Parallel Distance Between Y-Rails - making a jig

[fabrica]

To get the exact parallel distances between the Y Rails correct don't you think that a Guage rod similar to what was used for the table should be used.

If so what should be the lenth of the Guage rod.

[Alan Conolly]

I get 554 from the drawings and 554.9 from the sketchup model.

424(width of carrier plate) + 2x25 (to centre of cross member tubes) + 2x46-6 (centre of fixing hole to outside edge of rail minus rail thickness) = 554.

[Gerald_D]

Havn't done a detail check yet, but 555 sounds like the right one. Alan, that 424 of the carrier plate ends in the real world as 425 between the cross-tubes.

The actual dimension is not critical because the spacers behind the v-wheels get adjusted at the end.

[Gerald_D]

Yes, 555mm is the right length for a gauge rod for the rails on the y-gantry.

[Brian_B]

Rather than use a gauge rod, I'd suggest having a gauge machined out of square steel stock (either 3/4" solid, or 1"/greater tubing with heavy walls.

Have the machine shop machine two parallel V grooves exactly 555 mm (or whatever distance) apart. These grooves should be perpendicular to the long axis of the steel.

By setting directly on top of the bearing surface for the the V rollers, this arrangement has several advantages: 1) it will index the actual bearing surfaces, and not simply the inner face of the rail's vertical portion - this is important as the unmilled surface of the angle may not be regular, and the milled V point may not be exactly centered as well; and, 2) it's a lot easier. By resting on the top of the rail, it's self supporting - a gauge rod has to be held in place somehow. The inverted V slots would be self locating and would allow the gauge and the two rails to be clamped together. I would suggest straightening and bolting one rail into position and then using the gauge to clamp/bolt the second.

If you opt to go this route, don't forget to have a second set of grooves machined for the y-rails at the same time!

Brian

[vishnu]

Hi Folks,

The distance between my X rails centre to centre is 1990 mm, my doubt is what length should be cut for the 100 x 50 mm Rect tubes for the Y axis.

Vishnu

[Gerald D]

I think 2023mm - does that look right?

[MAC2009]

On what drawing is the distance between the X&Y rails ON ?
I my be slow but i don't seem to find them?

[Gerald D]

That dimension is not on any drawing because it is not a critical dimension. If you follow the drawing instructions for drilling the rail screw holes, and then mount the rails, the dimensions will work out okay.

However, in this thread above, there are some hints.

[MAC2009]

OK it is as I have work out.

[Red_boards]

That dimension is not on any drawing because it is not a critical dimension. If you follow the drawing instructions for drilling the rail screw holes, and then mount the rails, the dimensions will work out okay.

However, in this thread above, there are some hints.

I spent a few hours on the drawings last night trying to find this detail (how far from the rail edge to drill the holes) and did not see it :confused: I looked again today and almost immediately found it on 10 20 246 :rolleyes: