Y-car adjustments

[dvanr]

Hi Mike

Have you kissed your x car with a block of wood and a hammer yet??
3355

The Y car was stiff in the last 10cm of travel at one end which was due to the rollers holding the car down. Removing the v rollers solves the problem.

However if you check at the ends where the rail , the strut and the flange meet you might find what I did and can fix it with a file.


3356

I'm assuming that construction is similar on the PRT and Alpha Y car at the point the arrow indicates. The end of Rail "A" sits on top of the flange "C".

On this corner I had a .5mm gap between the Rail and the Strut "B". Rather than sitting flat like it should. Filing the flange down to the top of the strut fixed it. ( You might even be able to shim up at the bottom of "B") Removing the binding associated with tight v rollers and twisted knickers


DvanR

[mikejohn]

Dick
Measured as suggested and found 1.5mm difference between the x car supports, 1.1mm difference between the v wheels.
As the distance between the wheels that needed adjusting were narrower than the 'correct' wheels, shimming would not work, unless I cahanged the thickness of the nut between the wheel and the rail.
So I gently applied the Aussie kiss, with a rubber hammer. Gently 'kissed', measured, 'kissed' measured until I had eased out the 1.1mm.
It then ran a lot better on the rails. A little adjustment on the second x-rail and it was running true and smooth.

Thanks for the solution.

.............Mike

[gerald_d]

Mike, you mentioned elsewhere that your y-car (with hold-downs) was running tight at the ends of the gantry, and that is what Dick addressed above. You seem to be talking about the gantry's fit to the x-rails, and that is quite different to what Dick is talking about.

[mikejohn]

Gerald
I was answering the first sentence.
The y problem was solved by removing the hold downs.

.............Mike

[gerald_d]

....but it is worth checking if your y-rails are fouled as Dick described above......

The Alpha rail construction struck me as much lighter/more flexible than the pre-Alpha. It looks like the Alpha is from 3/16" bent plate, while the pre-Alpha was welded 1/4" sections. I would agree with you and Dick to use a hammer to straighten problems with 3/16" plate, while I wouldn't consider it for our 1/4" welded system.

[stevem]

And if a hammer doesn't fix it.....a bigger hammer surely will.

[gerald_d]

Can you see (http://www.talkshopbot.com/forum/messages/2/4251.jpg) what happened to 2 of the surplus "hold-down" rollers? They are used at the bottom of the z-slide to assist the hardest working pair of V-rollers on the whole machine.