Bandsaw wheel alignment?

[<sell1892]

Can the top wheel exhibit any free play when the saw is tuned correctly? I've got a Jet 18 inch, and the top wheel seems to be adjusted - tracking is good, with blade running right in the center of the tires - however the top wheel will wobble side to side. Up/down free play seems to be negligible; I assume due to proper setting of the tracking adjustment screw. The side to side freeplay lessens somewhat when the blade is tensioned, but will still move.

I guess I thought it should be rigid, like a properly adjusted vehicle wheel bearing. Bottom wheel is very solidly adjusted, doesn't move either way.

Anything to worry about?

Thanks, John Sellers

[Knothead]

I have that saw and there is no play in either wheel. Time to look into bearings...

Can the top wheel exhibit any free play when the saw is tuned correctly? I've got a Jet 18 inch, and the top wheel seems to be adjusted - tracking is good, with blade running right in the center of the tires - however the top wheel will wobble side to side. Up/down free play seems to be negligible; I assume due to proper setting of the tracking adjustment screw. The side to side freeplay lessens somewhat when the blade is tensioned, but will still move.

I guess I thought it should be rigid, like a properly adjusted vehicle wheel bearing. Bottom wheel is very solidly adjusted, doesn't move either way.

Anything to worry about?

Thanks, John Sellers

[George]

Nope. Tension is what controls the wobble. Just look at the tensioning system to see how low-tech it is.

[TWS]

On my 18 inch Grizzly (an old model) I found that the upper wheel mounting block fit very loosely into the tracks in the cast iron frame. Poor machining on the cast iron work. I ended up shimming both side to side and back in forth in the tracks. Now the upper wheel is very solid and adjusts smoothly. YMMV

TWS

[Andy Dingley]

What's "wobble" ? Is this a movement under force, with the tension spring pulling it back to one side ? That's normal.

Is it smaller, but not under spring tension ? That's time to look at the top bearing.

[<sell1892]

Andy, thanks for checking to see what the problem actually may be. I may not have described the "perceived problem" with enough precision.

There is not any wobble when running. As I mentioned, the blade tracks very true, right in the center of the tires. The movement I see is when I physically force the wheel side-to-side, when shutdown, as if to check for play. (That's the normal mode I'd use on a vehicle wheel - it's sort of ingrained.) The wheel moves right back when I release. I suppose this is from the blade tension? If it's not tensioned, it's much easier to move it side to side. No top-to-bottom free play movement is noticed; I think this is because the tracking adjustment screw is locked down securely?

I don't think this is a bearing problem, the saw hasn't seen that much run time. I'm just trying to ascertain if it needs any tweaking, for optimum performance.

Thanks again, John Sellers

[Andy Dingley]

I've not seen a mechanism where "the tracking adjustment screw locks down". They're usually a rather cheesy piece of garbage where the tracking adjustment acts as an end stop, and the force of the tension spring is used to hold the wheel axle against it. This works, but it will "give" in one direction if you pull (or maybe push) on it in one direction.

To check the bearings, you're usually best to grab the unbladed wheel at the _sides_ and wobble it, not the top and bottom. This may also show up sloppiness in the tracking adjustment trunnion, but that's a design problem, not wear.