Replies

1. 
   AlanWS | May 13, 2004 03:00am | #1

   A 7" diameter wheel is very small, so the band is more sharply bent than on a larger machine. This can cause the blades to break sooner. A metal cutting bandsaw has a much slower band speed than a wood cutting one, which may explain why your 1/2" blade can survive -- it's not bending back and forth quite so fast. If you do use it for wood, I suspect that speeding it up with a larger pulley would not be a good idea, since a 1/2" blade probably can't take it. That means you would need to feed the wood more slowly, but if that's the saw you have, it might do. A 3/4" blade is too big to last long on a 14" wheel bandsaw, though it is really the thickness of the blade that must be limited on a small wheel. I'd try a blade no wider than 1/2", and as thin as possible at first.

   You should be able to try it out, buying a good blade of any length you want. Here for instance:

   http://www.suffolkmachinery.com/

   Better yet, call them up and ask what they recommend.

1. 
   MBL | May 13, 2004 08:43am | #2

   Thanks, Alan.

   Your comments make sense.

   What about 6 TPI, is it OK for re-sawing? Have seen 3 TPI recommended. One vs. the other is a factor of 2 to 1.

   Would 3 vs. 6 TPI make a 2 to 1 difference in actual functioning?

   Doesn't re-sawing benefit from a slower blade speed?

   What is attractive about this type of metal saw is that it has a 1 piece cast-iron 'C' frame that is very rigid and seems to take blade tension and stresses very well. It seems like a good design for re-sawing applications.

   Wonder if anyone has used them as such.

   Thanks.

   -mbl-

2. 
   Curtis | May 13, 2004 12:05pm | #3

   Hello

   what you suggest is already made by Greenlee (an electrical supply co.) the upper carriage is locked into the up-right, and there can be a table added,very easily.

   you can adjust the pulleys to increase the speed of the sawblade.

   because the small wheels the saw will not take any blade larger than 1/2" blades. but I belive It may be worth the effort to try.

   Good luck.

   and let us know how it works.

   C.A.G.
3. 
   jackplane | May 13, 2004 03:57pm | #4

   Bad idea because on these machines you cannot adjust the guides, which results in blade wandering through the wood. If you can step up the motor speed that would help,but metal cutting bandsaw rpms are too slow to effectively resaw timber.

4. 
   DennisS | May 13, 2004 04:33pm | #5

   MBL -

   Blade speed and size aside, one thing I'd worry about is sawdust accumulation. If your saw is like mine and you've used any kind of recommended cutting lubricant, there's ample gunk about that would attract gobs of fine sawdust that might clog things up a bit. I have the Porter-Cable Portaband saw which seems to have a geared drive assembly. Thus it delivers more 'power' to the blade than its HP rating would suggest. I've never stalled it cutting metal so I'd suspect you could use as aggressive a blade as you'd like in wood without fear of overtaxing the motor.

   ...........

   From Beautiful Skagit Co. Wa.

   Dennis

1. 
   MBL | May 13, 2004 06:16pm | #6

   Friends,

   Thanks for the comments. Do appreciate them.

   Today, will go buy a blade, probably 1/2", hard-back carbon steel, 6 TPI sold for metal cutting at Grainger. Don't know yet if they cut and braze them.

   These additional observations seem to be in favor of the idea:

   1. The fact that the wheels are only 7" in diameter means that they have much less wobble than 14" wheels. That's because the larger a wheel, the more perimeter wobble, for similar applications.

   2. These metal bandsaws, TWIST the blade slightly at the guides. The guides are very strong and fixed as far as height is concerned to just a hair above 6". Because they are not adjustable, they can be built so much 'fixed' and strong. The guides do not use blocks but 3 bearings.

   3. Because the blade is twisted, the dust does not want to fall into the wheels. Plus a brush could easily be improvised, mounted to wipe the blade.

   4. Would say that for resawing alone, a bandsaw would not need to have a large throat capacity, which is a feature so desireable for our upright typical wood work.

   5. Larg wheels, say 14" dia. and over, introduce wobble, and tracking issues. Those wheels use rubber tires on which the blade runs. These metal bandsaws do not even use rubber tires. The blade rides directly over the wheels.

   *Stil would like to hear comments on 3 TPI vs 6 TPI in re-sawing*. Does a factor of 200% mean that much?

   With this aproach, the point is not to revolutionize anything, friends. The point is to make use of that which is already here, for modest resaw use.

   Will happily report back on any success or failure.

   Thanks to all.

   -mbl-

1. 
   Tao | May 13, 2004 06:37pm | #7

   Tooth count means a lot.  Even 3 TPI is a lot for resawing, but it will get the job done as long as the stock isn't too wide.  The dedicated band resaws I have seen appeared to have about 1 tooth per inch, and industrial band mills for resawing logs have about one tooth every 4 to 6 inches or so.

   When a tooth travels through 8 or 12 inches of wood, there has to be a very large gullet to hold the sawdust, otherwise the dust is forced out alongside the blade, leading to heating and poor tracking.  Plus there is the factor of thrust per tooth.  It takes twice as much force to get twice as many teeth to take a proper cut, and at 6 TPI, it takes a lot of force to keep a blade cutting in a deep cut, since you could have as many as 36 teeth in the cut at one time on a 6" board.

   Your comments about large wheels just don't stand up in practice.  In my experience, the bigger the saw, the sweeter it runs, and the beter it tracks.  I've never been able to get what I would call good performance on wood from anything under 14", and the difference when you step up to even a 20" is very distinct.

