Re-sawing on the bandsaw
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Re-sawing on the bandsaw
I have a updated SS band saw and I am trying to re-saw a 6" thick piece of green red oak. Each time I try it I am getting a curve in the cut. Am I feeding the wood to fast? Is it a setup problem? I have a 1/2 blade and am using the rip fence. Thanks
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scottss
- Gold Member
- Posts: 301
- Joined: Mon Aug 14, 2006 10:46 am
- Location: Pacific Northwest Washington State
I have resawed oak many times and what I have found is you must go slow. I resaw 6" pieces all the time and come out with very true straight cuts. Make sure your saw table is set for a 0 degree cut, I mean you need to check it with a square. My table was off at first. I use my fence but you could attach a 1"x 6" dowel to a board and clamp it to the fence.
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dusty
- Platinum Member
- Posts: 21374
- Joined: Wed Nov 22, 2006 6:52 am
- Location: Tucson (Wildcat Country), Arizona
Resawing on the Bandsaw
This subject has come up multiple times recently. The fence not being square to the blade has nothing to do with this symptom. Bandsaw drift is a function of the blade that you are using. It is rare to find a bandsaw blade that will not result in some drift.
As a requisite to analyzing this problem you should make sure that the tension on the blade is correct and that all of the follower bearing adjustments are correct. Inspect the tire and clean it if necessary and as for tracking on the tire -- i am not going to comment except to say that mine has never tracked in the center of the tire. I don't believe that SS Bandsaws do normally track in the center.
http://www.shopsmith.net/forums/showthread.htm?t=241
I have another article somewhere that explains bandsaw drift very well and gives detailed instructions on how to compensate. In the meantime, follow the instructions in the post listed above and I believe you will be resawing with great success.
I found it: http://www.shopsmith.net/forums/showthr ... ight=drift
As a requisite to analyzing this problem you should make sure that the tension on the blade is correct and that all of the follower bearing adjustments are correct. Inspect the tire and clean it if necessary and as for tracking on the tire -- i am not going to comment except to say that mine has never tracked in the center of the tire. I don't believe that SS Bandsaws do normally track in the center.
http://www.shopsmith.net/forums/showthread.htm?t=241
I have another article somewhere that explains bandsaw drift very well and gives detailed instructions on how to compensate. In the meantime, follow the instructions in the post listed above and I believe you will be resawing with great success.
I found it: http://www.shopsmith.net/forums/showthr ... ight=drift
Hi,
Noticed the word "green" wood. I don't have a shopsmith bandsaw but I have cut green wood... not sure if I ever did oak but green wood seems to have its own issues.... In fact I have even seen bandsaw blades for cutting green wood...... not sure if they are shopsmith size??
Take a look at:
http://www.highlandwoodworking.com/inde ... rodID=6944
I have never used the blade but it had caught my interest when I saw it in the catalog. Perhaps someone here has one and can comment.
Ed
Noticed the word "green" wood. I don't have a shopsmith bandsaw but I have cut green wood... not sure if I ever did oak but green wood seems to have its own issues.... In fact I have even seen bandsaw blades for cutting green wood...... not sure if they are shopsmith size??
Take a look at:
http://www.highlandwoodworking.com/inde ... rodID=6944
I have never used the blade but it had caught my interest when I saw it in the catalog. Perhaps someone here has one and can comment.
Ed
They list the blade in 72" length. That is the SS size.reible wrote:Hi,
Noticed the word "green" wood. I don't have a shopsmith bandsaw but I have cut green wood... not sure if I ever did oak but green wood seems to have its own issues.... In fact I have even seen bandsaw blades for cutting green wood...... not sure if they are shopsmith size??
Take a look at:
http://www.highlandwoodworking.com/inde ... rodID=6944
I have never used the blade but it had caught my interest when I saw it in the catalog. Perhaps someone here has one and can comment.
