and a mechanical genius. He doesn't make excuses. He studies past designs, and uses the great ideas from the past and makes his own innovations -- all with tools which others have gotten rid of. That realization, together with other things I have learned, has led me to my definition of "great woodworker". To me, a Great Woodworker, is one who can make masterpieces using another woodworker's shop. The reason he can do this is that the hallmark of a great woodworker is his sense of independence in the workshop. He knows, deep down in his heart, that he can solve problems as they arise in the shop, and he can find ways to make virtually anything well. That attitude goes beyond a mere set of skills and knowldeges. We have a number of these guys here on Knots as you well know. One last conclusion about great woodworkers -- All of the excellent woodworkers that I have known are very classy folks. Of course, to find clients who can afford fine furniture, you have to be comfortable in conversing with the wealthy. I have been flamed twice today here on Knots. (Not a record). But interestingly enough, I have never been flamed by any of the great woodworkers on Knots. I have never seen you or Ray or Richard or or or flame anyone. There you have it -- my attempt at defining greatness among woodworkers. That and $4 will get you a cup of coffee at Starbucks. Hope I didn't bore you to death. I will let you know what I decide on with regard to a bandsaw. I will probably go with either a Powermatic which is my second choice, but I can get it at a good discount from Woodcraft, or a Grizzly, which Woodcraft doesn't sell. I don't think I could go wrong with either. And I don't think the Seymours are rolling over in their graves waiting to see which one I choose. :-)Have fun.
MelMeasure your output in smiles per board foot.
One point that was touched upon is the guidepost alignment - if it is out then when you adjust for a "tall" cut -- say for resawing -- you may have to adjust the bearings or blocks. This can be a PITA.
Joel,
"One point that was touched upon is the guidepost alignment - if it is out then when you adjust for a "tall" cut -- say for resawing -- you may have to adjust the bearings or blocks. This can be a PITA."You are ABSOLUTELY correct - a real PITA.
MelMeasure your output in smiles per board foot.
I don't think you are going to find a fits all specification. If the wheels are co-planer(or at least close) you will be able to set tracking correctly. If the wheels are out enough that tracking can't be set correctly then the blade will either ride with its teeth on the center of the wheel causing the blade to have some twist with teeth at the cut twisting to the right or if the heel of the blade rides the middle the twist will be to the left as you face the saw. Think of trying to use a hand saw that only had teeth set to one side, poor cut control and trying to twist in the kerf to stay on line.
AB,
What you say sounds logical, but I don't have any proof of this. Sure wish John White would jump in and give his opinion. I did send him a message. I'll bet he is away on vacation and we'll here from him when he gets back.
MelMeasure your output in smiles per board foot.
Mel,
If you think the coplanar is an issue why not get in touch with the manufacturers of the saws that you are interested in buying and ask them for the specs. If you purchase one of them and it is not up to spec you have it in writing. I would think that they have to stand behind what they sell.
Just my .02 cents worth,
Greg
Greg,
Your suggestion is absolutely GREAT. It is what I plan to do. But before I do, I want to learn a bit more. I am in no hurry to buy a bandsaw. I just sold my four year old Rikon 14" bandsaw (the original design, not the Delux). I work at Woodcraft so I use their bandsaw whenever I need one. So I have the luxury of doing some learning. Since I work for Woodcraft, I can get a great deal on any of the tools they sell. They sell Delta, Jet, Rikon and Powermatic bandsaws at the store I work at. Not all Woodcraft stores sell the same stuff, since they are all independently owned. I found the WFF article on "a new breed of 14" bandsaws" to be very useful. After reading what it said about the Rikon Delux, the Delta and the Powermatic, I went to the Woodcraft store, and I took the blade off of each of those, and put it back on and adjusted the guide bearings. I don't agree with all of the findings of the FWW report. It says, for example that the Rikon is hard to adjust and mentions badly cast bearings. To me the reason the Rikon is hard to adjust is twofold:
1) when you screw in on the knob, it moves the bearing out (away) from the blade. This is completely nonintuitive and difficult to get use to.
2) when you tighten the locknut on each of the Rikon guide bearings, it changes position based on the angle you are holding your hand at. To say the system is sloppy is an understatement. I used to own a Rikon so I am used to that sloppiness in system for adjusting the guides.The article says that is is difficult to change the blade on the Rikon. I found it no more difficult than on the Delta or the Powermatic or the Jet.No need to go on with the differences I found. I thank FWW for publishing the article which prompted me to go and find out for myself.But the article did bring up one perplexing issue which I have not been able to resolve. How important is "coplanarity"? The real question is how far out is "too far"? If I knew that, I could check with each of the manufacturers as to what specs they have on coplanarity, and use that in my decision making. This is not a BIG PROBLEM. I find it quite interesting. Someone asked me why I am 'hung up' on this issue. I am not hung up on it. I am merely trying to learn how important something is. This is an intellectual curiosity that I have. I wonder why there is such divergent thinking on the importance of coplanarity. I tend to think that one is better off if the wheels can be made coplanar, but for information that has come out in the rest of this thread, I am guessing that, unless the wheels are way out, then the effect is not worth thinking about. Thanks for the suggestion. You can be sure I will do it.
MelMeasure your output in smiles per board foot.
Mel:
By the replies you've got so far on this subject it appears to me that most people here don't seem to think that the wheels being perfectly coplanar is that important of a deal. I reread the article by Michael Fortune again (which I find to be one of the best articles I've read on setting up a bandsaw) and he does not seem to make much of it either. So if that is the case why would they even bother to publish how many thousands of an inch out of coplanar the wheels on a bandsaw are if at the end of the day it can be out by 1/8" inch and still be considered to be good machine.
