ELS and Solid State Controls for my PM-1340GT

[B2]

This package contains

Sounds like a conversion kit to a cnc lathe, not just to build an ELS!

 

[WobblyHand]

The second stepper for X is the giveaway. I used a 4Nm closed loop stepper for my 10x22. So I'd recommend something at that level or slightly above, maybe 6Nm. Going beyond 10Nm seems to be overkill for the application. You can always gear the motor for more torque, but it's hard (usually) to fit in an enormous motor. I actually run my motor through my QCGB, so I can step up or step down the speed. I'm set in the middle right now - just in case. My lathe was only geared and rated for 8 TPI. I've cut 4 & 5 TPI on it with my ELS. Stalled at 5 TPI when the apron chip cover ran into the head stock. In my opinion, that was a good stall. At 5 times the torque, it may have folded up the cover.

 

[rronald]

The servo I used on PM-1340GT is rated at 1.27 N-M and is NEMA 24. It's used at 6:1 reduction, so in effect has 7.62 N-M of torque in use up to 3000 RPM. It has double the torque of the one that James used. If you watch the video of Clough42 where he switches from stepper to servo, he does a graph of the torque and how a stepper runs out of torque around 1500 rpm. I've made some very heavy cuts with the 1.2 NM servo with 6:1 gearbox setting and never had problems with stalling.

That sounds like the stepperonline 400 watt integrated servo (iSV2-57TR-48V400A). I installed the 180 watt integrated servo that Clough42 used and it has stalled for me several times. However, there was always a reason for the stall (most often an operator error) that I could fix w/o too much trouble. I can easily remove 2mm in a single cut (12L14 steel) and could probably do more if I was inclined).Thus I have waffled back and forth on whether I ought to consider upgrading to the 400 watt version. It seems like the 400 watt servo is the same size as the 180.

What are the power supply specs (or power supply part number) in your setup?

 

[xr650rRider]

I used a 400W 3000RPM NEMA24 1.27NM Integrated Servo Motor 48VDC JMC iHSV60-30-40-48, the power supply I used was one that Clough42 listed in one of the early emails. It was a 48Volt and was at least 500 watt but might have been 600 or 800 watt. It was cheap and continues to work well after 3 years.

 

[rronald]

I used a 400W 3000RPM NEMA24 1.27NM Integrated Servo Motor 48VDC JMC iHSV60-30-40-48, the power supply I used was one that Clough42 listed in one of the early emails. It was a 48Volt and was at least 500 watt but might have been 600 or 800 watt. It was cheap and continues to work well after 3 years.

Thanks for the info. It's surprising that a switching power supply works well for driving the servo since the peak current is at least 20 Amps. But real life trumps spec sheets any day.