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 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....
I`m aiming for something with functions like the divisionmaster-http://www.jeffree.co.uk/divisionmaster/divisionmaster.jpg
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 later. For now, I just need to remove the handle and make a bracket to fit the motor spindle to the rotab spindle.
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:
<img style="WIDTH: 400px; HEIGHT: 300px" src="http://www.raynerd.co.uk/images/rotarycnc1a.JPG
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:
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!
I drilled and tapped the larger circular motor bracket disk to accept the M5 bolts that would ultimately hold on the motor. I then bored a hole in the centre:
The Oldham couplings are 12mm one side to lock onto the Rotab shaft and 1/4" on the other side for the motor shaft. Then the spacer/link in the centre.
All the parts ready to fit together:
And then the motor mount complete:
I have hooked it up to Mach3 after I had done this and and it is working.
I finally picked up the electronics tonight and will post more details about the source shortly. The electronics to make the indexing divice came to short of £30. I already had a Nema23 stepper motor and Routout Driver 2.5A which were also used. The Driver is shown below:
This is the indexer:
Apparently the electronics is quite straight forward since the "brains" in programmed in the chip. If I`m being honest, it means nothing to me and looks hugely complicated...
However, its functionallity does mean a lot to me and it is TRUELY EXCELLENT!!
These are the functions:
I will discuss the rest in time as and when I have played with it more and taken pictures but basically you can step by 0.01 of a degree, 0.1, 1.0 and 10 deg with quick single button steps. You can jog in any steps. You can divide 360 in to 0-999 divisions. Continually rotate the table in either direction and even programme in command steps! It is brilliant! Backlash compensation is also included!
To divide which I need for my clock building, you select it from the start menu and enter the number of divisions:
You then press the direction button to move directly to the next division!! No fuss, just a button!!
I just need to encase the hole lot and make some labels for the buttons (which I now know off by heart after using it for the past couple of hours without any markings)!
Hope you enjoyed. I`m going to post a picture of this when I get the housing but it could be a couple of days before it arrives. I was going to make my own housing but for the sake of £8 it is worth buying a premade one that fits the display and keypad nicely.