   The others' comments about blade speed are pretty much correct, too.  All in all, a band cutoff saw is just about everything you don't want for resawing.

   Michael R

1. 
   MBL | May 13, 2004 08:18pm | #8

   Dear Woodwiz,

   Thanks for the info on toot-count.

   Will get 6 tpi as it's what's available, and one of the last things might try is to grind off a few teeth if needed. 3 tpi seem to be available only for much wider blades. Will for this one limit to 1/2" wide.

   Probably 1 tpi is for real powerful machines with quite wide blades. The try here is for moderate use and a minimum of cost.

   -mbl-

1. 
   MBL | May 14, 2004 05:07am | #9

   Friends,

   Found today an industrial supplier (not Grainger) who cuts to length and had 4 TPI carbon 1/2" blade. They said that's what their clients buy to cut wood.

   They will have it ready for just a few pennys above ten dollars. First asked them to show me the stock, and they showed a Lenox roll.

   Thought it was quite reasonable. They guarantee for life the braze, and 3.00 if it breaks anywhere else. They service only the blades they've sold, though.

   It'll be ready next week.

   Well-being to all.

   -mbl-

2. 
   Tao | May 14, 2004 05:59am | #10

   It's clear that you are going tio have to find things out for yourself, and that's fine; I've been known follow my own ideas despite the advice of others, too.

   The final thing that you will find working against you will be blade speed.  I was looking up some other information today and checked the blade speed on a couple of horizontal band saws.  The typical speed was only 200 to 300 ft/min, while a typical 14" band saw runs at 3000 ft/min, and larger saws run around 5000 ft/min.  The consequence is that your saw is going to be   s  l  o  w.  Don't worry about it; it's just the wrong saw for the job.

   At least your idea isn't dangerous or expensive.  Have fun.

   Michael R.

3. 
   MBL | May 14, 2004 07:51am | #11

   Dear Woodwiz,

   What's to be resawn is modest. Pieces about 10" long. If it works for some 20" long or more, so be it.

   I did get a good pamphlet at the industrial place with a lot of information on the subject. They have all kinds of blades at this type of place. Even blades for cutting automotive tires. And they sell charts for coordinating blade speed, tpi, type of material, and so forth. They are like calculators.

   Even this 10.00 blade won't be wasted. Am looking ALREADY on how to make a bow-saw.

   Might even make a bow-saw, even if the h.bandsaw works OK. Already asked at the industrial supplier and they sell blade by the inch.

   Have not bothered to re-saw on bandsaw since the table saw can resaw up to 4.5" easily. But would like to waste less material, and to save some time and effort in changing blades. Plus resawing on a TS is less safe.

   Will check back on this next week after getting the blade. Could easily change pulleys too. Also, just found out that old Delta 8"

   bandsaws were pretty good re-sawers.

   Don't really have a problem, though. Please do not worry. Just wanted to know if anyone had done it.

   -mbl-

4. 
   MBL | May 21, 2004 07:40am | #12

   Friends,

   Got the 4 TPI for the horizontal metal bandsaw. Here's some details, if they may be of any interest.

   The blade was a little short, so couldn't fit it right in. As this saws twist the blade slightly so that when the arm swings down it cuts metal at right angles, removed the bearig guides and then the blade could fit-in, with no twist, i.e., straight.

   This unexpected event might have been serendipitous, since it is actually better, for cutting wood, that the blade don't be twisted.

   Built a small 1/4" mdfb 'table' about 8-square inches, and it did resaw ####scrap 2 x 4, slow, as expected. But the cut goes quite well, with good control, freehand.

   In order to improve, there would need to be a much more rigid table, probaly cast iron, which could be made from some scrap here. But probably will not go for that option, since have used the time since the blade was to be ready, to work on the vertical 14" wood bandsaw, and that is discussed in another thread.

   However, will also mention the following:

   1. The metal bandsaw guides are excellent and they are adjustable as to the squeeze unto the blade, and also as to the back support, and slightly as to the twist-set they are meant to provide.

   2. There is also a tracking mechanism that is much simpler that the 14" bandsaw, and also more effective, but for much shorter distances of adjustment.

   3. This saws with the 4 tpi blade run awful steady, compared to wooden saws. They are also very rigid and provided a lot of tension so that the blade feels like a solid knife.

   4. The saw is actually equipped with speed change pulleys. But the speed, of course, does not get anywhere near wood-cutting saws speeds.

   5. To really turn it into a wood slicer, it would not only require new pulleys, but also a larger motor, to cope with the higher speed and increaded hp requirement. While all that is feasible, will not opt into it, since the plan is to use the 14" bandsaw, revamped.

   6. However, the metal bandsaw can re-saw up to 10", specially with the bearing guides removed. Since the metal wheels are tapered and have a back-stop for the blade, they provide good back support, and for guides, very little would be needed. So some simple metal guides would be easy to adapt, consisting of just a soft metal with a slight cut. For free-hand use, though, no guides are needed. So, the plan is to use it for free-hand cutting, without guides.

   7. Because the saw runs at low speed with practically no wander nor vibrations, even on these preliminary tests, it will be an excellent device for cutting things such as cabriole legs. Did make many freehand quick turn cuts into the 2x4 and it just feels like using a scroll-saw. VERY precise curve cutting can be made with the setup and it is quite powerful for such slow use and that will DEFINITELY be an application for this item.

   Am passing along these findings, for interest, or as they may be of use for someone.

   Thanks for all suggestions given, none being contradicted.

   -mbl-