800w spindle - noise & controlling remotely

**HankMcSpank** · 12-10-2013

Originally Posted by Jonathan

You're correct in saying that a DC output of 230V would imply a very high current (although it's not 230V DC, 84V or even 28A), but fortunately the VFD outputs AC not DC.

I did some speed research earlier...my interpretation may be incorrect, but I thought these VFDs put out a PWM pulse stream (& relies on the inductance of the spindle coils to essentially filter the VFD output pulses & restore a sine wave from them - similar to filterless class D audio amplifiers). If that the case, then the aforementioned 230V output, will be the maximum peak to peak level of the restored sine wave)

Originally Posted by Jonathan

Have you got skype? If you're sitting there with the VFD we can probably sort this out in half an hour...

I have skype, which I seldom use & I can't immediately lay my hands on my webcam - if I find it I'll give you a shout on here :-) (but missus has furrowed brow which roughly translates into "you must not pursue this anymore this evening!")

My VFD manual is here...

http://www.mototecnica.eu/ebay/Inver...ng%20VFNC3.PDF (great for sleep inducement at this time of night!)

**Jonathan** · 12-10-2013

Originally Posted by HankMcSpank

I did some speed research earlier...my interpretation may be incorrect, but I thought these VFDs put out a PWM pulse stream (& relies on the inductance of the spindle coils to essentially filter the VFD output pulses & restore a sine wave from them - similar to filterless class D audio amplifiers). If that the case, then the aforementioned 230V output, will be the maximum peak to peak level of the restored sine wave)

Yes the VFD outputs a PWM signal which is subsequently filtered by the inductance of the spindle, but there's a bit more to it. The input to the VFD is the mains, which is simply rectified and stored in some capacitors - this is called the DC bus. The DC bus voltage is therefore around 230*1.414.. =325V DC, so the peak voltage of the PWM waveform outputted will be around 325VDC. That means the rms output voltage will be 325/1.414=230V AC. Other things do influence the DC-bus voltage and your drive can do more than use a simple PWM signal with vf control to change things, but that's not important right now...

Originally Posted by HankMcSpank

I have skype, which I seldom use & I can't immediately lay my hands on my webcam - if I find it I'll give you a shout on here :-) (but missus has furrowed brow which roughly translates into "you must not pursue this anymore this evening!")

Don't need a webcam.

**richie00boy** · 13-10-2013

Just measured my spindle and I've got 4.4 ohms between phases. When driven by AC or pulses the impedance seen is higher because of the inductance, so you can't just use simple ohms law to work out the current.

**HankMcSpank** · 13-10-2013

Originally Posted by richie00boy

Just measured my spindle and I've got 4.4 ohms between phases. When driven by AC or pulses the impedance seen is higher because of the inductance, so you can't just use simple ohms law to work out the current.

Thanks for that ...I'm measuring 3.5 ohms between all phases. (it was late & I'd been onto this all day...& with the benefit of a good nights kip, I now fully realise that my head was fogged!)

**HankMcSpank** · 13-10-2013

I guess my quickest way forward here is to buy another 800w spindle & hook that up ...if it works, then my old spindle was faulty (which I think it is), if it still trips then I can sell it on!

Some of these water cooled spindle adverts tout themselves as 'four bearing' ...do I need this if I'm only milling pcbs & acrlyic? (in other words what does four bearings bring to the party - they're about £30 more vs the cheapest 800w water cooled spindles on Ebay)

**Boyan Silyavski** · 13-10-2013

Originally Posted by HankMcSpank

I guess my quickest way forward here is to buy another 800w spindle & hook that up ...if it works, then my old spindle was faulty (which I think it is), if it still trips then I can sell it on!

Some of these water cooled spindle adverts tout themselves as 'four bearing' ...do I need this if I'm only milling pcbs & acrlyic? (in other words what does four bearings bring to the party - they're about £30 more vs the cheapest 800w water cooled spindles on Ebay)

I believe all are 4 bearing, forget the crap the sellers are telling.

I decided to read a bit again the manual, to check what the problem could be.

Lets troubleshoot a bit:

1. check if by error you programmed 230v 60HZ instead of 50HZ

2. check if you properly established accelaration and deccelaration time , i use 10 seconds

3. check 5.4 of the manual , setting your motor
AU2 should be set to 0 instead

As far as i remember, some motors had problems with the auto tuning, so don't use it anywhere for now

uL: Base frequency 1 (rated frequency) set to 400
uLu: Base frequency voltage 1 (rated voltage) set to 230
F405: Motor rated capacity set to 0.75
F415: Motor rated current set to 3.4
F417: Motor rated speed 1410 / I am lost why i set it like this/

4. 5.9
UL=400
LL=0.0

5. 5.11
Pt=0

make sure F416 is set to 60

In general avoid the stuff like boosting and so untill you make it work.

if you doubt a particular parameter just drop a line here, i will check and report

You did not mention what the trip says exactly?

**HankMcSpank** · 14-10-2013

Many thanks...I will check these parameters this evening & report back :-)

**HankMcSpank** · 15-10-2013