Bandsaw wheel alignment

[dusty]

For your sake, I did NOT want to draw THAT conclusion.

Hope it keeps on tracking!!!!!:)

JPG et al, Actually, before you draw any final conclusions from the content of this thread - you ought to pull the table off your band saw and do a thorough vision inspection of wheel and axle alignment. You might be surprised at what you learn.

[ATTACH]3688[/ATTACH]
How I located the straightedge (axle to axle)

[ATTACH]3689[/ATTACH]
Upper axle

[ATTACH]3690[/ATTACH]
Lower axle

[ATTACH]3691[/ATTACH]
3/16" gap

[ATTACH]3692[/ATTACH]
3/16" gap

The really interesting part occurs when you place a straight edge first on the upper wheel and then on the lower wheel.

Try it, I think you will be surprised. I was.

[JPG]

JPG et al, Actually, before you draw any final conclusions from the content of this thread - you ought to pull the table off your band saw and do a thorough vision inspection of wheel and axle alignment. You might be surprised at what you learn.

[ATTACH]3688[/ATTACH]
How I located the straightedge (axle to axle)

[ATTACH]3689[/ATTACH]
Upper axle

[ATTACH]3690[/ATTACH]
Lower axle

[ATTACH]3691[/ATTACH]
3/16" gap

[ATTACH]3692[/ATTACH]
3/16" gap

The really interesting part occurs when you place a straight edge first on the upper wheel and then on the lower wheel.

Try it, I think you will be surprised. I was.

I was surprised also. The upper axle extends 1/8" more proud above its rim than the lower axle.

Using Dusty's axle to axle reference(vertical straight edge), I measured the following:
Lower pulley lower rim 1/8" under straight edge.
Lower pulley upper rim 1/8" under straight edge.
Upper pulley lower rim 1/8" under straight edge.
Upper pulley upper rim 5/16" under straight edge.
This indicates that the top of the upper pulley leans AWAY from the straight edge.

Locating the straight edge against the LOWER pulley(vertically) results in measurements 1/8" less than those above.

Locating the straight edge against the upper pulley the upper rim of the lower pulley is 1/8" below the straight edge.

There is a SLIGHT play(about +/- 1/32" at rim) in the upper pulley(shaft and linkage), but this takes a set once the blade is tensioned. The measurements above were taken with tension set(to prevent the play from affecting the measurements). The 1/4" blade was riding on the back half of the tires(teeth about in the center of the tire)

I believe these measurements are consistent with my understanding of how it should be(top pulley tilted slightly out of the plane of the lower pulley causing the blade to drift slightly towards the frame so that the double bearing(guide) can control the tracking of the blade). This causes the BACK edge of ALL blades to track about 1/4" inside the center of the tire.

Corrections solicited and appreciated. TIA

[charlese]

....Charlese: If yours changes(decreases with tension) I would take a close look at the upper wheel bearing or the linkage. The tension bar exerts pressure on the arm supporting the bearing shaft, causing the bearing to try to move in a straight upward direction. If your wheel changes angle, something is moving the bearing/shaft in a direction other than vertical.

Actually, it is the Upper Wheel Arm (517640) that twists a bit when under tension. This twist is the same action that when blade comes off during use we have to twist back into position. This is now an exacting measurable operation. I believe I read 1/4" earlier, in a buried thread, and that is pretty close to what I have. Since it works, it will not be changed.

As said by one of the experts earlier, eventually this Arm (517640) will become week enough so it must be replaced. I'll try to find this instruction.

[charlese]

Here we go - a trip into the past - here are several posts that talk about adjustments of the UPPER Wheel. The first is from Nick where he says the top wheel is tilted a bit http://www.shopsmith.net/forums/showpos ... ostcount=4

The next two posts (from May of 2007) discuss the distance in front of the lower wheel a straight edge should be, when laid across the outside edges of the upper wheel. http://www.shopsmith.net/forums/showpos ... ostcount=3 http://www.shopsmith.net/forums/showpos ... ostcount=4

If you want to read the rest of this thread click here: https://forum.shopsmith.com/viewtopic.php?t=569