Questions on using a moving gantry style mini-mill...

[Boyan Silyavski]

Same thing happened here when i was testing my belt grinder, the vfd and the 3kw motor. At the end i had to open the VFD and say "bye bye" to 6 capacitors which were connected to ground. Desoldered them and now all is allright. That with the Siemens micromaster 420. Luckily the Toshiba inverter have a button to lift the capacitors from ground in urban scenario.

To check if that's the case you just check using V meter if you have leak voltage on ground pin. Carefull!

[Davek0974]

I don't think it's earth current, the breaker is not an ELCB, just a plain MCB. The whole shop is run from an ELCB and that did not blow.

I also can't risk opening it up, it's brand new and if it will not work here, it will have to go back.

[Davek0974]

All is not lost ;)

Just had a reply from the supplier - that's what i call customer service!

Hidden away under a little plastic cover is a lever - pull it and it disconnects the internal EMC filters, he thought it worth a try. Popped out to shop, pulled the thingy and plugged it in - hey presto it powered up :)

Sounds like the same setup as Boyan mentioned above.

Didn't have time to run the PC up or start the spindle but at least the breaker didn't blow. I unplugged it, waited a minute and tried again and it worked ok again.

It's a promising note to end the day on at least.

Also have the new 5mm cutters - brilliant service from CutWell Ltd. Now I just need time, it's in short supply at the moment;)

[JAZZCNC]

I had same problem with mine but unfortunatly only just seen post else could have saved you some pain. . .

[Davek0974]

Very odd, I have two other VFD's in the shop now, once upon a time I had five on various machines, none caused this issue.

Maybe the issue is worse on newer drives with tighter EMC nonsense - the others are about 5 years old.

Hopefully get cutting again Saturday, have a little test piece lined up, got to sort the z axis calibration out first.

[Davek0974]

RESULT (at last) :) Double whammy tonight :)

I had 20 minutes tonight and also had a chat with the VFD supplier this afternoon...

Double-checked my settings in the VFD and following advice from the tech guy I run an autotune sequence with everything connected up - apparently this is 100% vital with sensorless vector drives.

Huanyang vs Schneider Altivar... Like comparing apples and grapes!

The spindle sounds much smoother and quieter, draws less current too! No annoying resonance effects at certain speeds either. Success 1.

Happy with the way it was running I reached for the tacho in the hope that the speed ranges would be better, well they were, a tiny bit anyway but not enough for me!

I visited spindle pulleys again and raised the minimum speed to 6000, the result was that made my calibration worse, much worse - this gave me the light-bulb moment of realising that if lifting the minimum above zero makes the issue worse then surely taking the minimum BELOW zero would make it better - and oddly enough, it DID!

In the end I have a minimum spindle pulley of -6,500 and a maximum of +24,000 - I now have calibrated speeds from 8,000rpm to 24,000rpm to within about 200rpm of the requested speeds from Mach3 - success 2.

Next I thought i'd see if it had any power - called an S100 from mach, and gingerly tried to stall the spindle by hand - this was easy with the Huanyang drive, but I tried as much as i dare without risking injury and could not get it to stall or even change speed much! OK, so running at 100rpm is unrealistic - it uses more current, and likely won't do the spindle much good but knowing VFD's a little I know the power is usually naff at low rpm's.

So, at this stage at least I would say it's in far better shape now.

Tomorrow hopefully should be recalibrating the Z axis and starting test cuts again. I might even risk an old cutter and set the speed at the correct value, I have a feeling it will work this time and not bog down and break.

[lucan07]

Now you tell me good job I like apples just brought a 2.2kw HY VFD and spindle but at £146 delivered from UK with the eBay codes yesterday i don't think I would have got near the Scheider

[Davek0974]

£146 for spindle AND drive?? thats pretty darn cheap!

The Schneider was £148 delivered BTW

[lucan07]

Yeah saw the 20% discount for everything on eBay so had to go for it only ran from 4-10pm found a HY chinese supplier with warehouse in UK near me in Leicester so did the deal can resell on ebay for that money and still not lose so gotta be worth a shot.

[JAZZCNC]

Now you tell me good job I like apples just brought a 2.2kw HY VFD and spindle but at £146 delivered from UK with the eBay codes yesterday i don't think I would have got near the Scheider

Don't threat I fit these all the time and think Dave had VFD which wasn't setup correctly or possibly faulty. Normally they work very well above 6000rpm.

Yes the Huanyang won't match Vector drives for torque, esp at low rpm but it's more than good enough for cutting wood an aluminium between 8000-24000rpm with smaller cutters which is where you'll mostly run it.