Rotary Table Project - Computer Controlled

[Vinny]

I recently decided to change my CDCO rotary table into one that's computer controlled.  I've seen a few conversions, including one on a table very similar to mine at madmodder (via homemadetools.net) but it's a smaller table and I'll be doing a different interface.

The first step was to select a piece of metal for the stepper mount.  Had a piece of aluminum 2" round and about 2.5" long.  The part of the table where the crank mounts and the backlash adjuster attaches to is 21mm.  So step 1 was to bore a hole in the 2" round to 21mm to match the backlash adjuster, then turn something to 21mm to center everything.  I didn't want to waste a piece of metal on it so I poured a piece of plastic round and turned it down to 21mm.  Plastic is much easier and quicker to machine to size and when you're done you can either toss it or put it in a box of other pieces of plastic you made for another single use.

Here is the backlash adjuster on top of the round ready to get to know a transfer punch.


The round is now punched and drilled for a clearance for an M5-0.8.


The other side is now bored to about 1.250" for clearance for the coupler between the stepper and the 12mm shaft the crank used to attach to.


I cut a piece of 0.250 aluminum plate for the stepper motor to mount to.  I used the 4 jaw chuck that came with my Logan 200 for the first time and I'm now convinced that this chuck wasn't used on this lathe.  The supplied key wasn't even close to fitting it, it doesn't screw on all the way, the jaws barely move, ...

I got the center bored for the stepper to fit into then transfer punched the stepper holes and milled it to sorta fit the stepper.  I say sorta because it's not exact, but it's close enough for this.


Here it is finished except for drilling and tapping for the stepper mount.


Or so I thought it was finished.  I also thought I was finished with that damn 4 jaw chuck.  How do I center the stepper mount and mount it to the 2" round???  

Next chapter, back to the lathe.  Hopefully the bolts ordered to mount all this stuff together are here tomorrow (they were due here today according to the USPS... HAR!).

more to come...

[Vinny]

I've been a bit lax on updating this. There was more progress so here we go...

The bolts took a few more days to get here (thanks USPS) but they finally did arrive. I got everything cleaned up, assembled and mounted on the table. The 2" round had to have the inside hole opened up just a bit in the 21mm section. It was a bit too tight for my liking so I opened it up to about 22mm.

Here it all is mounted to the table, sans stepper.



The stepper's not yet mounted 'cuze I have it on the bench to 1) change the connector and 2) because it takes up less space than the rotary table while I take care of the software/electronics part.

The software's taking the longest. I'm using a touchscreen LCD and was going to use the Arduino UNO. Two problems arose from that. 1) the library and routines for the menus alone ate up all the UNO's memory and 2) the display used all but ONE pin for I/O.

So I ordered up an Arduino Mega 2560, plugged in the display and it didn't work. So I put an LED on a couple of spare pins (the Mega has plenty) and modified the code in various places to let me know where the program was, if anywhere. Turns out, the only thing that didn't work was the display.

In their ultimate wisdom, the folks that designed the Mega changed the ports around so the pins used to send data to the display were on an empty connector. The guy that wrote the library for the display had already encountered this and there was a work around but not very well documented. Eventually I found it and you can see the result here...



The only drawback to this is the display is dog slow. I have another display coming that's made for the Mega but it's currently sitting in Customs in Chicago. So I wait....

That's it for now.

Edit: The X and Y numbers you see on the screen are just to tell me where, on the screen, it was touched. They're not part of the final work.

[TomG]

Looks like a fun project Vinny. You'll have to build a hard case for it so it'll survive in the shop.

Tom

[Vinny]

Picked up a sheet of PVC Foam that I'll be making the model for the case out of. Then a mold, then comes the plastic. I would've already made it but I wanted to wait to see what size display I ended up with.

[Highpower]

What is up with old school modeling and mold method Vinny? Where's the 3-D printer man!!!???

Just kidding. Everything you are doing is above my pay grade.

[Vinny]

The problem with the 3d printer is you have to print each one you do. With a mold you just pour resin in the mold and pull it about 15 mins later. Besides, a 3d printer is above my pay grade!!

[Vinny]

Made some more progress.  Finally got a usable display.  It's a 3.2" and is nice and fast on the Mega.  The only problem is that it required a different graphic library.  The good part, tho, is it's smaller and easier.

Next up is the stepper circuitry and the box.  I put the connector on the stepper this afternoon so that part's done.

A couple more pics...

The main screen, you've seen it before, sort of.


The keypad for entering data.  Also includes help text (that's so unlike me)!


And the Setup menu.  If Go Distance is set to anything but zero, it'll travel that distance every time GO is pressed on the main screen.  If Go Distance is zero, it'll go where the POS position is set to.  Jog Distance is how far it will travel forward or back when JOG+ or JOG- are pressed.  Set Home just sets the current position to 0.00.


That's it for now!

[Roadracer_Al]

Does it know not to jog into the work?

[Vinny]

I would hope the operator knows better than to let it.

[george356]

Are you in a position to share your code (the .ino) please, Vinny?