Spring washers instead of V-roller shims

[Sheldon Dingwall]

I'm having trouble with shimming the V-rollers on my gantry. I've made .010" shim washers out of brass, but they are causing the rest of the washer stack to cup. The cupped washers then rub on the bearing seal.

Is there a reason I shouldn't use steel disc springs to shim the V-rollers? It would be a lot easier to fine tune the roller position and square the gantry. The washers in my catalog provide up to 200 lbs of force each and can be stacked in parallel for more force.

http://www.spaenaur.com/pdf/sectionD/D50.pdf

[Gerald D]

Hi Sheldon

I have been away for a while, got back today . . . . .

The disc springs will be good if you have at least about 60lbs pressure on them. That is about as much as the stepper motors can handle before losing steps - the notors will give before the washers do.

Brass shims cannot carry on a small area - brass is too weak for that. Why don't you use steel shim washers? http://www.mcmaster.com/#shims-and-shim-stock/=2bumxh

[Sheldon Dingwall]

School of hard knocks lesson here. The washer springs can't hold the bolt straight. They adjust beautifully, but the idea's a bust.

What thickness of shim do you recommend? I'm thinking .005" will be a good enough resolution.

[Gerald D]

We used 0.2mm, so .005" should be okay