I have a General 10 inch contractor’s table saw. Great saw, but old style blade guard that does not travel up and down with the blade. I generally cut plywood and 1x stock on the saw for finish carpentry projects so the blade is usually pretty low. Would I be better of leaving the blade fully up so the stock splitter is close to the blade (like a riving knife) or adjusting it down to the depth of the material being cut (which is generally recommended).
Thanks for your thoughts.
FR
Replies
Raise the blade only the minimum required to clear the stock being cut.
Adjust the blade according to the thickness of the work.
Chris @ www.flairwoodwork.spaces.live.com
- Success is not the key to happines. Happiness is the key to success. If you love what you are doing, you will be successful. - Albert Schweitzer
It's unanimous. Thanks guys. FR
Make a new splitter plate to fit your saw that hugs the blade like a riving knife at the blade height you use. Just don't raise the blade into it - I have a cloth cover I put on the handwheel which reminds me to change splitters when I reach for the wheel to raise the blade.
I personally think the blade should always be at full height when you are through cutting. The angle of attack and distance from the table to the top of the blade, both seem to me as lessening the probability of kick back.
But the common wisdom is to keep the blade set low so that the gussets between the tips, just clears the top of the board being cut.
I agree with "Jigs" on this one. I run mine full height as the downward motion of the front cutting teeth help hold stock down and... I find I get a cleaner cut with less blade heating. That is especially true with thick hard-wood. And it is closer to the splitter as mentioned.
I personally believe that running the blade with just the gullet above is recommended by manufacturers for safety as not as many teeth are exposed. But.. they also take into account that the vast majority take off the plastic shield and it never see's the TS again with an American style saw.
So... if you do not use your shield I would run it low.. and if you have the shield on which I do for 95% of my cuts I would run it high. I feel there is no additional danger running it high if the blade is completely covered and you add efficiency with the downward angle.
Sarge..
Edited 11/23/2008 10:59 am ET by SARGEgrinder47
Sarge,
Very interesting note here about blade height! I've wondered about that myself - whether to just set one blade height and forget it, or wind the blade up and down to accommodate different thickness materials.
Your point about safety being the reason for the latter technique - rather than, perhaps, cleanliness of the cut - is something that would be worth testing. I'm not brave enough to do it myself and subject the results to this critical audience. But you have thicker skin and seem to be made of sterner stuff. What do you say? Are you willing to give it a go?
Zolton
If you see a possum running around in here, kill it. It's not a pet. - Jackie Moon
My 1 cent:I am under the impression that the recommendation to lower the blade as far as possible is to:
1. Minimise damage to the veneer om plywood, coated melamine etc.
2. Minimise impact damage to the teeth and the work. The higher the blade is, the teeth are going to come down more "square" onto the surface instead of slicing into it.This is based on the manuals that come with handheld circular saws and the rules may be different for a table saw. I like the idea that the blade helps keep the workpiece down.My TS is a Skil 7 1/4" handheld mounted in a Wolfcraft machine table and it is difficult to adjust the blade height so I have been tending to keep the blade high. This is recently bought kit and I have only been cutting beech and pine on it so I cannot claim much experience. However with handheld circular saws the "rules" do make a positive difference.
I simply keep mine high for the reasons I mentioned. I used to raise it to the bottom of the center tooth gullet but... after trying it up I was getting better cuts. But note... I do a very minimum of sheet goods. Maybe 3-4 a year after breaking them down with a circular saw and then storing in my wood rack bottom for sheets. Then taking the smaller section to the TS for sizing for drawer bottoms and chest backs.
In those rare cases I do lower the blade about an inch lower than maximum height. But... for all ripping and the few cross-cuts I do the blade stays high. I simply just feel it gives me a better cut especially when ripping.
"Your point about safety being the reason for the latter technique - rather than, perhaps, cleanliness of the cut - is something that would be worth testing. I'm not brave enough to do it myself and subject the results to this critical audience. But you have thicker skin and seem to be made of sterner stuff. What do you say? Are you willing to give it a go"? .... Zolton
Not quite sure what you refer to here exactly. I have been using the raised blade method quite a while now. My blade stays under cover of the shield... I use support left and right of the blade and stock.. and I never let my hands travel closer than 8" of the blade. I also use a crown guard under the plastic shield to counter a kick-back being thrown straight up. Not much chance of me getting a hand in the blade as I see it.
Regards...
Sarge..
Sarge... nice wheels!
