Thread: Makita LB1200F Bandsaw drift

Hi Asaf, another factor is table and fence alignment, it may be off axis, I recently removed my table to make lower guide adjusments and had to fiddle around a bit to get it back on course. A blunt blade may be another cause.

Lock the fence to the table, loosen the bolts holding the table to the trunnions enough that it can be moved and adjust the table and fence until the drift is eliminated. As mentioned by mark before you do all that make sure the band in new or use a known good one as it is possible for the set of the teeth to be uneven and cause the drift.

Thanks Chris and Mark - will give it another shot...
The blade btw, is not new, but seems sharp - will try a brand new one.

If you want to know where the blade is pointing in relation to the fence (& table), BEFORE you alter the table alignment

1. track the blade correctly with the guides removed or backed off (back of the gullet in the center of the tire)
2. attach a small round rare earth magnet to a 150mm steel rule
3. attach the magnet+rule to the body of the blade behind the gullets

The rule will be pointing where the blade is pointing. This will give you a good clue as to whether it is a blade set/sharpness issue or a table/fence alignment issue.

Its usually useful to try to establish what the cause of the problem is, before you attempt to fix it

That is an interesting idea. I'll have a play when it warms up a bit.

Alan...

not an original idea, just the cheap persons version of the ~$70 commercial product
https://www.youtube.com/watch?v=h49c-Ckjr9w

and https://www.youtube.com/watch?v=ZOSB2nA6sLc

Brendan

Originally Posted by T91

If you want to know where the blade is pointing in relation to the fence (& table), BEFORE you alter the table alignment

1. track the blade correctly with the guides removed or backed off (back of the gullet in the center of the tire)
2. attach a small round rare earth magnet to a 150mm steel rule
3. attach the magnet+rule to the body of the blade behind the gullets

The rule will be pointing where the blade is pointing. This will give you a good clue as to whether it is a blade set/sharpness issue or a table/fence alignment issue.

Its usually useful to try to establish what the cause of the problem is, before you attempt to fix it

Ok...interesting..
Yet, my basic question remains unanswered...
what controls the blade positioning? the upper wheel tilt? or manual placement of the blade on the tire (back of gullet)?
From what I am experiencing - manual positioning is irrelevant as soon as the wheel starts to turn - hence the tilt only matters.

If this is not the case...what am I missing?

thanks again

yes, the tracking control (via tilting the wheel) controls where the blade tracks. And yes, you will not override it by starting it in a different place, it'll always go to equilibrium point

In case you didn't know spin the wheel by hand to do the initial tracking and tensioning before powering it. If you are already doing it then......never mind.... .

Pete

I think what you are missing is that the table alignment has nothing to do with the blade. The table attaches to the table via the trunnion assembly with 4 to 6 bolts in oversized holes. If you set up a good blade to cut on the fore and aft axis of the wheels, the table can still be, or become, out of alignment with the blade, by the table moving around ( if it is used as a handle, or knocked with a decent lump of wood).

Similarly you can align the table with the cutting axis of the blade by moving it around using the play in the over sized mounting holes

The correct way to get everything aligned is to
1. put on a new blade,preferably a flex back
2. track the new blade so that the gullet runs a smidgeon (or a hair) in front of the crown on the upper wheel (using the tracking control knob [clockwise ==> moves blade to back of wheel and vice versa)
3. joint a piece of 25mm board
4. mark a line with a gauge parallel to the jointed edge
5. Cut along the line freehand, stopping at 2/3 distance
6. note the angle of the cut in relation to the miter slot (or table edge). It will show you how far out of alignment the table is from the blade.
7. move the table to minimize the angle, then repeat the test till you are happy.
8. Once you have the blade cutting in alignment with the miter slot, align the fence with the miter slot

maybe watch this video on the subject before commencing https://www.youtube.com/watch?v=vNdrkmx6ehI