Bandsaw Drift

dusty · Post by **dusty** » Sun Sep 16, 2012 8:51 am

A function of the blade??

If bandsaw drift is caused by characteristics of the resaw blade, is it reasonable to assume that the drift will be the same for whatever piece of wood is being cut?

Gene Howe · Post by **Gene Howe** » Sun Sep 16, 2012 9:47 am

That's true Dusty. The drift will still be there. The angle may change a bit, though. Also, the angle changes with thickness, even in the same wood. i.e. flat sawing vs resawing.

dusty · Post by **dusty** » Sun Sep 16, 2012 9:58 am

Gene Howe wrote:That's true Dusty. The drift will still be there. The angle may change a bit, though. Also, the angle changes with thickness, even in the same wood. i.e. flat sawing vs resawing.

I find it interesting that I have had a bandsaw for so many years and that even though I use it on a very regular basis, there is so much left to learn about it and about me and what I don't know.

I have cut up a bundle of wood this morning just resawing small pieces into even smaller pieces.

The one thing that I have learned is that feed rate makes a difference in appearance but does not change the drift and it does not correct the roughness that started this whole expedition.

I do apologize to those of you who successfully resaw on a regular basis. This is truly a do nothing thread for you. I, on the other hand, am likely to learn a lot.

Gene Howe · Post by **Gene Howe** » Sun Sep 16, 2012 10:29 am

If you've corrected for the drift, then it sounds like an out of line tooth.... maybe a kinked blade? At any rate, I'd try a new blade.
Hey, I've been trying to get better cuts for 35 years. Still have to sand out blade marks.

marcp1956 · Post by **marcp1956** » Sun Sep 16, 2012 12:18 pm

I thought I knew a bit about woodworking. Far from an expert, but not a complete novice. After reading a few threads on this forum I find I have much to learn. I seldom even understand all the terms used. While I know what the word drift means, I have never considered the drift of a bandsaw blade. Resaw does mean cutting with the grain of the wood doesn't it? And what is flat sawing? Is this against the grain?

dusty · Post by **dusty** » Sun Sep 16, 2012 12:33 pm

marcp1956 wrote:I thought I knew a bit about woodworking. Far from an expert, but not a complete novice. After reading a few threads on this forum I find I have much to learn. I seldom even understand all the terms used. While I know what the word drift means, I have never considered the drift of a bandsaw blade. Resaw does mean cutting with the grain of the wood doesn't it? And what is flat sawing? Is this against the grain?

Flat sawing is not done in the shop. It is done typically in a milling environment. The item being cut being a tree.

Resawing to me is a redimensioning procedure where, for example, a 1"x6" board is cut into two 6" boards each less than 1" thick.

saminmn · Post by **saminmn** » Sun Sep 16, 2012 12:40 pm

Hi Marc,

Drift is the tendency of the blade to cut a little faster on one side than another, if i understand it correctly. If you mark a line parallel to an edge and then cut down that line you may find that your work piece does not stay parallel to the blade/miter tracks. That is caused by drift. So if you use a fence it will need to be adjusted to the drift or you will be fighting the drift instead of working with it.

Think of re-sawing as cutting a slice off a board. On an SS band saw you can create a board say an 1/8" thick by about 6" wide, just run a 1x6 lengthwise keeping one face parallel to the blade. Lay the board down and do flat sawing with the grain or curving around a pattern, etc.

I am a newbie and if this needs a better explanation someone will jump in.

saminmn · Post by **saminmn** » Sun Sep 16, 2012 12:43 pm

dusty wrote:Flat sawing is not done in the shop. It is done typically in a milling environment. The item being cut being a tree.

Resawing to me is a redimensioning procedure where, for example, a 1"x6" board is cut into two 6" boards each less than 1" thick.

See even before I posted someone is setting you straight:) Believe him on flat sawing.

backhertz · Post by **backhertz** » Sun Sep 16, 2012 3:32 pm

A Carter bandsaw set up video.
http://www.youtube.com/watch?v=wGbZqWac0jU

At the 6 minute point, co-planer wheels are addressed. I learned from Shopsmith technical support that the Shopsmith bandsaw wheels are indeed co-planer. So what he says about there being slight angles on the wheels doesn't apply to the Shopsmith.

At 9:20 he makes an adjustment to help in resawing- is this true with the Shopsmith?- I don't know, but he says it will result in perfect resaw.

He maintains there should NEVER be drift on a bandsaw. Well, I'm not sure what he says applies to a Shopsmith bandsaw. To my knowledge, a Shopsmith does have drift and the fence is adjusted accordingly to compensate for blade drift.

dusty · Post by **dusty** » Sun Sep 16, 2012 4:33 pm

backhertz wrote:A Carter bandsaw set up video.
http://www.youtube.com/watch?v=wGbZqWac0jU

At the 6 minute point, co-planer wheels are addressed. I learned from Shopsmith technical support that the Shopsmith bandsaw wheels are indeed co-planer. So what he says about there being slight angles on the wheels doesn't apply to the Shopsmith.

At 9:20 he makes an adjustment to help in resawing- is this true with the Shopsmith?- I don't know, but he says it will result in perfect resaw.

He maintains there should NEVER be drift on a bandsaw. Well, I'm not sure what he says applies to a Shopsmith bandsaw. To my knowledge, a Shopsmith does have drift and the fence is adjusted accordingly to compensate for blade drift.

This is an impressive presentation and everything that he says may be true when working with a Powermatic bandsaw and Carter Guides.

Co-Planar: He says that all bandsaw wheels are suppose to be co-planar and that if they are not the blade will walk right off the blade.

The primary purpose of the lower guide bearings on the Shopsmith band saw is to prevent the blade from walking off the back of the wheels. This bearing is needed because without that bearing the non-coplanar wheels WILL walk the blade off the back.

The blade is suppose to be backed up against that bearing at all times. Unlike in this demo, the lower backup bearing should be spinning when the wheels are turning.

The Shopsmith band saw is not like the others in this regard.

I don't have Carter guides. I would sure like to here from some of you who do. Are you able to adjust your Shopsmith bandsaw consistent with what is in this demo.

Maybe we also need a discussion about what it means for the wheels to be co-planar. I think it means that both wheels should run in the same plane.

Go put a straight edge across your Shopsmith upper wheel and see if it aligns with and touches both the top and bottom edge of the lower wheel.

Please - DO NOT attempt to make them co-planar.

To see this for yourselves (anyone who believes they are co-planar), pull the cover off of the bandsaw, tilt the table to get it out of the way and place a straight edge against the ends of the two wheel spindles. Measure the distance from the edge of that straight edge to the upper edge of the upper wheel and the lower edge of the lower wheel. There will be a difference of approximately 1/8"; the upper wheel being canted back.