JMC 220V Servos with Acorn

[RJS100]

Bench test worked great! Getting ready for actual wiring. I noticed that with my current VFD setup on the original motor, I have an additional " NoFaultOut" connected to the E-stop terminals on my VFD (DuraPulse GS21-22P0). This ensures that when I hit the E-stop, the spindle shuts down. Does it make sense to connect this in series with the servo contactor (see attached)?

Also, am I understanding if you hit the E-stop, CNC12 uses the "VFD Enable" output to stop the spindle?

One last question, is there a reason that you are using a separate 24V power supply for the solid-state relay instead of the Meanwell supply?


Thanks... Richard

[suntravel]

E-Stop cuts the power to all drives and spindle.

Meanwell only to power Acorn and NPN HomeLimit.

Uwe

[RJS100]

So you are saying that E-stop drives the analog 0-10V output "0" to stop the spindle. This would be true with the VFD as well. So what is the reason that with the VFD "NoFaultOout" is connected to the dedicated E-stop circuit of the VFD? If the AC servo does not have a dedicated E-stop circuit, wouldn't it make sense to open the servo contactor to ensure that all power to the servo is cut when E-stops is hit?

Richard

[RJS100]

Spindle Ok Question:

I finished the final wiring of the servo for spindle motor and got a spindle error on CNC12. The JMC AC servo indicates "Ready" on it's display. I have the alarm outputs (DO3+ and DO3-) connected to input 2. Hitting ALT-I shows this input is not normally closed. I then checked the continuity across DO3+ and DO3- and it is indeed open. Do these ports on the JMC servo need to be programmed as Alarm so they are normally closed and open with a spindle error?

As an additional test, I removed "Spinle Ok" from input 2 on the Wizard, the error disappeared as expected and the servo runs forward and backward! Great News!

One last question, when you run the "Load inertia ratio measurement" (AF_J-L), should this be done with the pulleys and belts connected so the servo is moving the spindle?

Thanks... Richard

[suntravel]

set P06-24 :

Set range： 0-1， factory set:1
0: When the State is valid, optocoupler cut-off
1: When the State is valid, optocoupler on

"Load inertia ratio measurement" (AF_J-L) always with all load attached

Uwe

[RJS100]

Perfect.... All working great. I am waiting for the Loctite to dry on the timing pulleys before bringing it up to speed. A bit gun shy here.

[RJS100]

Ok. With the pulley and belt connected, I ran the inertia ratio measurements (AF_J-L) and got a numerical value of 2.82. I then entered this into p01-04. I then power cycled the servo. When I ramp up the spindle speed, the servo is runs very rough, almost a jerking motion. For what it is worth, this is exactly how it ran before I loaded the inertia ratios.

Here is a quick video:

https://www.dropbox.com/scl/fi/115an0c5 ... pnhdv&dl=0

Any idea as to what is happening?

Richard

[suntravel]

It runs like this out of the box?

Should speed up smoothly.

Did you check if there is a voltage fluctuation when 0-10V is connected and servo running?

If yes you need a snubber circuit:

https://centroidcncforum.com/viewtopic. ... uit#p53742

Uwe

[RJS100]

When I bench tested it out of the box, I used a few batteries to simulate the 0-10 vdc analog input. With no load on the motor, it ran very smoothly. When I ran with Acorn, it was connected to pulleys/belts and ran roughly before and after entering the inertia information.

I did however forget to wire the snubber circuit that you had recommended. I will add the snubber circuit below and try again.

Thanks... I completely forgot this.

Richard

[RJS100]

Massive improvement here. I measured the analog out 0-10 volt signal and it was bouncing up and down a bit. Installed the snubber and huge improvement! I hear a bit of resonance at 2500 and 3500 rpms. This may be the same as the original motor, but it was so loud you would never have heard it.

I think what I am hearing could mean I need a bit more pre-load on the spindle bearings, but that is just a guess.

Thanks for all your help! So appreciated!!

New & Improved Mill:
https://www.dropbox.com/scl/fi/t9mimse1 ... mwdio&dl=0


Richard