Here we go again . . . MK4

[Nr1madman]

Wow!
This looks like a masterbuild!
I love it when its over complicated ;)

Fancy, funny and fantastic!

[mekanik]

Very nice,
Looking forward to seeing this finished.
Mike

[routercnc]

An update on the next bits on the list - the gantry lower bearing plates. I need to make 2 mirrored parts, here is the first one progressing -

Setting up and cutting some slots. These are to adjust one of a pair of ballnut brackets. I'm going to run 2 ballnuts pre-loaded against each other:


The other holes have been spotted (to finish on the drill press) and the profile cut out. I tried something a little different to try and get the profile size as good as possible. As this sits on the X bearings I want this to be a datum part during the build. The rough profile cut was +1.0mm, then another rough cut at 0.2mm, and finally a finish cut at 0mm. You can see the finish in the photo which is excellent. I'll check with calipers how accurate the overall size came out.


I've yet to drill out the holes on the top, and there are lots of holes required in the sides, but I thought I'd try a quick fit to make sure all was well. No bolts yet just propped together but looks good!


Here is the start of the one for the other end. I had to line this one up using a DTI and get it very accurate to avoid hitting the holes in the donor plate I'm using. I've cut the slotted holes, next up will be spotting and profile:

[routercnc]

Also, I'd made a few design changes a while back but hadn't posted them so here they are.

1. Z axis
-Twin ballscrew instead of single
-Main body machined from solid
-Upgrade from 15mm miniature rails to 20mm Hiwin





2. Y axis
-Double ballnuts, one fixed ballnut housing and one floating housing to allow pre-load to be added
-Simpler bracing pieces


3. X axis
-Double ballnuts, one fixed ballnut housing and one floating housing to allow pre-load to be added

[Davek0974]

Twin ballscrews on the Z - should be able to punch the cutter through the work with the motor turned off !

:)

[routercnc]

Cheers Dave !

It might do that yes, but it is still one stepper motor so it's not any more powerful than before. Reason for doing it is that it should help reduce vibration as both sides of the Z axis are held when machining, not just one side.

[Davek0974]

Following with interest ;)