Bandsaw blade drift

[Bodgers]

I don't typically have many issues with my Scheppach Basa, it normally cuts nice and true if the blade is sharp and you don't rush things.

I recently bought a thinner 6mm M42 blade from Tuffsaws thinking I'd use it for curve cutting and maybe even as a general purpose blade.

After putting it on, setting the guides and the tracking so that the teeth are on the top wheel crown I was immediately getting a sort of toe-in towards the fence where the blade wants cut towards the fence. This is so bad that the work piece will want to pull away from the fence in response.

Lots of fiddling doesn't seem to make a difference. The only slightly strange thing is that the blade teeth ride on the crown on the top wheel but on the bottom it is much further toward the front of the wheel edge.

Is this just a function of a narrow blade when making straight cuts against a fence?



Sent from my Redmi Note 5 using Tapatalk

 

[CHJ]

In my opinion you should be setting your tracking so that the blade is in line with the table mitre slot and at 90 deg. north south.

The blade location on the top wheel should be within reasonable positioning between crown (if you have crowned wheel) and the front edge (no excessive tooth overhang on the front.) Its finite location is not the prime factor in setting up. The blade relationship to your table and its mitre slot are the criteria for straight cutting.

The location on the lower wheel is immaterial as long as it has sensible location and driving well.

 

[CHJ]

Is this just a function of a narrow blade when making straight cuts against a fence?

A sharp Narrow Blade with adequate kerf clearance should be able to cut perfectly straight slices against a fence.

Done with this blade.

 

[Bodgers]

Thank you for the replies.

I found that I may have been overtightening it as well (doesn't seem to need as more force on the handle as wider blades). After releasing the tension a bit it was easier to track in the right place.

I think I do have a general problem though as the blade is sitting much further forward of the guides than previously, and the rear support guide is almost at full extension. Some more fiddling needed...

 

[Lazurus]

you will need to reset your guides on every new blade, and yes the tension is much less on narrow blades. Also I set my fence to the blade rather than try to get a blade to cut where it doesnt want to go to. Simply done and accurate results.

 

[Steve Maskery]

you will need to reset your guides on every new blade, and yes the tension is much less on narrow blades.

Yes, there is less steel to stretch, so less force required to tension it.

Also I set my fence to the blade rather than try to get a blade to cut where it doesnt want to go to. Simply done and accurate results.

Hmm. I advise against that. It's fine if you only ever want to rip, but for any kind of cross-cut or jig operation using the mitre fence, it will throw you out. Much better to set the blade true in the first place and then it will be right for both rips and x-cuts.

 

[sunnybob]

Everything as above, but if this is your first narrow blade, have you made extra certain that the teeth have not been pinched by the side guides?

A couple of seconds running the teeth through the side guides and the blade is dead.

 

[Steve Maskery]

For very narrow blades I stick a disc of thin MDF to the faces of the guide bearings and let the teeth cut their own path. Like a ZCI. I can properly support blades down to 1/16" that way. ideal for bandsawn dovetails.