Stepper driven rotary table

[John Stevenson]

Bob Warfield asked to see how a stepper is fitted to a rotary table so here's a couple of pic's and a brief description as not all tables are the same but the principle is.

Here's a table with the worm removed.


The worm shaft runs thru an eccentric housing that allows you to disconnect and adjust the worm. This one is stepped at the rear and has a hardened thrust washer at the front. End float is handled by the two C nuts at the front.
All that's left is the zero ring that goes over the eccentric housing and the handwheel keyed onto the worm shaft and secured with a nyloc nut.
Many of the smaller tables are built this way, it's only when you get up in price or size that they start fitting bearings etc...

Next shot shows a completed on on top of the first table plus the modified bits to do the conversion.



First off the eccentric housing is thinned down to accept a needle thrust bearing at the rear. Another set is fitted at the front but is housed into a new one piece coupling that replaces the two C nuts and has the Oldham coupling slot machined in.
This is locked to the worm shaft by a grub screw with a copper pad under it so as not to damage the worm shaft thread.
An alloy top hatted tube is made to push fit onto the zero ring and be secured with two small grub screws.
Over this is a square laser cut plate that holds the stepper.
The top hat section is slightly longer than the recess in the square plate so it traps the motor onto the end of the tube.

Using this method it doesn't matter how it all assembles as you can square the motor up by rotating the square plate so the motor always lies square no matter what the adjustment of the eccentric is.
The stepper is shown with the other half of the Oldham coupling fitted.
he slot in the alloy tube is to allow you to get to this coupling to tighten it up in the correct place.



Shows the setup just prior to fitting the tube and motor.
Using this method the table isn't altered and can go back to a manual operation if needed.

The cable tie on the motor is only tempory whist the Araldite under the small potting box dries. This tidies up the bunch of cables sticking out of steppers.

This arrangement also applies to Vertex type tables but you need a alloy tube with a closed end so you can drill thru and install three screws to go where the division plates normally sit.

[IOWOLF]

Impressive, thanks for posting.

[BobWarfield]

Yeah, that's a great project!

Best,

BW

[jimmstruk]

YES that is great,good work. We all enjoy the pictures and ideas. Keep them coming!! Thanks JIM

[lugnut]

Sir John, Earl of Sudspumpwater, Did you give your self that name or what? That project looks great! I want a rotary table in the worst way, but other things take precedence. What are the torque requirements for that table, I'm assuming it is a 4 or 6 inch table. Keep up with the good information and posts. This forum has been lacking lately in that respect.
You’re humble servant.
Mel

[John Stevenson]

Originally Posted by BobWarfield

Yeah, that's a great project!

Best,

BW

Bob,
It's not a project it's work It's because of jobs like this I can't get onto my projects

[wbleeker]

Sir John
I saw an ad in ME for this at Arc Euro Trade is it one of your modifications?
Will

[John Stevenson]

Guilty as charged.
Ketan at Arc Euro approached me after he saw some of the various heads, tables and indexers we had converted for use with the Divisionmaster.

These tables are Chinese but are quite well made for the money.
Other people must think they are as well as we have just finished the third batch for them and this only covers the stepper / CNC version.