Thanks everyone. From my read, the consensus is either (1) leave the blade at full height or (2) make a fixed height riving knife to accommodate the blade height for 3/4 inch sheet goods and/or 1x material (which is 80% of what I cut). There is no consensus on which method is "better". FR
The reason there doesn't appear to be a consensus is that there are some caveats here; In general, having the blade full-height makes the likelyhood of certain kinds of kick-back much lower and makes a splitter work better (closer to the blade); however, it also exposes you to more of the blade, potentially increasing the risk of an amputation or severe wound. The difference is the guard - what Sarge is showing in the picture makes leaving the blade at the full-height a very safe option - it'd be very difficult to get an appendage into the blade with that guard.
Some of us haven't been able to add an auxillary guard to replace out POS stock guard, and wind up not using the stock one because it interferes with normal operation of the saw. In this case, you'd probably want to minimize the exposure to the spining blade, so you lower it until the gullets between the teeth just clear the stock. Under these circumstances, kick-back danger is much increased, so one needs to use a good auxillary splitter and featherboards. It's hard to over-emphasize the need for these. Yes, they're a PITA to have to set and re-set for every cut, but they could literally save your life - I'm religious about using them.
Sarge, is the shield your own construction?
Negative on my own construction. Lee Styrone of Shark Guard does build his for that guard. This is a Penn State shield from the over-head guard system they sell. It is sold separately for $25. But... I do some modification on my smaller BS to the original box design to arc the front to allow stock to glide into and under it. On the Penn State system.... the shield is atttached to a adjustable mount and sits over the work never touching it.
Regards...
Sarge..
Edited 11/25/2008 3:22 pm ET by SARGEgrinder47
I tend to agree with Jigs and Sarge on this one. Although I do not do it all the time. I however do it on my nasty hardwoods.
I 'think' I can feel more 'pushback?' Is that a word? when doing what the recommended is. Using the recommended method on some sticks seems like the stick wants to lift...
No expert on the subject though.
I 'think' I can feel more 'pushback?
Yep... on thicker stock I know I can and unfortunately have had it lift on several occasions. That's when I started getting serious about finding ways to avoid that. Raised blade and proper hold-downs with a crown guard there just in case it does lift.
Thanks on the wheels... the good news is they are paid for at this point along with the drive-way they get parked in. With the current economy that is a good thing. :>)
Regards...
Sarge..
Oh boy... yes you are going to feel more "push back" and feel the stock want to rise as you feed it into the blade. That is ONLY if your blade is dull or the wrong blade. Put a good blade on your saw and you will NEVER feel that ever again! Really! I know from experience that a good blade is the cure of many problems (you don't have to spring for the most expensive) I cringe at the thought that someone would raise the blade to full height to cut some sheetgoods because there is less feed pressure felt, scary!
"Oh boy... yes you are going to feel more "push back" and feel the stock want to rise as you feed it into the blade. That is ONLY if your blade is dull or the wrong blade. Put a good blade on your saw and you will NEVER feel that ever again! Really! I know from experience that a good blade is the cure of many problems (you don't have to spring for the most expensive) I cringe at the thought that someone would raise the blade to full height to cut some sheetgoods because there is less feed pressure felt, scary"!.... chocolatehills
***
Am going to adamantly disagree with the statements ONLY and NEVER here chocolatehills. Those are pretty definite words that appear to make all situations final. A good blade is a must but regardless of how good it is it must be sharp. And yes.. it will cure many problems but.. not all of them I can assure you.
And no.. you don't need to have a blade at full height to cut a sheet of ply. 3/4" ply is not bad but... if you have ever had a sheet of 1/4" rise and twist off a low blade... then kick you hard in the gut as it tries to escape... you realize that having no blade guard and low blades aren't necessarily the best approach. The issue is not feed pressure in this case but the low weight and flexibility of thin ply has a hard time keeping it down on the table from gravity. Combine that with a shallow attack angle from a low blade and you have a kick-back waiting to arrive on the scene. And why cringe when the blade is raised and properly covered?
