Centroid Community CNC Support Forum

Hello All,


Just acquired an old (1997) but young (fewer than 2k hours) Hardinge Cobra 42 lathe. Quick story is - was used by a school and within the 1st year of use, axis board errors and driver parameter issues caused it to be out of commission. The school didn't have the funds to fix it so they sold it. The buyer housed it for many years without ever turning it on. We know immediately it wont operate in its current condition, so we are choosing to do another Centroid install [We have a 26" Willis lathe (Oak), Bridgeport R2E4(AiO DC), and Fryer MC-50 (I think this is Oak too?)] These were all completed by a local tech who frequents this forum - p.s. Thanks Rob.

We need to get the equipment ordered. I need assistance in choosing the correct board for the install. These are 97' Fanuc Servos (red cap) for axis traverse and tool turret position. I haven't seen the spindle motor quite yet, but I do have photos of the VFD that will be included in the attachments. I'm thinking ACORN for this one, but I am just a machinist - as much as I'd love to indulge in an install myself, I am WAY too busy at the shop to think I would ever have time to do this in a timely fashion. Can anyone confirm Acorn is the correct path here? If not, what way should we go?

Thanks,
Andy

Do you have any intention to reuse the existing axis motors?

Acorn would not be able to control them unless you can find a suitable third party AC servo drive with step and direction inputs.

Our solution for reusing existing Fanuc Alpha red cap motors is to use Oak and our AC/DC drives. I think your motors are on the smaller side and the turret motor specifically may be too small for AC/DC.

It would be more cost effective to replace the motors with new servo systems than to use Oak and AC/DC. For the axes, you'd want 130mm frame size servos with at least 6 Nm of stall torque and rotor inertia around 0.0026 kg m^2 to match the existing aC6/2000 motors.

I would look at the turret and determine how much I/O it requires before choosing the control board. It may require adding I/O expansion boards if using Acorn.

I appreciate your input on this. Sorry for the late response here. I ended up just calling Centroid and talking with sales. We ordered a hickory board and some new drives and servos. Installation is underway.

ScullMFG wrote: ↑Mon Jun 23, 2025 11:25 pm I appreciate your input on this. Sorry for the late response here. I ended up just calling Centroid and talking with sales. We ordered a hickory board and some new drives and servos. Installation is underway.

That's all good! It would be awesome if you document the build (create a build thread) here on the forums!