Mike
What matters is how the machine works. The dynamics of the system are that the band wants to climb the crown of the wheel and that's what centers the band*. On a decent size saw, the band will never notice 1/8" out of coplanar, and neither will the quality of cut. Coplanar shouldn't affect the band being perpendicular, since that's typically a table adjustment.There was a time when precision measuring devices were expensive enough that the average woodworker never owned any and never worried about how the machine measured up, only how it worked. There's a lot to be said for that approach.Pete*I know there are flat wheel bandsaws, not talking about those right now.
Edited 10/9/2009 9:19 pm ET by PeteBradley
I wouldn't worry too much about them being perfectly CP. Its way more important that under tension the band tracks properly in the centre of each wheel, especially if the tyres are crowned. If not, the tracking on each wheel will fight the other, unnecessarily stressing the band leading to barrel cuts when resawing. My 14" Delta tracks perfectly under tension with the top wheel about 1/8" behind the plane of the lower wheel.
Tuning is important for good performance and well worth the time taken. Tyre surfaces should be concentric to within about 0.020". Guides must be very close to the band without causing any drag, thrust bearings should be very close to the back edge but should not rotate when the saw is idling.
John.
John,
"I wouldn't worry too much about them being perfectly CP. Its way more important that under tension the band tracks properly in the centre of each wheel, especially if the tyres are crowned. If not, the tracking on each wheel will fight the other, unnecessarily stressing the band leading to barrel cuts when resawing. My 14" Delta tracks perfectly under tension with the top wheel about 1/8" behind the plane of the lower wheel."That is good information. Your Delta is 1/8" out of coplanar, just as the FWW Powermatic was, and both of the saws gave great resaw cuts when correctly tuned. Thanks for providing your experience. Having two cases which are very much alike is much more convincingBut there is a section of your second paragraph that I dont understand. You said, "Tuning is important for good performance and well worth the time taken. Tyre surfaces should be concentric to within about 0.020". Guides must be very close to the band without causing any drag, thrust bearings should be very close to the back edge but should not rotate when the saw is idling."The first sentence that tuning is important sounds quite true. Your third sentence that the guide and thrust bearings must be well set iS, to me, one half of the the definition of "correctly tuned". THe other half is that the blades track the centers of the wheels. Interestingly enough, most of what I have read on bandsaws only calls for the top wheel to have the blade track in the middle. I may have forgotten, but I don't remember being told that the bottom wheel should be checked too. Maybe the implication was that with a "good" bandsaw, if the top wheel tracks, the bottom wheel should track. I guess, they were thinking that "coplanar" wheels would give this to you. Who knows?The only question I have about your second paragraph is your sentence ""Tyre surfaces should be concentric to within about 0.020"."What does that mean? How do you measure it?To me "concentric" means "having the same center. What does it mean that the Tire surfaces have the same center? Are you referring to being "out of round"? Looking forward to your answer.Thank you very much.
MelMeasure your output in smiles per board foot.
All,Today, I called the Powermatic Technical Support line, and talked to the tech guy who answered. He was quite friendly and helpful, and was easy to reach. I asked him what would happen if I bought a Powermatic 14" bandsaw, and the wheels could not be made coplanar, such as happened with the Powermatic in the FWW bandsaw comparison.His response was that he gets a lot of questions about that because of that article. He said not to worry whether the wheels are coplanar. He said that the bottom wheel tilts down a bit, thus making a test of coplanarity impossible. My words may not be exactly his, but I am fairly certain that this is what he was saying. He said that the saw must be correctly tuned for good performance. He said to set the guide and thrust bearings well and get the top wheel to track in the center of the wheel, and properly tension the blade, and the saw will perform well. Please note that what he said is exactly what happened in the FWW test. It is also what John (machinist) found with his Delta 14" bandsaw. Somehow, I am not satisfied yet. I guess that if you can get the blade to track in the center of both wheels, then you are OK. However, if that is happening when the wheels are badly (whatever that means) out of coplanarity, then as John the machinist said, the wheels are fighting each other too much, and that places unnecessary stresses on the system.Sure wish that FWW would weigh in on this. Actually, I'd like to see them do an article on this which tests how far out of coplanarity the wheels can be without causing bad performance or longterm damage to the machine. If I learn more, I'll post another message. Until then, I sure would like to hear from others. We haven't gotten this thing figured out yet.Thanks,
MelMeasure your output in smiles per board foot.
How do you people get any work done? Are you incapable of the little adjustments required in manipulating the wood ? Is you eye hand coordination so poor that the machine must be absolutely perfect? Are your expectations really that high for a tool that sells for so little for how much it does?
................................................
Men will never be free until the last king is strangled with the entrails of the last priest.~ Denis Diderot
Don,
Always good to hear from you.
Your point is well taken - just tweak the tool to make it work.
Well, the FWW article on 14" bandsaws showed the Powermatic having its wheels out of coplanar by 1/8" and said that it couldn't be fixed because there was no room on the arbor for adding shims.So, tell me, how would you make the adjustment?Thanks,
Mel.