***
"Oh, just one other thing. With a powerful cabinet saw and a good saw blade (like a forrest ww2) there are no "nasty hardwoods" the saw will cut anything just like butter, no problem, no pushing, easy. Something to think about. I routinely cut 2" oak with my PM66 and a good blade, I don't feel any resistance at all".. chocolatehills
***
Again I am going to disagree and I think that there are many experienced WW's that would also. "There are no "nasty hardwoods" when using a good blade and a powerful cabinet saw. The saw will cut anything just like butter"
I have a 5 HP cabinet saw. I have 4 rip blades.. two Amana 20 T and two CMT 24 T all with proper gullet to remove waste and they are sharp. I rotate blades when doing a big job and always have one at my sharpener a few miles away with a two day turn-a-round. But.. I just got through ripping 2000 linear feet of hickory for hire ranging from 1" to 4" thick.
I can assure you that having a powerful TS and a good, sharp blade does not always elate to like cutting butter. Those along with proper TS alignment go a long way.. but are not a Holy Grail by any means. When you rip 8' -14' lengths and run into too much hidden moisture or trouble grain.. it's simply not the case. How much black locust or lignum vitae have you ever dealt with?
Not trying to be controversial here but... you need to think through what you state as most here are probably more experienced than you might give them credit for it appears.
Sarge..
Sarge.. I was not going to comment further but you did and when I typed feel the push-back was improper. My saw is Ok but far from perfect and expensive. My blades are always sharp.
Maybe 'I can feel the board lift a bit' would have been more appropriate words to use.
Without hold-downs I've had em lift.. when encountering wet pockets in thick stock or tension from wild grain being released by the sever... I've had em push back. So.. strickly my experiences but I feel lift and push might be appropriate depending on what was encountered which was hopefully nothing. But.. never encountering either if you do a volume of stock is not really a reality IMO.
A sharp blade is very important to me Will. I had rather have a cheap blade with the proper tooth count for a given task that is sharp than the most high tech blade on the market which is dull or marginally dull.
I'll go watch some pig-skin now or take a nap... whichever comes first.
Regards...
Sarge..
Edited 11/25/2008 8:48 pm ET by SARGEgrinder47
Hi Sarge, tr a #### rip blade. I have a 24 tooth that I bought really by accident but the first cut was a revellation. I should have emphasized the blades more. I never feel push-up anymore (but I have in the past and I remember well the tendency to want to raise the blade. With the blade raised all the way, the teeth force the piece into the saw table but the saw is raised way to high for safety.
Another thing that a good tablesaw will probably do in reducing the force felt when pushing the stock through the blade is the run out or wobble. I am not sure how much effect this has but it must be some. I don't want to be seen as a tool snob but good tools do make a difference. I bought my PM66 used from craigslist and the difference from even a unisaw was considerable in my opinion. I still consider the blade to be the most important part however. I have a whole stack of TS blades that just sit there because I don't want to use them, waah!
Thanks for the clarification. But.. I still am not sure you're grabbing my concept with having the blade raised with your statement:
"With the blade raised all the way, the teeth force the piece into the saw table but the saw is raised way to high for safety"... c h
Again I am going to post a picture of the way my saw blade is used. I am not sure how it would be deemed unsafe to raise the blade using this method? If I have missed something that could cause me injury... please point it out. And do notice those "red-lines" on my saw. My hand never gets closer to the shield and blade than that. They are my cue to pick up the one of the custom push sticks I make as they get the call from that point forward.
I won't lean over a blade either as that can be avoided by thinking through the operation before you turn the saw on. And the lane must be kept clear while the blade is spinning. There is a hole in my sheet-rock wall from years ago about 20 feet from the TS that taught me that stock can be launched at a pretty rapid rate in kick-back to the front. I left that hole open just as a reminder just as the red lines are there.
I am very aware that many (most probably until recently) take off the shields.. splitter.. and run their hands dangerously close to an open blade. If one insist (as it is their right to do whatever they please) then a low blade would be best.. or spend an extra $1500 for a blade brake machine.
In other words... create a problem that didn't necessarily exist before the fact and then fix it after the fact. In the words of those Guinness guys... Brilliant! :>)
Regards...
Sarge..
Edited 11/26/2008 11:20 am ET by SARGEgrinder47
Hey Sarge, I think that I first made a mistake in that I didn't read the whole thread, so I just jumped in without a complete knowledge of the topic as it was being discussed.
I have to admit also, that the set-up in your table saw is inherently safer than mine. I have already admitted to having purposely defeated the safety measures on my saw (the saw guard and splitter) I have always done so but that doesn't mean it is the right way to go. TS are getting safer and those safety issues are getting more user friendly so maybe in the near future, no one will take them off, I welcome the day.
