Emco PC120 Turn

[Chaz]

Yes RMS, have big manly fingers and the a and the s are quite close.

Plus, you deal with RMA stuff, so it could have been a finger memory thing. I do it often myself.

[Chaz]

Ill also check the current setting - may bump this up (if not max already) and see if its makes the response better.

[m_c]

So, since I have changed my PSU, my steppers dont seem to want to perform. It could be a cheap PSU however not sure.

If I am going to add in another PSU, should I try and increase the voltage? I cant see the exact number, I cant find these drives anywhere - but lets assume it will take 48V DC. I also need to check if the current settings are correct for the specific voltage. Currently everything runs off a 24V 10A supply.

Would it be 'good practice' to try and get the voltage as high as possible?

Have you tried running the lathe with a voltmeter (an oscilloscope would be better) on the powersupply to see how it's handling the load?

If you were getting good enough performance with 24V, I probably wouldn't be inclined to bump it up that much. I'd probably aim around 30-40V, but it would really depend on what the motors could handle. Remember higher voltage just means better performance at speed. At low speed it won't make much, if any difference.

[Chaz]

Have you tried running the lathe with a voltmeter (an oscilloscope would be better) on the powersupply to see how it's handling the load?

If you were getting good enough performance with 24V, I probably wouldn't be inclined to bump it up that much. I'd probably aim around 30-40V, but it would really depend on what the motors could handle. Remember higher voltage just means better performance at speed. At low speed it won't make much, if any difference.

Nope, but was going to do that.

The current ability of the PSU is 10A (in theory), the same as it replaces. Its Ok with slow speed, its when I try to rapid that it tends to struggle. Ill take a closer look this weekend.

[Chaz]

Interesting, no vault drop. The drives are actually 3M860.

I tried to set the current up - no change. Ive then ensure all the bits are well lubricated (the pump hasnt been run for a while), no real improvement.

Set the max speed down, seems OK at 700 although it should be able to do 2000 I think from the spec / manual.

Perhaps the lubrication is not getting to the dovetail / sliding area, difficult to get there without removing a lot of stuff. That said, it should be adjustable, will do some further research, perhaps the motors are stalling due to this.

[m_c]

I wonder if there's something else damaged. It's a bit suspicious that everything worked before on 24V, yet now it doesn't.

Without an oscilloscope, or swapping parts, it's all pretty much guesswork. The fact the relay board got damaged before, possibly suggests the BOB might also of been damaged, and is something that only shows up at higher step rates.

[Chaz]

I wonder if there's something else damaged. It's a bit suspicious that everything worked before on 24V, yet now it doesn't.

Without an oscilloscope, or swapping parts, it's all pretty much guesswork. The fact the relay board got damaged before, possibly suggests the BOB might also of been damaged, and is something that only shows up at higher step rates.

Perhaps however Ive since swapped it.

Im tempted to put in another PSU but not worth spending on. I seem recall that I was pretty much on max before. The motors look fairly old, I cant find a spec for them, perhaps something else that wasnt done correctly doing the retrofit.

[Chaz]

So, Berger Stepper motor.

4.4A, is that 50V DC?

[Chaz]

Found this - http://www.equitecnica.com.ar/files/...225212_8_9.pdf they only list 1 motor that does 4.4A, the torque matches. Max Supply Voltage is 92V according to this .... wonder if its correct. Might explain why the motor doesnt perform running 24 Volts.

[Chaz]

Noted that the drive can do a much better microstep rate. I wonder if the motor would support that and give me any better performance?