PS good to see that you haven't lost your edge. :-)PPS to use your words -- Tell me, Don, How do you get anything done when you spend so much time reading stuff that you find trivial? Why not just ignore it if it is so bad? (rhetorical question - I know the answer is "because you can't help yourself. you are drawn to it like a moth to a flame." PPPS -- I love puzzles. Lots of people do. I don't know why. YOu could consider them as merely a way to waste time. Of course, you could also look at them as a way of doing mental exercise in an enjoyable way. WELLLLLLLLLL - I found the conundrum of a "non-coplanar bandsaw wheels on a machine that cuts well" to be an interesting, nay, a VERY interesting intellectual puzzle. FWW said that it couldn't be fixed. Others have said that it doesn't need to be fixed. Others have said that it is irrelevant. You have urged that people just fix it and be done with it. OF COURSE, you failed to indicate how the adjustment would be made. Tell me this isn't an interesting, intellectual puzzle. In fact, there are two puzzles here. One is about the conundrum of "is non-co-planar OK". The other is why there are two religions with opposite beliefs. Have fun. I am. By the way, I believe I have figured out how to make the adjustment. Let me know how you think you would do it, and I will post what I have just come up with. I don't know why this simple fix didn't occur to one of us much earlier in the game.Long live puzzles!!!!!Measure your output in smiles per board foot.
Hi Mel,
I believe I clearly indicated that the adjustment was to be made by manipulating the wood.
................................................
Men will never be free until the last king is strangled with the entrails of the last priest.~ Denis Diderot
Mel,You've moved from asking whether something matters to fixating on something meaningless. The PM guy was very polite (although he's wrong about the tilted wheel), but I'm sure he's tired of these calls. MMove along, nothing to see here.Pete
Pete<
I may have gotten the answer from the Powermatic tech guy. I asked him about installing the riser block. He said to put the nut on loosely and then rotate the top section slightly in each direction until the blade stays in the middle of the wheels. This could be it. Maybe the FWW Powermatic which had its wheels off by 1/8" was merely assembled incorrectly. Could it be that all they had to do was loosen the riser block bolt, and move the top section in the needed direction a small amount, and the two wheels would have been coplanar? Could it be as simple as that?
MelMeasure your output in smiles per board foot.
Mel,"Could it be as simple as that?"Yes.And to paraphrase Pete, you're continuing to fixate on the meaningless. Go cut some wood.Rich
Pete,
Thanks, I was beginning to wonder why my band saw wheels aren't co-planar and yet the blades all ride smack dab in the center of the crown. Kinda funny but they track that way under load too.
Riding the crown works for me even without co-planar wheels. I think I'm on to something.
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Bob,"Riding the crown works for me even without co-planar wheels."It's great on country roads but I get in trouble on the freeway...the crown is filled with grass so I keep drifting :)BB
Bob,
I wonder if the fact that you get good results without co-planer wheels means the band is actually riding a little bit out of plumb? By that I mean maybe the band is tilted a bit front to back (not side to side) as it goes around the wheels.
That wouldn't affect the cut of course. So maybe the band kind of self-adjusts to the wheels not being co-planer - and that's why it's not a major deal.
I wonder if any of the huge, industrial-age monster band saws have co-planer wheels? Given some of the manufacturing tolerances back then, I wouldn't be surprised to learn that that wasn't considered important enough to do anything about. But I could be wrong.
Disclosure: I could be wrong.
ZoltonIf you see a possum running around in here, kill it. It's not a pet. - Jackie Moon
>> Disclosure: I could be wrongClose. Don't confuse "plumb" with perpendicular. All that really matters is that the band is perp to the table. That's usually dialed in with a table adjustment, coplanar doesn't come into it.Pete
Edited 10/11/2009 6:39 pm ET by PeteBradley
Pete,
What I'd be curious to know is can you have wheels that are not co-planar and yet the blade tracks centered on the crown of the wheel. I'm assuming the answer is yes.
Also does a center tracking blade reduce/eliminate drift?
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
The band doesn't really care about coplanar (unless it's totally out to lunch), it's just trying to find the high point of the wheel. The tracking knob is really just an adjustment of where on the wheel that high point is. On mine, the track knob will hold the band pretty much anywhere from side to side on the wheel, though I always center it.If you think about it, 1/8" out of coplanar equates to a fraction of a degree on most saws. There are lots of other adjustments that will trash a saw's performance much more easily.I don't claim to be an expert on drift, but Michael Fortune recommends using the track knob to adjust for it. The notion is that adjusting the band back and forth on the crown will adjust the angle of the band relative to the miter slot. Pete
Pete,
The notion is that adjusting the band back and forth on the crown will adjust the angle of the band relative to the miter slot.
Ahhhhh, that's where I was headed with my question. If you can keep the band riding the crown, then set the guides close, they help to keep it there whilst sawing. If the band starts fighting with the guides then your not there yet. I would also think that feed rate enters into the equation as well.
If the band wants to work its way to one side or the other of the crown this action is the cause of blade drift? Or at least one cause. Seems like an insignificant amount but when you take that across a board of any significant length it gets a lot worse as the cut progresses, yes?
So my take is that there isn't one single thing that can eliminate drift - it's a combination of many different things. Perfectly co-planar wheels are not mandatory. We may be revisiting information from previous posts on this but it is very good info.
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Bob,
I adjust my bandsaw blades to ride on the rear of the upper crowned wheel. This does introduce blade drift, because the blade is ever so slightly skewed as it comes to the guides and the cool blocks don't seem to be able to overcome it. I have not paid enough attention to where the blade tracks on the bottom wheel, but I wonder if when my saw mysteriously went from co-planar to not, if it was riding on the crown or forward of the crown on the bottom wheel. This would mean the saw is fighting to track properly and would have to have some negative affect on the cut.