Ed
John & Mary Burger
Eagle's Lair Woodshop
Hooper, UT
Eagle's Lair Woodshop
Hooper, UT
There are several things you can do to prevent cupping when resawing:
1. Use the largest blade available to you. The wider, thicker, and stiffer the blade is, the less likely it is to cup in the cut.
2. Increase the blade tension. You can safely go a notch or two (or even three) past the indicator marks on the tensioning spring. Some bi-mateal blades will withstand many times the recommended tension for ordinary steel blades. The extra tension keeps the blade taut in the cut and helps prevent cupping.
3. Use skip-tooth blades. When cutting through a thick board (or cutting through the width of a board), each tooth is buried in the cut for a long time, raking the wood and cutting away long slivvers. These slivvers lodge in the gullets between the teeth and then are thrown free when the teeth exit the cut. If the cut is too aggresive or the stock is too thick, the slivvers will pack in the the gullets, press against the sides of the kerf, and slow the blade down in the cut. At this point, the tension is not the same along the length of the blade. It's higher where it exits the cut than where it enters it. In effect, the band saw is feeding the blade into the wood faster than it can pull it out. The blade goes slack in the cut and cups. A skip-tooth blade has wider gullets, more room for slivvers, and is less likely to cup in thick stock.
4. Finally, you can use a variable-pitch blade. This is a blade that was originally developed for the meat-packing industry, but it works like a champ for resawing. Ordinary blades have evenly-spaced teeth (a consistent pitch) and they beat out a rhythm as they contact the wood upon entering the cut. Because the blade in under tension, the rhythmic pattern of the teeth scraping the wood produces a harmonic in the blade and it begins swinging back and forth. This is the condition you see in a blade right before it cups.
A variable-pitch blade won't create a consistent rhythm, it is less likely that the blade will produce a harmonic vibration, and it rarely enters the requisite precondition for cupping. You can puchase a 5/8" variable-pitch blade for the Shopsmith band saw, see http://www.shopsmith.com/ownersite/cata ... blades.htm. It's a great blade; I've used it to cut 1/16"-thick veneers from curly cherry and figured maple.
With all good wishes,
1. Use the largest blade available to you. The wider, thicker, and stiffer the blade is, the less likely it is to cup in the cut.
2. Increase the blade tension. You can safely go a notch or two (or even three) past the indicator marks on the tensioning spring. Some bi-mateal blades will withstand many times the recommended tension for ordinary steel blades. The extra tension keeps the blade taut in the cut and helps prevent cupping.
3. Use skip-tooth blades. When cutting through a thick board (or cutting through the width of a board), each tooth is buried in the cut for a long time, raking the wood and cutting away long slivvers. These slivvers lodge in the gullets between the teeth and then are thrown free when the teeth exit the cut. If the cut is too aggresive or the stock is too thick, the slivvers will pack in the the gullets, press against the sides of the kerf, and slow the blade down in the cut. At this point, the tension is not the same along the length of the blade. It's higher where it exits the cut than where it enters it. In effect, the band saw is feeding the blade into the wood faster than it can pull it out. The blade goes slack in the cut and cups. A skip-tooth blade has wider gullets, more room for slivvers, and is less likely to cup in thick stock.
4. Finally, you can use a variable-pitch blade. This is a blade that was originally developed for the meat-packing industry, but it works like a champ for resawing. Ordinary blades have evenly-spaced teeth (a consistent pitch) and they beat out a rhythm as they contact the wood upon entering the cut. Because the blade in under tension, the rhythmic pattern of the teeth scraping the wood produces a harmonic in the blade and it begins swinging back and forth. This is the condition you see in a blade right before it cups.
A variable-pitch blade won't create a consistent rhythm, it is less likely that the blade will produce a harmonic vibration, and it rarely enters the requisite precondition for cupping. You can puchase a 5/8" variable-pitch blade for the Shopsmith band saw, see http://www.shopsmith.com/ownersite/cata ... blades.htm. It's a great blade; I've used it to cut 1/16"-thick veneers from curly cherry and figured maple.
With all good wishes,
Nick Engler
http://www.workshopcompanion.com
http://www.workshopcompanion.com