Build continues and upgrades plus review.

[Jonathan]

Build is going well and looking at adding a rotary table as a fourth axis. Anyone got experience in converting one from manual to CNC? If so what motor is most likely best to do this with. Looking at either a 4" or 6" diameter table. Any and all input would be seriously appreciated. Also looking at converting to ball-screws for all axis' as well and thinking that 12mm would do my well for that.

I just started writing a reply to this then realised that I'm a bit too late. Nevermind I'll say a little anyway...

I converted a 6" vertex rotary table to use as a 4th axis. It was easy enough to machine a bit of 3" aluminium bar to fit on where the handle/dial used to and hold the stepper. It's very sturdy, however the 90:1 ratio makes it a bit slow to turn. I think the stepper has worn the worm drive prematurely since the backlash has increased a lot from new.

A while ago I started making a faster 4th axis which I've posted about elsewhere in the forum. That's using tapered roller bearings and will be driven by a stepper via a belt, so will be faster and also strong.

[m_c]

I converted a 6" vertex rotary table to use as a 4th axis. It was easy enough to machine a bit of 3" aluminium bar to fit on where the handle/dial used to and hold the stepper. It's very sturdy, however the 90:1 ratio makes it a bit slow to turn. I think the stepper has worn the worm drive prematurely since the backlash has increased a lot from new.

In standard form, vertex rotabs have the worm/handle on an eccentric so you can engage/disenage the worm and also adjust backlash...

[Jonathan]

In standard form, vertex rotabs have the worm/handle on an eccentric so you can engage/disenage the worm and also adjust backlash...

Yes, the way I converted mine means it still does...however I've tried that and I think the worm gear might be too far gone for that to help.

[m_c]

Yes, the way I converted mine means it still does...however I've tried that and I think the worm gear might be too far gone for that to help.

Take it apart and check it. The worm wheel is just cast iron bolted onto the underside, which i discovered after removing several teeth while machining a bit 1/2" thick steel into a 12" round :-/
Someday, once I've got the mill converted, I'll get it converted into a 4th axis.