Resaw Problem

[Tim Bridge]

I am trying to resaw some walnut veneer and I am getting some thickness variation.
The board is 6" wide and 12" long.
I have resawed next to the fence (inside) and outside the blade with the same result.

On the leading edge into the blade I get .016" and the trailing edge is .026"
From top to bottom I get a variation of .003"

The top to bottom variation is a squareness adjustment but .003" is not bad.

I can't tell if the variation I am getting between leading and trailing ends is due to the way I am feeding the board or an adjustment.

Is this an adjustment I could make to fix or human error?

[Scott DelPorte]

Hi Tim
Are you accounting for drift angle when you cut? Assuming your blade is tensioned correctly and sharp, you can sometimes compensate by adjusting the fence angle a little "off square" if the cut is drifting consistantly to one side.

Scott

[Erik Loza]

What machine and what blade?

Erik

[Al Launier]

Hi Tim
Are you accounting for drift angle when you cut? Assuming your blade is tensioned correctly and sharp, you can sometimes compensate by adjusting the fence angle a little "off square" if the cut is drifting consistantly to one side.

Scott

My thoughts exactly.

[glenn bradley]

What machine and what blade?

Erik

I'll wait for this as well. I am assuming you are re-surfaceing the sawn surface before each additional pass(?). I do this by jointing a face, jointing an edge and planing to thickness . . . cut off a piece of veneer, replane, cut off a piece of veneer, replane, etc.

[Tim Bridge]

It's a 1999 Laguna LT 16 Italian fitted with ceramic guides with a 1-1/4" Resaw King blade and a Driftmaster fence.

[Tim Bridge]

I haven't replaned after each cut. It's a good idea.
I adjusted for drift by centering the blade in the cut as Laguna recommended. Is there a better way to get this more accurate?

[Scott DelPorte]

You mention .010 variation in a foot. If it is consistent, you can try to adjust the fence and see if you can remove it. I adjust my fence for drift just using a trial and error method. I just make small drift adjustments until I can cut consistent slices and then cut to the outside of the blade so I am only jointing once. If you move the fence for each cut and cut from the outside (like on a meat slicer), some of the error from your cuts on either side of the piece (top to bottom variation) will cancel out and you should get more even thickness on each piece compared to always cutting from the inside. At least that has been my experience cutting thin stuff.

The only other thing I can think of that you might want to check while you are at it is your blade tension. I'm not familiar with that particular saw and whether it can fully tension an 1 1/4 blade (I assume it can), but I go off a gauge that measures actual blade stretch rather than the little indicator on the saw.

[David Kumm]

If the saw is the regular ACM 16" and not a heavier resaw machine, the 1.25" RK probably can not tension enough. I had an LT 18 and even with an upgraded spring, I doubt it would tension that blade. I used a 1/2" Trimaster as even the 3/4" was running at low tension. You can resaw and get acceptable results with a carbide blade at 10,000 lbs but all the planets need to line up. A 3/4" RK is as big as I would go on that saw. The RK has a thin band so it tensions easier but will also wander more under low tension and the stress of a too fast cut. Dave

[Scott DelPorte]

As a reference, I will usually tension the blade between 25,000 and 27,500 psi, which is toward the low end of the "green zone" on my gauge.

[John TenEyck]

What David said. Drift is usually caused by one of few things: a blade with too low tension, a dull blade or one with uneven set, or the blade isn't adjusted properly on the wheels and is steering left of right. Adjusting for drift means something is wrong; find it and fix it and your saw will cut straight and parallel with the miter slots. Only then is a BS truly useful, at least in my world.

It sounds like your saw cannot adequately tension the blade you are using. By adequate tension I mean 25,000 psi. But before you buy another one, have you tried adjusting it on the wheels? If it wants to cut left move it further back on the upper wheel, further forward if it steers right. Rip some scrap until it cuts dead straight, then try taking another slice of veneer, using light, steady pressure. Be sure to start with flat stock with a squared edge, and that your fence is truly parallel with the blade.

John

[John K Jordan]

After I got a Starrett bandsaw blade tension gauge I quit using blades over 3/4" - my 18" Rikon simply couldn't tension them properly without what I felt was too much force and stress on the components.

JKJ

[Tim Bridge]

The nameplate on the saw says it is rated for an 1-1/4" blade. When I use the tension gauge on the saw, and set it for an 1-1/4" blade it maxes out.

From what some of you are saying the saw blade max size may be exaggerated and I should use a narrower blade.
If the tension gauge on the saw isn't very accurate what should I use?

[David Kumm]

Tension gauges on a saw are only a reference for setting the tension close to what you have determined as the best for each blade. The graduations really don't relate to much. For the gauge to read what is really appropriate for a certain size blade, it would need to know the recommendation for that blade, or at least the thickness of the band itself. Saws usually allow for wider blades than they can tension. They use the width of the wheels as the determining factor. I use a Starrett or Lenox gauge because each saw and blade has it's own sweet spot and I'm not bright enough or musical enough to do it by feel or ear. Dave

[Andrew Hughes]

Bad resawing always points back to a blade getting dull or dull.New blades cut fast and straight.
I really wish bandsaw blades would last longer.
The truth for me is I try to use one blade for everything and it doesn't take much to spoil the tips.
Ive not found tensioning to make that much of a difference.