How important are certain tolerances?

Mostly Printed CNC - MPCNC Advice
1

Hello Everyone!

I’m into my build of the MPCNC… the US 1" SS version. Most of the parts are printed and am starting to get into some assembly.

I grabbed some 5/16" bolts and was doing some measuring.
The bearings have an ID measurement of .316" (approx.)
A standard “off the shelf” US 5/16" bolt has an OD of .306" (approx.)

The question now is, does the design have tolerances built in to account for this much play?
Should I consider other options to remove the “slop” between bolt and bearing?

Options (maybe?):

  1. Just roll with it as is?
  2. Source some metric (8mm) bolts and nuts (what does an 8mm bolt actually measure on the OD)?
  3. get some steel and mill my own parts on the lathe (YAY! more work… ugh!)?

What do guys think?
Thanks for your advice,
Trevor

2

It was designed and sold with 5/16 hardware. you should be fine.

3

Thanks for the advice Vicious… and the great build!