2024-03-08

Last modified: 2024-03-09 21:37:35

Machine design

Now with mounting holes in the ballnut holders & BK12 bearing holders:

Also I've shifted the ballscrews so that they're centred in the space between the adjacent planes.

Actually, perhaps I should shift it so it is closer to the "moving" surface, and that way I won't need to gouge out such a big channel in the "stationary" surface? Especially if I cut the top off the ballnut holder. I'll have to cut a bigger pocket for the ballnut holder, but that is a lot less work than cutting a big pocket for the entire length of the screw.

I've started on hollowing out the ballnut holder attachment points:

The cut-out is 11mm deep, will obviously have rounded corners in practice but I've left room for that.

Suggested order of operations for construction:

1. remove ballnuts from ballscrews, by winding them on to a (3d-printed?) holder that will stop the balls falling out
2. cut 2mm or so off the top of the ballnut holders, resulting height needs to be less than 39mm
3. see if the ballnuts will fit in the holders without protruding, if not trim the ballnuts as well
4. cut ballscrews to length with angle grinder
5. make a "spider" for the lathe to stop the ballscrews whipping
6. make new ends for the ballscrews on the lathe (with 16mm collet?)
7. put ballnuts back on ballscrews
8. go back to CAD and work out order of operations for making the frame parts

I might leave the "loose" end of the ballscrews unsupported, in which case it doesn't really matter if I can't turn them on the lathe because they don't do anything anyway, just need to be a clean enough cut to get the ballnuts back on, which can probably be done adequately with the grinder.

Instead of winding the ballnuts on to a dedicated holder, perhaps I could use the ballscrew offcuts as holders? Just need to cut the ballscrews down before I remove the ballnuts.

The things that need doing are:

• ballscrews cutting to length, and preferably a new end made on the lathe
• 2mm or so cut off ballnut holder height
• possibly ballnuts trimmed (just with grinder) so they don't protrude above reduced ballnut holders
• put ballnuts back on, all facing the correct direction

What are these sorts of spacers/washers called?

ChatGPT can't tell me.

Still needed in CAD is:

• hole locations on Y rails (need Y rails to arrive first)
• hole locations for BK12s
• hole locations for ballnut holders
• hole locations for bolting to carriages
• hole locations for spindle clamp
• hole locations for bolting frame pieces together (need to decide on sizes etc.)
• motor mounts