Thread: Bandsaw blade twists while cutting

I have posted the AWR article below by Peter Young which claims that you can align the blade to be parallel to the mitre slot by using the tracking knob. Sadly, I have been unable to do this

Blade drift - myth -AWR.pdf

Dengy, loosen the table fixing bolts and align the table to the blade as suggested above. Loosening the bolts should give enough movement of the table to align it and won't create other issues at all.

Originally Posted by Chris Parks

Dengy, loosen the table fixing bolts and align the table to the blade as suggested.

Yes, this will be the next step, thanks Chris. But it still does not solve the basic problem with the ceramic guides. The guides, which are horizontal pieces of ceramic with a square cross-section, will not be parallel with the blade if the blade is twisted, and will not work properly.

But I will be contacting Cameron Ward at Gregory Machinery before I do that. He is the recognised expert on Laguna bandsaws, and I will be interested in what he says about the blade being at an angle to the mitre slot.

I will be contacting Cameron Ward at Gregory Machinery

You are correct, Chris Parks. Many thanks for all your comments and support, very much appreciated.

After reading my email summarising the situation, and looking the latest photos I attached, Cameron also considers the table is twisted, and is contacting the manufacturer to determine the best way to fix the problem. Hopefully it will be a simple method. That table is quite heavy.

this twisting has occurred over time, but not sure how. I do pull the bandsaw around the workshop by hand using the table, but the bandsaw is mounted in a frame with 4 large castor wheels, and can easily be manoeuvred by one hand.

Incidentally, Cameron agrees that the blade should be able to be made parallel to the mitre slot by adjusting the tracking knob. With the Laguna 14-12, he has never experienced blade drift with the 3/4" blade centred on the tyres,

Originally Posted by woodPixel

Too much tension.

I have the same problem with my Laguna SUV14 using the RSK and Lenox WoodMaster CT blades (LWM from Henry Bros, its excellent).

When I use the full power of the tensioner, I get exactly as you describe. Dial it back a bit and the problem disappears. It doesn't NEED masses of tension... not at all.

Also, with the rear ceramic, I don't let it touch while its running, only when wood is being forced onto the blade do I let it touch.

For the top wheel, I rest the front of the carbide teeth just over the front of the tyre. I know what it says about centreing the gullet, but all I've ever achieved from this is blades that snap prematurely.

I have a cheap 14 inch full boar band saw and have never managed to get it to cut in a straight line, even after watching several you tube vids on fine adjustment etc. After reading your comment I think I may have found the problem, quite possibly way over tensioned, I always struggled with the "push the side of the blade" method, I'll dial it back and see if that helps, cheers.

Originally Posted by Dengue

Moved the blade way forward to what I would normally do, based on woodPixel's comment, so that the bottom of the teeth gullet was just touching the front of the tyre of the cleaned upper wheel, and I noticed a definite improvement in the parallelism of the blade and the mitre slot, down to 1.0 degrees off line. Cut a piece of 6mm MDF with a line 25mm in from the edge, set the fence parallel to the mitre slot, made sure the guides were well away from the blade, and ran the test piece through the saw against the fence.

I also checked the tension by pushing firmly with a finger in the midpoint between the two wheels, and found it would deflect by up to 4mm. Some books say 1/4" is a good deflection. ( Just found the Laguna manual, which says to aim for 4.7 to 6.35mm defection at a point 6" below the 3 or 9 o'clock position on the upper wheel)

Outcome: The blade ran hard against the right side of the kerf, leaving quite a gap on the left side of the blade. But the blade followed the pencil line quite accurately. Same result as found previously. Which is weird, based on the attached drawing, which says if the blade twists to the right like mine is doing, the blade is too far forward

Attachment 426994

I have had the exact same problem and tried all I could think to do can you take the blade to Gregorys to try on their bandsaw
I came to the conclusion it was the RSK blade all other blades were good I had a Bi metal blade from CSK .9mm and a thin Kerf blade from Highland woodworking all good. I just put the RKS blade in the bottom draw the frustration was too much. I have seen Demos on the RSK blade and it is very impressive wish I could use it Was yours OK before it was sharpened?

Dengue, to rectify the problem I would machine the table holding bolts shank where thread does not engage to give the table some movement. It does not sound like it is out far and doing that might be sufficient to bring it close enough for the tracking to do the rest.

Sent an email to Cameron at Gregory Machinery on New Years Day explaining the problem, and followed up with a phone call 9.30 am next day. He concluded it was the table out of alignment, not the blade. Same conclusion as Chris Parks I measured the angle of the blade today to be 1.2 degrees to the mitre slot.

By 11am same day, Cameron had contacted the manufacturer in the US and received and forwarded to me a diagram and detailed instructions on how to rotate the table on the saw frame. This is truly outstanding customer service!

The fix simply involved raising the table to 45 degrees to access the 4 main holding bolts which held the trunnion assembly to the frame. Interestingly, one of these bolts was quite loose, and one was only finger tight. There are multiple bolts, assembly support bolts and adjustment screws, and a specific tightening sequence and you really had to know what you were doing. This information is not in the User Manual.

I have never lifted the table before, always using it flat and at 90 degrees to the blade, so I have never touched these bolts, never needed to. This was obviously a manufacturing fault which makes me wonder if the table was ever aligned in the first place. Suspect someone on the assembly line was interrupted or called away during the alignment process, and left the job half finished. Probably not something that would be picked up on QA with the table in position.

It only took me a couple of goes to align the blade and the mitre slot. Interestingly, if I overtightened the two bolts holding the table to the trunnion assembly, the table went slightly out of alignment to the blade again.

Have taken the new Henry Bros carbon steel blade off, and put the re- sharpened LRK blade back on, and it lined up beautifully with the mitre slot before I fitted the upper and lower guides. It is sitting in the middle of the tyre, with the sharp points in line with the leading edge of the tyre of the upper wheel.

What a beautiful sight it was to see the blade sitting right in the middle of the kerf during a test cut of 30 mm thick pine.

Many thanks to all who have contributed to this thread, and persisted with me to the end. I am leaving well enough alone for the time being, need to make sawdust. Will test Peter Young's theory later, probably when I need to change the blade

I wouldn't call a table trunnion that needs adjustment, a manufacturing fault in any way shape or form.
the fact that you have adjusted it so it is singing now, is testament to this.
I have to take my table off to move my machine out, so you get used to adjusting it.

I always prefer the idea of having the fence parallel to the mitre slot, and the table adjusted for drift. even though the bandsaw is not
the best crosscut tool, in some cases the slot maybe a reference if your fence is prone to moving

With respect to the table alignment returning to non alignment when overtightening, I had a similar problem with a tablesaw- drove me crazy to get perfect alignment stuffed up with final tightening.
The fix was to use new washers- the old ones had cupped and their set was pulling the table back into the old "comfortable"-(to the table) position. Have observed that this is common across a wide range of machines

Really glad you asked this question Dengue, It has been exactly the problem I have had for several years with my Scheppach bandsaw, and I've just put up with it after several failed attempts to rectify it, and then just simply purchased a new blade...Doh..! - It's been frustrating, But there are quite a few different posted remedies here that I have NOT tried, and I am fairly hopeful and confident I should be able to get this problem finally sorted, In advance thanks to all you contributing member posters for their helpful hints, I will let you know what the outcome is,
Thanks, Brad