Anyway, good blades are also a safety feature. This is one safety feature that doesn't get in the way of your field of view or make things harder to do but just costs some money or a little extra time to change the blades. I hear you when you say that you keep your blades sharp and change them according to use but I see all the time that some people don't. That is a mistake and when I hear people wondering why their stock was rising as it was being fed into the blade, I feel that is a dangerous situation. I have been there before and it is unnecessary as well.
Anyway, please accept my appologies for jumping into a thread when I had not really read the whole thing, that was uncalled for and ignorant on my part...
Peace, brother...I still have fingers enough to sign. ;)
No apology necessary, CH. Just a matter of opinions on a forum and sorting out what is and what isn't. I have been fooling with this stuff for 38 years and have reversed my opinion many times as I either mis-understood or I assumed something that should have been more carefully thought out. To err is human and we all do it whether we will admit it or not.
You are correct that most take off the stock guard and splitter which is everyone's right to do so. In-convenient... gets in the way.. poor design.. just to lazy.. takes too much time which is nil compared to posting on forums every day..whatever. But.. the fact is when you do it and for whatever reason you do it you are waiving a chance of stopping an accident before it happens.
Just a matter of interpretting the bottom line... we can take off the safety features and just complain that the manufacturer should add one's that are instantaneous at no additional expense.. we can modify the one's that are there with a small amount of time and investment.. we can purchase aftermarket that someone does it for you.. or we have available now improvements on the saw from the factory but we have to dig deep in our pockets to get them.
Freedom of choice.... ain't life Grand? :>) ha.. ha... ha..ha..ha..
Regards...
Sarge..
Morning Sarge,
Any thoughts on making a riving knife for an old Unisaw? Or do you think I'd be better off getting a Merlin splitter instead?
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
I can only tell you how to upgrade a splitter, Bob. That's all I did with my Uni-saw when I had it and I was happy with that. I did purchase a splitter blank from Lee Styrone that makes Shark Guard over in Mobile, Alabama. He machines them thicker than a stock splitter and sets up the base for quick release. He also adds a dust shield and pawls but I only wanted the machined splitter itself to add a crown guard and my own dust cover.
But... I do believe there is a gentlemen that has just come up with an after-market riving knife for the Grizzly 1023. And if not mistaken he is working on one for the Uni-saw or someone adapted the Grizzly to the Uni-saw as the configuration down there is similar.
You might open a thread to that affect or someone might see this post and provide more information. It takes some machining to modify as he did to get the Griz knife... I'm really not interested in building any after-market riving knives as I am just too busy. At least not at this point and you never know what tomorrow may bring.
Regards...
Sarge..
Sarge,
I just ran the information down about the person who developed the aftermarket "bolt-on riving knife," or "BORK" for the Grizzly 1023. It also, aparently, adapts for use with a Delta Unisaw. The maker's name (I think) is Bob Ross, and here's the link..
http://shop.walnutacrewoodworking.com/product.sc?categoryId=1&productId=6
It looks like a reasonable solution. However, it does require manual adjustment of the knife as you raise or lower the blade. That wouldn't be too much of a deterrent for those, like yourself, who don't move the blade height much. And one of the good things is that the knife does tilt with the blade, so it can be used on bevel cuts as well.
The price is $125.00. I'm not affiliated with this product in any way, but thought others might find it interesting to explore.
Zolton If you see a possum running around in here, kill it. It's not a pet. - Jackie Moon
Here's another discussion about the BORK, with more photos..
http://familywoodworking.org/forums/showthread.php?t=11288If you see a possum running around in here, kill it. It's not a pet. - Jackie Moon
Thanks Zolton.. You are correct as I have seen and heard the scuttle on several web-sites. I thought I had read someone did use one on a Uni on another forum. Again.. this is for Bob as I am content with my current set-up on the Steel City 5 HP. Works for me as I mainly rip at 90 degrees and with blade raised... I'm not giving up that much with my additional add-ons.
Regards...
Sarge..
Hey, they seemed to have xxed out #### which is a japanese blade manufacturer..hmmm. anyway about:
And no.. you don't need to have a blade at full height to cut a sheet of ply. 3/4" ply is not bad but... if you have ever had a sheet of 1/4" rise and twist off a low blade... then kick you hard in the gut as it tries to escape... you realize that having no blade guard and low blades aren't necessarily the best approach. The issue is not feed pressure in this case but the low weight and flexibility of thin ply has a hard time keeping it down on the table from gravity. Combine that with a shallow attack angle from a low blade and you have a kick-back waiting to arrive on the scene. And why cringe when the blade is raised and properly covered?
