Tool changer Macro for Ratchet Style ATC Lathe Turret?

[MatterHKR42]

Hello all,

I originally posted this question to the Facebook group but wanted to add it here as well in case anyone else runs into the challenge.

Ive been working on recontrolling an old light machines / Intelitek Prolight 3000 lathe. So far the Clearpath servos on Z and X are tuned and doing their job well. The spindle needed a different encoder than what the lathe had OE, but that's been sorted with a differential quadrature encoder. It cuts hardened 4140 like a champ.. cuts good threads.. currently loving the utility of the simple operation tools. its shaping up to be an excellent addition to my shop and the capability it brings is much needed.

Last on the list is figuring out the ATC turret. its a ratchet and pawl style with 8 positions. I currently have it set up on a cheap stepper motor and G250x stepper drive with the current set resistor cutting the torque of the stepper by 70%. its set up in CNC12 as axis C as a rotary axis which is letting me index tools by rotating the C axis in the VCP, but i have to touch off each tool, each time. The issue is the system locks by reversing the turret so the pawl jams into the ratchet for each position. during this, the motor stalls (by design) and loses position. Reading other posts about lathe turrets, it sounds like this is something that CNC12 doesn't have a built-in macro for.

Has anyone created a macro for these style turrets? or know of a way to use the built in functions for CNC12 to make this work?

Thanks in advance!

[PhilipTrueman]

Does your turret have a proximity sensor behind the ratchet mechanism? I have a turret like yours but my turret has a proximity sensor that senses when each lobe has passed the sensor. See Photo.

I will post the homing macro and the turret macro next week when i go to my workshop. If you reduce the power to your motor too much it will stall the motor when it goes forward IF the feedrate is set too high. I have an encoder on my turret motor. As you can see the turret also has 2 dowel pins to make the turret more rigid rather than relying on the 4 turret bolts. Also the turret is AXIS number 4 and is the A axis and not the C axis as you refered to. The C axis is the lathe spindle.
Which country are you in?

[PhilipTrueman]

These are my settings for the stepper motor on the turret.
Have you set the turret in the wizard as an axis driven turret, and told centroid that it has 8 tools?

[Chaz]

I'm also trying to get a similar ATC working. On the current Wizard there is a 'move forward' and 'rotate back' numbers however I cant make sense of how the 'rotate back' works. I've tried different values and I thought I understood what it was doing but its not consistent between tool changes.

Does anyone know if the A Axis needs to be set for a 1:1 turn ratio like in the 'old days'?

[Chaz]

OK, got mine to work. Finding the exact turns for 1:1 took a while, then some fine tuning ...