Controlling three phase motors

Yes, one of these not updated homepages... Think it over 6 years now... Yes and still with my former wife... Should invest and show new stuff. But i'm so busy and lazzy.

I'm not happy with my z backlash, at least when using big cutters, but have not yet any idea how to modify to a ballnut version. And this head is heavy whent hand-cranking upwards. Problem is that the head can swing free around the round tower-zylinder.. So maybe one day i have a super idea. Until than i enjoy what i have.
And yes, the lcnc hw/sw would be easy for me. Programming in hal is quite special, but not difficult.
Mike

Hi Mike - I did have a look at modifying my machine to a ballscrew for the Z. It's not so difficult someone over on MyCNC.UK has done it very nicely on a similar machine www.mycncuk.com/threads/651-Warco-Major-CNC-build-log/page8

Going back to my first question. The very helpful people at Fehlmann have sent drawings of the later P54 machine. Apparently for the W axis it uses the same induction motor as my machine driven by an inverter with a rotary encoder mounted on the end of the rack pionion. It doesn't sound like the most accurate way of obtaining the position of the head - even with the no doubt very accurate rack and pionion set.

I'm still a little puzzled about how the induction motor can be made to position the head using the encoder and inverter set up.

Mmm... I'd like to do that too, I'll do some research. Thanks Tommy

On further thought, what about using a linear encoder? On the Picomax 54 the rotary encoder's mounted on the pinion shaft so it's not counting the motor revolutions. On the Picomax 55 is an almost identical machine, but it looks like it might use a linear encoder to feedback the W position to the CNC.

Hi David where are you located? Switzerland too, or Belgium?
I like this British idea, good idea might solve my demands , will have some sleep over such a construction. THX.

For your second vertical axis i would see it as real w axis. With joint and axis. If you go the mesa path, and in my eyes thats the only professional way (never parport for a real machine), you might find a way to mount a scale and use mesa decoder to get precicely controlled hight. This would in my eyes be a simple augmentation of a 3-axis configuration. Also your gcode generator must not know much about W.
I would use gmoccapy with tool length measurement.
Mike

Hi Mike

I'm in the UK - I've run a little business on the side for the last twenty or so years called Anglo-Swiss Tools - www.anglo-swiss-tools.co.uk. I'm more of an academic these days.

Thanks for encouraging words about the W axis. I'm definitely going to go down the Mesa route - probably the 7i76e. I'm sure I'll post again when I get round to setting it all up.

I also use the 7i76e combined with a 7i73 for my old fashoned buttons plus lcd.
Yes, not cheapo but in my eyes the mesa cards are realy on industrie level standard.

And I was just 5 minutes ago standing in front of my mill, guessing how i could implement such a Z-ballscrew... But as usual, such a project will need several months.
Have fun and stay healthy.
Mike