I remember after the violent blade break, finding it impossible to track a 3/16" wide blade. It would refuse to ride where I wanted it to and just the slightest adjustment of the tracking knobs would move the blade to the front or back, nearly off the wheel. Now with the wheels in alignment there is no problem tracking that blade.
All of this tells me that at least with my light duty machine, being co-planar is important.
Rob Millardhttp://www.americanfederalperiod.com
Rob,
I guess I was trying to say as long as the wheels are adjustable to be co planar I should think you're good to go. Does that make sense? Just curious about how far out they could be and still track the blade on the crown.
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Bob,
The question you asked Rob was essentially the one I started this thread with. I never got an answer. We all talked around the issue. Many tried to help, but it seems there are two camps. One says to try to get as coplanar as possible. The other says, which includes Michael Fortune's article in FWW says that it isn't worth worrying about. There seems to be as much "rationale" for one side as for another, but no data for either.The FWW article on "a new breed of bandsaws" provided "out of coplanar" measurements for each of the bandsaws. They highly recommend the Powermatic which was the fartherst out, and wasn't fixable. It also performed very well in the tests.Hard to make sense out of all this. I am coming to believe that it is the same story as "pins first" or "tails first" -- it's all religion. I sure wish there was some real data on how far out of coplanar the wheels can be before trouble occurs. I called Powermatic today and talked to the techie. This is the second techie I have talked to at Powermatic. Both recommended against using shims and said not to worry about the wheels not being coplanar because it just isn't a problem.So which religion do you belong to?This would be a wonderful issue for FWW to tackle for an article. Start with five bandsaws, each exactly coplanar. Then start moving each out of coplanarity by a sixteenth of an inch at a time, and then checking to see how well it does resawing. There must be a number past which the bandsaws just don't operate well. The reason is that if the wheels are not coplanar, and you have the blade track in the middle of the top one, then it will not run in the middle of the bottom one. Since the wheels are no more than an inch or an inch and a half wide, the blade will fall off the bottom wheel. Very interesting, isn't it? Earlier in the thread, I wrote to John White, but he hasn't written back yet. Maybe he is on vacation. Have fun. Maybe you can use your influence with FWW to get the technical folks to do a little study for an article. It would be a VERY USEFUL article for lots of folks.MelMeasure your output in smiles per board foot.
Mel,
Three's the number, like in the third post. BB has it right. Jeez Mel, ye gotta read them responses ye know.
Me, I aint got no religion when it somes to bandsaws. Now a TS is something entirely different.
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Bob,
I had read BB's post back when he wrote it. It is very much in line with the FWW article by Michael Fortune, and completely the opposite of the FWW article by Duginski (and also Duginski's book}. Lonnie Bird's Bandsaw book makes the point that you should have coplanar wheels but it doesn't say much else about it. It still comes down to the Fortune religion or the Duginski religion. If you read all of the posts, you will see that most belong to one of the two religions. My point to you in my last message to you still stands -- FWW could easily do a very good (and still cheap and quick) test to get REAL DATA on this issue. I believe such data would take this issue out of the realm of religion and put it to rest based on data. I don't believe we'll see such an article. As a result, I have joined the Fortune/Boilerbay religion, and ordered a Powermatic. Without data, there is no point in continuing the conversation. Note: There is another interesting Religious War in the Bandsaw Arena. Should you super-tension your blade when re-sawing (Lonnie Bird), or should you tension the blade as the manufacturers recommend (Michael Fortune). Sure wish we had real data on that. Until real data shows up on this, I will stick with the Michael Fortune religion. I just read that you got some tools stolen. I am sorry to hear that.
MelMeasure your output in smiles per board foot.
All of this is interesting, but, my little bandsaw has THREE wheels. I also run a 1/8" "scroll blade on it all the time. All three wheels seem to like the blade just short of the "high point" of the crown on the wheels. About half way between the edge of the wheels (tooth side of the blade) and the "top of the crown". Just a thought." Although I have the right to remain stupid, I try not to abuse that right"
Dog,
If your blade likes that position and is working well, then I would keep the blade happy. Nothing beats success! WHat do you make with your 1/8" blade?
MelMeasure your output in smiles per board foot.
I do a wee bit of "scroll work" with this saw, scalloped edges, small reindeers and sleighs, shelf brackets and such. As for blade tension, I listen to the blade as I tension it. I "play" the blade like a guitar string until it has a nice "ring" to it. I did have to replace a tire last year, top tire had dry-rotted away. So, since a Dirtdevil sweeper belt is the same size, that was used for the tire. Being running just fine ever since. That "left-over 1x8x6" plank that I made a small chair from, was made using this saw. Go to the end of the "Table with a floating top" thread for a picture or two." Although I have the right to remain stupid, I try not to abuse that right"
Dog,
You got a good attitude! Go get em.
MelMeasure your output in smiles per board foot.
Whitedog,Get a larger blade or put a shims under the right side of the saw bottom?
Just kidding. If it works, worry about the wood, forget about the machine. There are a lot of good tricycles out there.BB
I really don't think there are two camps. Like many tool dimensions, there is a level of accuracy that's required beyond which further improvement is unnecessary. Obviously if a band saw is 2" out of coplanar, you've got a problem. As numerous people have pointed out small amounts of coplanar are not.Why does FWW keep including meaningless measurements in its reviews? That's a separate discussion. FWW has gotten a lot better than the days when they posted router runout to 1/10000, or claimed that the depth of finish could be determined by viscosity measurements. There's still a need to recognize when measurements better than "good enough" are red herrings.Pete
Pete,
I fully agree with you on getting things "good enough". Did you read about the guy who dropped the bandsaw table on his foot while trying to adjust the wheels for coplanar? EGAD! I wish that FWW had said in their Bandsaw review, the words of Michael Fortune in his FWW article, where he said that as he travelled the world, he hadn't seen that the coplanar thing was an issue worth worrying about! Fortune's article is probably the best one on bandsaws, IMHO.Have fun.
