The Dreaded X axis stepper error using UC400ETH and UCCNC !!!

[dachopper]

Using 50 khz , .1 sec com buffer, and 300 line look ahead

[A_Camera]

Driver PSU voltage: ???
Micro stepping: ???
Stepper current: ???
Speed and acceleration: ???

The AM882 seems to be pretty complex compared with the traditional analogue drivers, are you sure it is been configured right, according to the manual?
Have you checked the signal levels at the AM882 end? How about wiring?

[A_Camera]

Using 50 khz , .1 sec com buffer, and 300 line look ahead

No benefit in using 50kHz and it is too low if you have a fast machine. Raise it to 200kHz.

[Ger21]

What's the benefit of 200Khz?
50Khz gives you a longer pulse width, which can be a benefit with some drives.

The fact that he's had this issue with both Geckos and Leadshines, means it's probably not the drives.

That would point to maybe the power supply, an issue with accel/velocity settings, or a mechanical issue.

You said the motors are very hot? What are the motor specs, and what do you have the drive current set at?

[routercnc]

You said the motors are very hot? What are the motor specs, and what do you have the drive current set at?

My thoughts exactly. I've machined lots of parts often taking an hour or more and motors are never boiling hot. Warm to the touch is the hottest they get. Try turning the current down.
My understanding is that voltage is doing the work and turning down the current will help the other parts of the chain such as drivers and psi. If they are browning out under the load that is easily on the list of lost steps suspects.

[dachopper]

Hi guys... Sooooooooo angry right now !!!!!!!!!!!!!

I just video'd the problem for the first time, it was a vertical travel move, with speed turned down to 50% of my tools recommended speed.

After 8 minutes, the tool lifted vertically while unloaded with a slow retract speed, and the Z height travel jammed for 1/2 a second just before getting to full retract height. then plunged into the part. on the next down shift. It wasn't accelerating, it was at travel speed when it jammed on nothing

The previous other error was not caused by the Z axis, as it was an X axis shift, that also must have had to jam and remain in mid air - and be unloaded for 3-4 seconds wile being sent an X command but remaining Dead still in the X axis, with the Z axis moving up making the tool cut vertically in mid air.

Current Peak is set to 3.5A with Pro tuner in the AM882

Stall detect will not function as my cut speeds are low while I try to figure out what is causing these issues

Motors are NEMA23 381oz/in 3.5A Single Shaft Stepper Motor KL23H2100-35-4A, 0.9 degree.

Power supply is PS-10N68 - 1000W 68V Power Supply running 4 of the above steppers, ( two of the motors would have been on 50% current hold ) when the other motor stalled also.

The final thing is that I tried as hard as I physically could to get the Z and X axis to jam, and i just physically cannot, even with the motors hot............ any ideas?

Remember, they both effectively jammed at travel speed, basically under no load, .... but y?

[m_c]

Is there anything still original from when the problem first appeared?

What BOB are you using?
I'm wondering if it's a faulty BOB causing issues with step/dir outputs.

[dachopper]

The only original parts are UC400ETH, UCCNC + PC software and hardware, Spindle, motors + wiring..

More clues, just had fault number 3 for today on video, I had everything running, but no drill bit in the spindle, ( All electrics on and running, spindle was turning but with no BIT. This time the X axis jammed during a left to right travel movement. just after reaching retract height, under no load. AM882 stall detect SHOULD have picked up this stall, it was at 450rpm, but it didn't........ some kind of electrical interference?

Did another RUN everything turned on again, but this time the spindle freewheeling ( inverter powered but no power to spindle ).....18 minutes later, no fault

Ok - I've now noticed that the X axis jam that happened in mid air snapped the coupling in half.

Just ordered some different spindle shielded cable - siemens proflex EMV

I do have the spindle running in the same 50mm cable carrier as the X / Y motors... would this normally be ok? I don't think I've seen a DIY machine that doesn't run this setup yet?

[dazp1976]

Motors are NEMA23 381oz/in 3.5A Single Shaft Stepper Motor KL23H2100-35-4A, 0.9 degree.

Power supply is PS-10N68 - 1000W 68V Power Supply running 4 of the above steppers, ( two of the motors would have been on 50% current hold ) when the other motor stalled also.

Nema23 running on 68V???

[Neale]

Nema23 running on 68V???

Nothing wrong with that. Most of us run NEMA23 size motors on about 68V. More volts, better performance. The motors are happy enough - mine have been running like that for about 7 years now. As long as your driver can take it (and again, that's why a lot of us use 80V drivers) there's no problem. Just tweak the max current settings on the drivers so that the motors don't overheat.

Somewhere there is a guideline formula (originally from the Gecko people, I believe) that suggests that around 50V is the optimum. Firstly, this is a guideline and not a hard-and-fast rule, and secondly, it's wrong anyway. Go by other people's experience!