I have to say that has happened to me in almost the same way (thin plywood is one occasion that I lift the saw blade higher than usual. and... I am coming from the point of view of an old-timer in that I have always removed my saw guards. I wish I had a riving knife but don't want to trade in my saw. Maybe from that perspective you can understand my "cringing" ! If the blade is well covered and the splitter in use, that's safe enough in my opinion. I know however that there are a lot of TS accidents every year and a friend of mine recently almost lost a few fingers. He laughed at me when I was critical of his TS practices before but not now.
Oh, just one other thing. With a powerful cabinet saw and a good saw blade (like a forrest ww2) there are no "nasty hardwoods" the saw will cut anything just like butter, no problem, no pushing, easy. Something to think about. I routinely cut 2" oak with my PM66 and a good blade, I don't feel any resistance at all. There is a price to pay but it's certainly worth it considering the price of health care and emergency room visits etc...That said, I started out with a Craftsman TS that had a steel blade, I remember the wood wanting to "rise up" as I pushed it through the blade. Wow I still have my fingers!
In continuing this discussion with riving knives, I emailed customer service at Grizzly to see if they're planning on retrofitting a riving knife to their existing 1023 tablesaws. Here's the answer I received...
"Dear Zolton,<!----><!----><!---->
<!----><!---->
Thank you for your email dated November 23, 2008.<!----><!---->
<!----><!---->
We appreciate you contacting us regarding your G1023SLW 10” Cabinet Table Saw with Router Table Extension. Unfortunately, at this time, we have no plans on releasing a riving knife option for our G1023 Series of Tables Saws. Please check our new catalogs, when released, for updates on this possibility. <!----><!---->
<!----><!---->
If we may be of further assistance, please do not hesitate to contact us. You are a valued customer and we look forward to serving your future woodworking and metalworking needs.<!----><!---->
Sincerely,<!----><!---->
Vince<!----><!---->
Technical Service<!----><!---->
Grizzly Industrial, Inc.<!----><!---->
EN #901
So, it looks as though they don't plan at this time to produce a retrofit riving knife. However, "Vince" left open the possibility that they might in the future. I wonder if Vince is in politics...
At any rate, in looking at the trunnion assembly, it doesn't seem to me as though it would be all that difficult to make something that would work. Of course I'm no engineer. But according to Vince, I am a valued customer. Which, I admit, does make me a bit proud. In the meantime my fonts are going haywire!
ZoltonIf you see a possum running around in here, kill it. It's not a pet. - Jackie Moon
I vote for the "high" blade - IF you have the proper guarding. I purchased a Shark Guard (not as pretty as Sarge's setup, but it works.) You can see the clearance between blade and splitter decreases with hight.
Frosty
"I sometimes think we consider the good fortune of the early bird and overlook the bad fortune of the early worm." FDR - 1922
The Shark Guard by Lee Styrone is probably the state of the art when it comes to after-market splitters. Lee does excellent work in both design and with his metal-work. He built me a custom splitter for my Uni-saw that I added my ingredients to the top of. Excellent machine work.
And... I intend to do a template for my Steel City 5 HP with the blade fully raised that is very close to the blade as a riving knife and curve over the top. I will add a crown guard and quick release myself but the call for the custom splitter goes out to Lee as he is the man that can do it and do it right the first time.
Regards...
Sarge..
Sarge,You often refer to a "crown guard". Is that the piece of wood that rests on the top of the blade? If not, what?Frosty"I sometimes think we consider the good fortune of the early bird and overlook the bad fortune of the early worm." FDR - 1922
That is correct, Dusty. Crown means top or close without going to Webster's book. It is simply a piece of hard-wood in this case bolted to the top of the splitter to stop stock from launching straight up. A riving knife or splitter keeps wood from touching the rear teeth. But.. once kick-back has started the stock can launch left.. right.. up.. forward depending on just what ingredients led to kick-back.
A crown can be made from wood.. plastic.. phonolic.. metal... etc. It just has to be strong enough to not come apart on high impact. And it is no better than the method used to anchor it to the splitter or riving knive. Whatever that method is must be strong also.
BTW.... I have a new crown I just built yesterday. I moved the dust port forward and made a longer crown that completely covers the top of the blade now. As soon as the red paint dries... she'll be on the TS.
Regards...
Sarge..
Edited 11/25/2008 3:23 pm ET by SARGEgrinder47
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