MelMeasure your output in smiles per board foot.
Mel
I think part of the reason the answer you seek is so elusive is the number of variables involved. What is coplaner? Some may be looking at one aspect while others another.
The optimum would be for both wheels when say viewed from the top to have both faces form a single line. If the bottom wheel is moved in or out on its axis (shaft) then the wheels would still be parallel but not coplaner. This condition however is easily compensated for by adjusting tracking with the worst side affect being the cutting edge of the blade is not perpendicular to the table and or parallel to the vertical travel of the guide bar.
If the axis of the bottom wheel and the top wheel are not parallel however then the faces of the wheels when viewed from the top would form an X. The more severe this X is the more it puts a twist in the blade which affects being able to track the blade and also introduces drift problems. If you visualize it severe enough the blade could actually lead different on a tall cut than it does on a shallow cut. This type of coplaner problem may be hard to fix, although it was addressed in an earlier post about setting up a riser kit.
This may be part of why there appears to be two "camps" with differing opinions about the importance of coplaner. I think it is more important for them to be parallel than coplaner. Simply laying a straightedge across the wheels at their center does not tell the whole story and could be misleading. Just like jointer tables they also need to be checked in an x pattern. I believe any saw that is out of parallel could be adjusted, BUT, that adjustment could vary from goof proof simple to not worth it major rebuild. Most tool comparisons only do a simple check so you may not be getting enough info to make an informed purchase.
If it does the task you require of it then it ain't broke. Make sawdust till it is.
RichThe Professional Termite
Rich,
I had fun thinking about this. I have come to the conclusion that the only real point to look at in the FWW article on bandsaws is how well each cut. The Powermatic was the second best. Laguna was first. The Powermatic wheels were 1/8" out of coplanar, and still gave a better cut than all of the saws except one. That is the important thing.
I have ordered the Powermatic, and If it comes in at 1/8" out of coplaner and cuts well, I am going to leave it alone.
THanks for writing.
MelMeasure your output in smiles per board foot.
I know you like a good mental workout and when a bandsaw does not cut right it can be tough to figure out sometimes. Maybe not quite as hard as trajectories but certainly less predictable. In one shop I worked in years ago we had a 38" Tannewitz, nicknamed the tanglewitch, for its ability to mangle blades when they broke, which was often. Guys would put a new blade on and usually the air would turn rather blue from the comments while trying to track the new blade. Even once it did settle in you could not cut to a line as the blade would wander all over side to side and front to back. We didn't use the saw much with two 36" and a 30" that behaved but when you needed the extra depth or height it was tolerated.
The wheels on this saw were easily 2 1/2" wide and you never knew where the blade would finally settle in. The saw had a little window to look through so there was no need to have the top cover open while adjusting it. One day as another guy was messin with it I watched through the window and could see the blade actually jump about 1/2" forward or back on the tire. I had him shut it down and opened it up for a look. The tires on this beast were so grooved and chewed up from breaking blades they looked like a fresh plowed field. Took a sanding block with some 60 grit paper and with the saw running smoothed out and recrowned the tires.
Suddenly this saw started to get lots of use. It was an easy fix that untill then went undiagnosed because when looking through the little dust coated window you couldnt see the grooves in the tires. Sometimes you need to look at what the instructions don't tell you.
Rich The Professional Termite
Rich,
Very interesting story. Good lesson learned. THank you. There is an old saying that in problem solving, you should let the situation suggest the solution, not preconceived notions. There was a physicist named Richard Feynman. I read about his early life. When just a kid, he used to make money by fixing radios. Adults were amazed at what he could do. He said it was usually very easy. He just unscrewed the back of the radio and looked for any tubes that were black or were leaking. Then he would replace that tube and all would be well. He said, "All you had to do was look". That was pretty much the story you told.I think that 14" bandsaws are not as difficult to diagnose as the big one you talked about. There are a lot of them around and there is a lot of experience with them. From what I can see, they are pretty simple and reliable, for the most part. Indeed they are "forgiving". The non-coplanar wheels on the FWW Powermatic that cut very well is a prime example.I am learning a bit about "woodworker psychology". FWW likes to do complex reviews that get data on lots of parameters when they do a tool review. THAT"S THE PROBLEM. The focus shoulde be on Performance. Heck with the bandsaws, the one farthest out on one parameter, actually did great cutting. The only implication is that the parameter was not important.If you want to find out how much of a problem that caused, call Powermatic's tech service number and ask about "coplanar" wheels on bandsaws. They seem to be sick of hearing about it. An eighth of an inch is not worth worrying about. Yet it has caused a number of potential buyers to worry about it.There is another thread now on bandsaws and the OP asked how important "ease of blade changes" is to making the decision as to which bandsaw to buy. Samson answered brilliantly, saying that you shouldn't base that decision on how easy it is to change a blade. FOCUS ON HOW WELL THE SAW PERFORMS. Sounds right to me.Thanks for writing. Great story you told.
MelMeasure your output in smiles per board foot.
