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View Full Version : Vertex 8" Rotab CNC help needed



_Paul_
01-02-2013, 10:44 AM
Has anyone converted one of these to CNC/Stepper drive?

I was going to buy a set of dividing plates for it but would like some idea of the parts & cost to use a stepper/PC to drive it.

Cheers

Paul

John Stevenson
01-02-2013, 03:43 PM
Yes loads of them.
You need some rework doing on the worm, the eccentic bash wants shortening by the thickness of a thrust bearing and a new bearing fitted, they only have a thrust on one side.
Then you need a tube , stepper motor plate and stepper motor.

Add to this an Oldham coupling.

philbur
01-02-2013, 04:23 PM
If you are not intending to include it within a CNC machine/mill setup then you may need something like this:

http://divisionmaster.co.uk/divisionmaster.html

I can post some photos of the mechanical part of converting an 8" Vertex rt.

Phil:)

Jaakko Fagerlund
01-02-2013, 04:51 PM
If you are not intending to include it within a CNC machine/mill setup then you may need something like this:

http://divisionmaster.co.uk/divisionmaster.html

I can post some photos of the mechanical part of converting an 8" Vertex rt.

Phil:)
And just to add to this, the DivisionMaster can be used with CNC also, it acts as one (slave) drive.

_Paul_
01-02-2013, 06:13 PM
Gentlemen thank you very much indeed,

@Philbur yes please to the offer of photo's of the mechanical conversion that would be brilliant.

I have looked at the Divisionmaster but it looks to be a complicated build?

A little while ago Sir John did point me in the direction of the Stepperbee (http://www.pc-control.co.uk/stepperbee_info.htm) which seems very reasonably priced and moreover a sort of CNC "primer" and it requires only a PC + software and not an electronics build although I didnt realise Divisionmaster could be used as a slave.

Regards

Paul

doorknob
01-02-2013, 11:15 PM
Yes loads of them.
You need some rework doing on the worm, the eccentic bash wants shortening by the thickness of a thrust bearing and a new bearing fitted, they only have a thrust on one side.
Then you need a tube , stepper motor plate and stepper motor.

Add to this an Oldham coupling.

Could you point to documentation about the rework needed for the worm gear as well as the thrust bearing?

There was an article in Home Shop Machinist from March/April 2005, page 74 ff, that showed a conversion of a 6" Grizzly rotary table. I don't think that that particular conversion involved such changes (but I haven't read the details for some time). I have a Phase II rotab that I'd like to convert (I think that it is the 8" one) - are they all pretty similar internally?

Jaakko Fagerlund
01-02-2013, 11:42 PM
I have looked at the Divisionmaster but it looks to be a complicated build?
Nah, it is easy to put together or just order one ready made if you don't want to solder it yourself :)

gzig5
01-02-2013, 11:51 PM
I fitted a 8" Phase 2 table with a servo drive several years ago for a trade show demo to illustrate our motor line. I just removed the hand wheel assembly, fitted an aluminum adapter to mount a 10:1 Alpha gearbox driven by a 1 1/2" square Allen Bradley TL series servo motor (0.36 Nm continuous). I used a metal bellows coupling between the gearbox and drive shaft. Because the drive was in line I didn't see a need for additional bearings, but if I had used a belt drive I would have incorporated bearings for the driven pulley into the outboard end of the adapter. A 210 pound MPL-B980 (260 Nm continuous) motor that has 11"x11" face was fitted to the table top. The table would rotate the big motor back and forth and we never had a lick of trouble with the setup. Not precision positioning, but if all moves are in forward direction there would be no problem for five years of trade show duty. Back and forth might require backlash compensation depending on the worm setup in the table. It took very little torque to drive that large load and was an effective visual representation of the breadth of the motor line.