View Full Version : CNC Engraving Rotational Rotary Axis

28-07-2015, 09:56 PM
Hi folks,

I want to do some engraving on some aluminum and brass tubing. I have the Hobby Lathe and my 3 axis cnc. I thought it may be simple just to add say


http://www.mycncuk.com/attachment.php?attachmentid=15723&stc=1 (http://www.ebay.co.uk/itm/CNC-Engraving-Rotational-Rotary-Axis-50mm-chuck-3-jaw-4th-A-Axis-Tailstock-/251889999308?pt=LH_DefaultDomain_3&hash=item3aa5d05dcc)

to the bed of the cnc and it looks like it plugs into the 5th axis plug on my controller, if it doesn't have a 5 axis board I'll use a redundant axis.

Has anyone had any experience with them.. any advice ?


29-07-2015, 08:21 AM
Ive heard ones with a harmonic drive are the way to go as they have far less backlash. Im thinking about building one that can take a 125mm 4 jaw chuck that i also use on my lathe.

29-07-2015, 10:00 AM
I have one exactly like this one, but I have no idea how to do cam for it. I dont think the backlash is the biggest problem with this one, its the lack of holding power. But yeah, for sure harmonic drives are definitely a much better option.

29-07-2015, 09:17 PM
Thanks guys, or the info, I'm not doing stress cuts with the cnc its basically engraving. Harmonics look good must look further into them. Sure backlash wont be a problem though.

31-07-2015, 10:34 AM
I have a similar Chinese 4th, slightly bigger but the same principle.
Engraving will be fine, you can easily add a belt tensioner to eliminate backlash for low torque operation.
For milling operations the backplate and stepper shaft rigidity both come into play but there are cheap and smple solutions,