Yes I mean the tyre surfaces should be round or not vary in distance from the centre by more than about +/- 0.020".
This is best measured with a dial gauge but could be done with feeler gauges.
It is possible in some cases where the tyre is proud of the rim to dress the tyre round with a rigidly fixed drum sander.
If the band shifts sideways every time a wheel goes around a more uneven cut will be made and additional wear will occur on the guides and energy is lost.
John.
Ah, I am so glad I have stumbled across this thread. I just purchased my first bandsaw, a Jet 14" Deluxe Pro (12" resaw height). I bought a few Olson blades along with the saw, and immediately took the OEM blade off after I got the saw set up.
Putting a 1/2" blade on the saw, I have no trouble getting the blade to run true and centered on both wheels.
Then I tried a 1/8" blade, and that’s where the problems started. I can get the blade to track in the center of the upper wheel when I hand-spin the wheels, but as soon as I power up, the blade runs out to the left edge of the wheel (I’ve stopped it before it falls off). I have adjusted the upper wheel tilt with the saw running, to get the blade to stay on the upper wheel. However, when adjusting the wheel tilt to get the blade to drift toward the center of the upper wheel, I get to a point prior to the center where the blade suddenly speeds across center and runs to the back edge of the wheel. If I back off on the wheel tilt, the same thing happens in reverse.
So I called Jet. The technical service rep told me a couple things. First, he said that the coplanar thing is all nonsense, and that the Jet wheels were designed not to be coplanar. Second, he said that the blade doesn’t have to track on the center of the wheel – it’s just fine if it tracks to one side of center, and, incidentally, when that is the case, you will find that the blade is tracking on the opposite side of center on the lower wheel. He recommended adjusting the wheel tilt to where the 1/8” blade is relatively close to center and just leave it there.
OK, fine. I start the process again, this time leaving the blade about 1/4” to left of center of the upper wheel. By the way, the blade is also tracking to the left on the lower wheel, not to the right, as Jet suggested it would be.
Now I bring my upper thrust bearing in just behind the blade, then bring the guide bearings in.
Now I go to the lower thrust bearing, and discover that at full travel, it’s still 1/8” away from the blade. I cannot get the thrust bearing to extend far enough.
Oh – another thing. When I power off the saw and the blade slows down, it shifts 1/8” or more to the right, or until it hits the thrust bearings, whichever comes first. Without touching anything, when I power the saw back up, the blade drifts back to the left.
While I’m at it, I pull the table off, open the doors, and lay an extruded aluminum cutting guide across the rim of the lower wheel. At the other end, there is about 1/8” gap between the straightedge and the upper wheel rim after I adjust wheel tilt to even out the gap.
Something smells fishy here. I haven’t yet looked into shimming wheels, but I have a sneaking suspicion that I’m not going to have enough travel to move a wheel over 1/8”.
I, too, am very interested in hearing John White’s response.
Dave
It might not be so much as the wheels being out of line as it might be the "crown" of the wheels "tires" are a bit too much. Less "crown" to the tires might help out here.
" Although I have the right to remain stupid, I try not to abuse that right"
Hmm. Well it's a brand-spankin' new saw, hasn't cut more than 10 feet of board 1" thick. I'd expect if it was excessive crown, then there'd be a bunch of other unhappy campers out there with my problem.
Maybe you got a bad set of tires then? Take a square, lay it against a wheel, and see just how much crown you do have. Sounds like both a "high" center crown, and either the top wheel or the bottom wheel needs to be shimed out. There may be a bearing issue in the top wheel, causing the blade to move around like that. I'd also check BEHIND the lower wheel and see if there is something holding the wheel out that far. " Although I have the right to remain stupid, I try not to abuse that right"
Dave,
I called the Powermatic/Jet Tech people and they told me the same thing about coplanar being not important. I take that with two grains of salt.Glad the 1/2" blade worked well. About the 1/8" blade. I thought that you couldn't use less than 3/16" blades on bandsaws with the circular bearings. You can use very narrow blades on the cool blocks. Check into that. I have never used less than 1/4"Keep us posted on what happens.
Thanks,
MelMeasure your output in smiles per board foot.
Dave,Obviously you have one terribly unstable band saw. That is simply unacceptable behavior. In addition to a problem with the tires, I'm going to suggest one other thing.As I've said in an earlier message, I've not had extensive experience with band saws as has Michael Fortune, but the experience I've had with 4 very different machines, parallels his. However, I've realized there is a condition that everyone in this thread has not mentioned, including me. We've all talked about wheels being co-planar or non-co-planar. I may be wrong, but I think we have all assumed, that even if non-co-planar, the two wheels were still parallel to each other IN BOTH PLANES. And if non-co-planar, just misaligned along the axis.The tracking adjustment changes the orientation in the vertical plane, therefore can compensate for any misalignment in that plane. But what if the wheels are not parallel IN THE HORIZONTAL PLANE? I suppose there's a certain tolerance within which misalignment will not be that critical. But if the wheels are out of line too much, I think the condition you're describing could very well happen.Maybe we also should check for parallelism in the horizontal plane.Rich
Rich,
Not a lot unlike aligning the front end of a car.....
Caster, camber, etc. Uhoh, I said camber.
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Bob,Caster, camber. Yeah. I didn't know the words to use.I was thinking pitch and yaw.Rich
Rich,
Skow-wow is the technical term I believe for the condition you are attempting to describe. Usage: "Those bandsaw wheels are totally skow-wow."
