RE: [CAD_CAM_EDM_DRO] General machine discussion, was Bent Nookballscrews ?????

Hmmm. Maybe I ought to raise the price of those motors :)
Dan
Camtronics Inc

-----Original Message-----
From: Kim Lux [mailto:lux@...]
Sent: Wednesday, August 13, 2003 6:30 AM
To: CAD_CAM_EDM_DRO@yahoogroups.com
Subject: Re: [CAD_CAM_EDM_DRO] General machine discussion, was Bent
Nookballscrews ?????


Comments below.

On Wed, 2003-08-13 at 03:17, ballendo wrote:
> Kim,
>
> I'm confused... Here's what I understand so far:
>
> You have some motors which some members of the group told you were
> too small, saying you wouldn't get good performance using them...

Yes. We are using Camtronics Servos, Geckos, Nook 5 TPI ballscrews.
This setup has tons of power. We are running with 3 Amp fuses, but the
motors will take 10 Amps. 12 Amps is supposed to be the demagnetization
current limit.

Story: a bad Gcode command by our operator (not me) ran the tool into a
10 mm barstock about an inch out from the chuck and bent it about 1/8".
No lack of power here. The motors run cool all the time.

Story: We were roughing out CNC spindles yesterday with 0.020" cuts at
F16-20, depending upon how aggressive we were with the feed override.
This fully loads the spindle motor on a 13x40 lathe.

Story: we slowed down the spindle speed and were taking 0.100" cuts.
The motors are fine with that loading.

I highly recommend this setup over stepper motors. The tuning was no
problem at all.

At 900 RPM, this setup yields a G0 speed of 180 IPM, which is a bit on
the slow side. If I were building another machine, I'd aim for 300 IPM.
However the software we are using (TurboCNC) currently limits the
stepping speed to 28ish KHz, which works out to be 140 IPM anyway.

> But
> you ARE getting good performance from them, and you attribute it to
> your anti-backlash nut design, which is of a non-compliant 2 nut
> spacer type.

I just know that this setup works. The non compliant backlash setup
works very well. No problems whatsoever and everything is tight. I
*suspect* that others have motor power problems because of a number of
reasons, one which may be backlash setup.