Centroid Community CNC Support Forum

This is my second Acorn project, first was a bench top Mill. The previous owner was running it with Mach3. I believe this lathe was originally a NC machine, which is what I was told by the previous owner. I'm pretty sure all the wiring and components in the cabinet on the tail stock end of the machine were used by the old NC control???

While I feel comfortable doing the next project, it's still within my capacity to do something stupid preparing the machine for the install. Primarily, I don't want to trash an existing component that would be perfectly fine to reuse, but there are a lot of things in the cabinets that aren't familiar to me.

My gut says to just remove everything electrical and build back up. Pictures below for reference.

The initial plan is as follows, I'll focus on getting motion going first, then start thinking about driving the spindle:
- Cabinet - motion - Strip all the wiring and components. I may be able to reuse the 24v power supply and some of the terminal blocks.
- Cabinet - main power - Gut the cabinet, including all the linkage and levers for spindle gear selection.
- Servos & Drives - I'd like to reuse these if possible to keep costs down. I was told the servos are from a Hardinge CNC machine and the drives are Gecko G320X. I have no clue what's up with the huge capacitors, but they are providing power to the drives. I haven't pulled everything out and checked the voltage of the power supply in the very back of the cabinet. I'm figuring if it all worked before, then I can just rewire the control side for step, direction and feedback from the encoders???
- Limit switches - I don't know anything about these components, but if they are quality items, I'd be happy to keep them in service. I used Metrol homing switches on my other build.
- Spindle control panel - This should probably be removed, I'm thinking this would be a good place to mount the monitor for CNC12.
- Pneumatic chuck panel - maybe keep this? Possibly move location? I'm sure using Acorn outputs would be straight forward, but having buttons on the machine might be nice....
- Cabinet - spindle motor and brake - I expect that all this will be removed. I have to identify a VFD and motor combo, plus drive system --> stay withe pulleys and belts? Something I can worry about later.... (Plus a spindle encoder)

Any guidance or thoughts on these items and how best to move forward would be appreciated. End of June may be a bit optimistic for making chips, but that's kind of what I'm thinking at the moment...

Thanks in advance !!

Nice machine.
First keep track of which G320 drive controls which servo motor axis. Keep them together in case they were tuned properly with each other.

Is spindle speed still controlled by a motor running the variable speed drive mechanism up and down? (Me, I would probably ditch all that mechanical stuff, get a good 3 phase inverter duty rated motor of the correct RPM and a sensorless vector drive VFD and replace it all)

Keep on the limit switches.
Please show pictures of the turret and how it is being operated. Looks like someone has modified it.

I would be apt to patching an Acorn in place of the original Breakoutboard and see if I could make it go. You will have to figure out the encoder count on the servo motor encoders. Get the make and model of the breakout board, see if you can find documentation for it. Look at the terminals and see if they indicate their purpose as to what wire goes where for the given function

Nice project. Good machine if mechanically sound and it will do what you want.

Please continue to cronicle the build.
Marty

Thanks Marty, I'm pretty excited about this machine, I've only heard good things about them...

I was was having similar thoughts about making it move... I'll examine the breakout board more closely before going too far.

Here are some pictures of the turret, let me know what you think.
Thanks
Chris

Hmm, interested to know how they make that turret rotate...pneumatic?
Also looks like they put a servo on the hand crankwheel. I'm also interested to know how much back lash there is. I assume its turning a pinion on the rack for Z?

It's been over a year ago, but I did watch the turret operate via Mach, it's pneumatic. The lock on the front side flips up and then the turret rotates... I can't quite remember if the turret lifts before rotating to each position or not.... I guess this will be a mystery solved at a later date... I'll want to get motion and spindle sorted first...

I didn't remove the servo brackets, obviously made by PO, but the underlying ball screw end mounts look to be from Hardinge, or at least purpose built to the machine. I can tell you they are not a ferrous material, non-magnetic.

There is no rack engagement on the Z, the ball screw is doing all the work. Honestly, I can't feel any backlash when turning either pulley by hand. I plan to map these screws, so we'll see what that says...