Rotary Table CNC Conversion

I purchased a Vertex Rotary table (rotab/RT) a few months ago and it has seen some good use but I will hopefully use it even more for dividing in cutting my clock wheels. I have purchased the dividing set as an add-on to the rotary table which comes with three plates for easy dividing. I have studied how to use the dividing plates and after a trial with them, there is no way I can keep concentration for long enough to use them on a 60 - 120 tooth wheel! If it was 1 to 1 then maybe, but I know I`ll mess up eventually and then there are counts which can`t be done with the plates.

I know, I know .... I should be able to use them and people have used them for years and years in the past but I fancy dabbling again in CNC. When I say again, I mean after my horrific failure at converting my X3 mill to a CNC X axis! A failure maybe, but at least I know now the basics of CNC, the software and the basic setup. So here goes, this is Part 1 but I hope the complete setup to be finished within a week of this post:

This is what I am aiming for -



these are £380 for the CNC kit only (i.e not including the table), I`m hoping to build similar with some help on the electronics but more on that in the next post when it has arrived. For now, I just need to remove the handle and make a bracket to fit the motor spindle to the rotab spindle. Basically, it should look like the one above but without the electronics gizmo... for now!

Here goes:

Vertex 4" Rotab with handle removed:



I`m going to need to couple the shafts together and for that I`m buying a 12mm (shaft axis diamter of rotab) to a 1/4" (shaft dia of motor) oldham coupling. This will also compensate small amounts of miss alignment. So basically we just need to bridge the gap and make a support for the motor. I`m using a tube of ally that was in the scrap bin:


It was bored out to leave a little lip on the inside of the bottom end:


A disk was cut and bored with three holes drilled matching the rotary table threaded holes:


The disk drops down the tube and against the lip, when bolted against the rotab is locks the tube onto the table:


When mounted:


Now the motor needs to be mounted on its 4 holes in the position below but I`ll have to space it out another 25mm to fit the oldham couplings that will be inside.



So that is the idea but I need another spacer (ideally a longer tube would have done!) but I also need more width for the motor mounting points. I`m going to use this and once bored out it should work a treat!



Just need the oldham couplings to arrive and then pickup the electronics. More details next episode!

Chris