Definately a scrapyard challenge

**m.marino** · 10-02-2012

Well done Bruce.

**Jonathan** · 11-02-2012

Sorry to bring bad news, but you've put the joints on the plates the wrong way round. Normally people do it such that the top and bottom plates, to which the Y-axis bearings are mounted can move up/down a little then be bolted down to accommodate variation in the Y-axis rail spacing. You had it right in the drawing in post #87.
There shouldn't be any need to start changing things as long as the top and bottom sides of the plates are square to make the bearing plates parallel. If so then you just need to make the gantry such that there's a little bit of adjustment in at least one of the Y-axis rails. The other solution is leave the bigger plate on the Z-axis as it is and cut the smaller one to fit between and make that joint adjustable.

**JAZZCNC** · 11-02-2012

Originally Posted by Jonathan

Sorry to bring bad news

Your worse than the Grim Reaper boy. . :naughty:

Bruce he's correct but just shim if it's tight.!!

**motoxy** · 11-02-2012

I know what your saying jonathan. I made an error in the design and only realised after I had ordered the material. I have given it a lot of thought and have a system to adjust the y axis. If it becomes a problem then i will order some more material. Budgets a bit tight at the moment so I will have to see how it goes. Thanks for keeping an eye on me.

**motoxy** · 11-02-2012

Shim (spacer), a thin and often tapered or wedged piece of material

That sums up most of my metalwork

**motoxy** · 12-02-2012

Next step is the y rails. I routered out a register and then did it again. The rails edges are rounded and I did not go deep enough. Hopefully not to much wrong this time. Next will be drill and tap the rails in place.

Bruce

**JAZZCNC** · 12-02-2012

Bruce Having a register to work from is good idea BUT Becareful it can bite you with round rail.!!. . . . The base edge of round rail is often not very straight (Or Flat) so carefully check that
1: It's straight
2: The distance from rail to Edge is consistant along it's length.

If it is straight and consistant then you can work from the register when setting rails parallel if not then work direct from the round rail.

**motoxy** · 12-02-2012

Thanks for the warning. My intention is to get as much straight and parallel as possible but when setting out the various components I will use a dti on the important surfaces.

Cor if i new what i was doing i would be dangerous:naughty:

**motoxy** · 14-02-2012

quick update. Y bearings are in and the rails screwed into the box. I clamped the ends just to push it back and forth and thankfully there is no hint of binding. Mind you I am sure you will tell me what I have done wrong....

Bruce

**motoxy** · 28-02-2012

Just thought you might like to be updated. Thankfully shimming will be at a minimum as most of the crucial measurements seem to be reasonably close less than 0.1 degree.
Still got to add pads to the base of the sides and bracing on the back.

Bruce

In case your wondering I have made sliding fit pads for inside the box. These have been threaded so the tie bars although going right through will not stress the box. Once I am happy with the build these pads will be locked in place with bolts.