Ray
My name keeps popping up in this discussion so I guess I'll offer an opinion:Nobody knows if coplanar band saw wheels are important. Despite having been discussed for years no one has ever actually run a well designed experiment to actually test what happens when wheels are or are not coplanar. Until somebody does run that experiment it is all speculation.John White
Shop Manager for FWW Magazine, 1998 to 2007
John, I completely agree with you, but your statement prompts a question. Please take a look at this article from 2007:
https://www.finewoodworking.com/fwnpdf/011193048.pdf
You'll note on the second page there is a large sidebar stating unequivocally that non coplanar wheels are horrible as they will prevent your blade from tracking properly. In this side bar and in the summary table, Powermatic's saw is dinged for lack of coplanar wheels. Given your statement that this is mere speculation, I guess I'd be pretty miffed if I was Powermatic. Imagine how many sales they lost because your author damned them based upon speculation in the most prominent woodwroking magazine for hobbiests.
Were you still shop manager when this article went out? Did you comment at the time about this speculative charge?
I was the Shop Manager when the machines were tested, I did much, or all, of the assembly and measured how well the wheels on each machine were in line. I did not write the article or the sidebar and I don't recall being asked specifically about the importance of coplanar wheels, it was assumed that this was important based on earlier articles and books. In any case, my opinion about coplanar wheels has changed since I left FWW, the more I have learned and read about the subject, the more I am convinced that until someone runs a good experiment nobody really knows how important it is for a machine's wheels to be coplanar.John White
Shop Manager for FWW Magazine, 1998 to 2007
Thanks for the straight answer.
FWIW, I have the Powermatic - got it a couple years before your article - and have never had an issue at all. I've taken Mike Fortune's advice (from his exceptional FWW article) on how to set it up and find it resaws and does everything else I ask of it like a charm.
John,
Thank you very much for jumping in on this thread. I understand that you won't have an opinion on coplanarity until a study is done. So here is my question to you (for your wisdom, and not for "facts".) I just bought the Powermatic. I took delivery yesterday, and will set it up in a few days. All of the Powermatics and Jets that I checked were out of coplanar by about an eighth of an inch, just like the one in the FWW article. Yet, the FWW Powermatic cut very well. Samson's Powermatic cuts very well. SO, --- what do you recommend to someone, like me, who gets a saw like the Powermatic,? If mine is out of coplanar by the 1/8" or so, do you recommend that I just use it and see how it works, OR, should I do what the Powermatic tech recommended, and drill out the holes in the bottom of the riser block and make the wheels more coplanar, and see how that works?I am tending to think that I should just leave it alone and see how it actually cuts, and if it cuts well, then not make the wheels more coplanar. I can always try that later.Any advice on a practical approach, in the absence of scientific data, would be greatly appreciated.Thank you very much.
MelMeasure your output in smiles per board foot.
Mel,The whole purpose of the tool is to cut wood. If you put a sharp new blade, of the proper type for the job, on the saw and it cuts well, then you should leave it alone. Later, if the saw doesn't seem to cut as well, put another new blade on it and you will probably find that it cuts well again.One of the basic rules of machine repair is "If it ain't broke, don't fix it."John White
Shop Manager for FWW Magazine, 1998 to 2007
John,
Thank you very much. I opened this thread to get some information. It has gone on and on, with posts all over the place. You have the weight to bring closure, and you did. As you said, the issue needs some data before one can form a valid conclusion. So until then, your advice is to see if the saw cuts well, and to leave it alone if it does. We have reached a point beyond which only data, not words, can shed further light. I believe this thread will help a lot of folks. It can also lead to an article in FWW to shed light on the issue. I would think that good data could be gotten by taking a few bandsaws which are have coplanar wheels, and make test cuts, then take the top wheels 1/16" out, and test cut again, then 1/8" out, and more test cuts, and so on until the belt almost comes off of the wheels, and check to see if there is any degradation in the quality of the cut.THe article could also do one more thing. The previous article said that the Powermatic cut very well but was 1/8" out of coplanar, and that could not be fixed. Well, I hear that by drilling larger holes in the bottom of the riser block allows the two wheels to be made coplanar. It would be good to check to see if any increase in the goodness of the cuts results from that. You have a lot more clout with the editors of FWW than I do. Is there any chance you would ask them if they might do such an article. It wouldn't cost much because it could be done on site with exiting equipment and existing personnel, and no travel costs, etc. It would also be quite useful. Thanks,
MelMeasure your output in smiles per board foot.
I'll actually be at FWW tomorrow to shoot some videos so I'll get a chance to float the idea to the editors. As valuable as the information would be, my gut instinct is that the subject has limited appeal for a magazine article, but I might be surprised.John White
Shop Manager for FWW Magazine, 1998 to 2007
I for one would like to see FWW concentrate on making chips, not measuring machine parts. There are plenty of good band saw tune-up references already that are actually useful. In general a machine review should be extremely sparing with "precision" measurements and focus on how the machine works in actual use.Pete
Right ON!
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Pete,
"I for one would like to see FWW concentrate on making chips, not measuring machine parts. There are plenty of good band saw tune-up references already that are actually useful."I started this thread because FWW has published articles saying that coplanar is important, and that coplanar is unimportant. Then they published an article that compared a bunch of bandsaws for resawing and said that the Powermatic was the second best at resawing but that it was the furthest out of coplanar, and it couldn't be fixed. I called Powermatic, and found that they have been flooded with calls about the FWW article asking about the FWW article. So FWW has been the initiator of a dilemma for people who are about to buy a bandsaw, and for owners of the Powermatic. John White said that he didn't know what the real answer is, and we won't know until data is gathered. Given that FWW was the start of this bifurcated situation, and that it wouldn't be hard for FWW to do a test of whether saw cuts get worse as a saw gets farther out of coplanarity. This wouldn't have to be a long article. Half a page would do just fine. If I were a FWW editor, I would feel it was my DUTY to do such a test, given the opposing views that FWW published in the past, and the seemingly contradictory information in the test in which the Powermatic performed admirably but was the furthest out of coplanar. I hope this issue affects FWW in two ways. One, I hope they do the test and publish the findings. SECONDLY, I agree with your statement "In general a machine review should be extremely sparing with "precision" measurements and focus on how the machine works in actual use." I hope that FWW adopts your recommendation in all further tool tests. EXCELLENT IDEA. Make recommendations based on actual performance.Have fun.
MelMeasure your output in smiles per board foot.
Mel,
If I were a FWW editor, I would feel it was my DUTY to do such a test
Ye know I think you are the man for the job with all the effort you've put into this topic. If I can help ye let me know.
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Rich
I think it has been addressed ;o) 48211.75
RichThe Professional Termite
JOMT,Why not return the Jet saw to the place you bought it? I think it would be good to get rid of it before you make a lot of changes, after which you could be be blamed for screwing it up. If you can return it, I would recommend going with another type of saw. The FWW article found that the Jet, at 1 1/4 HP, was underpowered. And they didn't have the problems you are having. Instead of trying to fix it, and getting stuck with a problematic saw, see about using the warrantee to have JET repair it or replace it. If they won't, tell them that everyone on Knots will find out about it, and that won't be good for business.Let me know what happens.
MelMeasure your output in smiles per board foot.
Return would be a bit of a pain - it was ordered via Amazon and shipped freight.I'm not planning on doing a lot with it, it's my starter saw, and at this point I'm just getting started in woodworking. OK, well, I've been just getting started in woodworking for about 25 years now, but I finally got my first band saw ;)However, I called Jet back and talked to a second guy. He said my symptoms don't sound normal. He told me to loosen the four bolts that hold the top to the bottom, then rotate the two halves to bring the wheels more in line, and re-tighten the bolts. If that doesn't work, he sounds like the kind of guy who is going to make things right. Will keep ya posted.Unfortunately, getting a tool on all four of those suckers is proving to be a project in its own right. Looks like I gotta pull the lower wheel off, since the inner two fasteners are upside down in the wheel cavity. To pull the lower wheel off, I gotta loosen the motor mount. Gee whiz. Now if I hadn't been sick for the past 4 days, plus had a water leak in the utility room, a broken toilet valve, a collapsed retaining wall out front, clogged gutters and a lawn that needs one more mowing....
Just,
Wow. What a story. I hope things work out for you. Please post an update when you have more news. Information like this will help others make better decisions.
Thank you.
MelMeasure your output in smiles per board foot.
Just to be clear, the Jet rep told you to loosen the saw from the base cabinet which would change the drive belt alignment only, to try to fix a tracking problem with small blades? Doesn't sound right.John White
Shop Manager for FWW Magazine, 1998 to 2007
John,The rep said to loosen the joint between the upper arm frame and lower base frame (where you would normally insert a riser block, except that my saw has the extra 6" of frame height built-in), then "twist" the upper arm frame assembly to bring the upper wheel in line with the lower wheel (the theory is that it's currently not in line).The motor is actually mounted directly to the lower base frame along with the lower wheel. Removing the base cabinet would remove just that - the cabinet. You'd still have a fully-functional saw left over, just made for really short people.Dave
You mentioned having to loosen four hard to reach bolts to make the adjustment, on all of the 14" saws I am familiar with there is just one very large center bolt that attaches the upper and lower frames together. These saws are typically held to the base cabinet with four bolts which is why I thought that was what you were told to loosen.PS: I just went to the Jet web site and got a look at the saw, and it does indeed have four bolts holding the upper and lower frames together. Usually these saws have a pin or two, hidden inside the joint where they can't be seen, that actually hold the parts in alignment. The bolt, or bolts in your case, usually only serve to hold the two halves together. If your saw is built this way there will be little if any movement even if you loosen the four bolts.John White
Shop Manager for FWW Magazine, 1998 to 2007Edited 10/28/2009 2:47 pm ET by JohnWW
Edited 10/28/2009 2:53 pm ET by JohnWW
John,Yeah, as a mechanical engineer, I'm pretty familiar with pinned & bolted joints - and I specifically questioned the Jet rep on that when he advised me to loosen & reposition the joint. I figured they'd pin & bolt the joint, then do a final machining operation to locate the wheel bearing bores as a set - but apparently there's enough opportunity to get that tweaked over the life of the saw that they felt it best to leave the joint unpinned for "adjustment."Guess I get to adjust mine out of the gate.DavePS: Appreciate your extra effort to investigate and help out!
I wonder if you have tried more than one 1/8 inch blade? It might be just a bum blade that wasn't aligned properly when it was welded.
One thing I found is coplanar measurements change if you check with no tension or with tension. And also change with different blade widths all with the same tension reading, using a gauge. I'm starting to think if it cuts well who cares about whether it's coplanar or not. It's obvious on my saw the column is flexing when tension is increased. Good luck with your saw, let us all know how things are working out.
okahun
okahun,
I believe you have hit the nail on the head.
MelMeasure your output in smiles per board foot.
This forum post is now archived. Commenting has been disabled