No, 2500 Oz-In would break things. Usually, because steppers lose
so
much of
their (holding) torque when moving, a servo with a much lower
rating can be
used. I'm using a motor with about 150 Oz-In torque on my
Bridgeport quill.
This isn't a BOSS quill, but a manual head with an external
ballscrew
added to
the front. The Bridgeport power feed has an overload clutch that
is to
be set
at 200 Lbs. linear force, so you don't want more than that, anyway.
So, I'm suspecting there is some other problem that is causing
lost steps.
Could a pulley be loose and slipping? I've sure seen this before.
Make sure the lube system is getting to the quill ballscrew, the
lines
or metering
orifices can clog up.
Jon
I reread the advert at homeshopcnc.com. Its 850 oz-in PEAK. 170
constant. Its definitly not a pulley slipping, I can watch the end
of the motor shaft. I wrote a short program to just move the quill
up and down, and watched it. It can go up and down a hundred times
and then it just kinda stalls on one move and makes a nasty grinding
noise but just creeps a little. When the controller sends it the
other way, it takes off and goes fine again for a while. If it was
something that happened everytime i did something in particular it
would be easy to diagnose. I don't know if it helps, but everytime
I run a program and it does this, it seems to lose steps in the same
direction everytime it does it. Like in this program everytime it
loses some it will be higher, or the next time I run it they will
always be lower. Or say I'm running a 3d part where the x moves
back and forth stepping .005 in the y every pass, (z axis making the
profile) the whole part will be tapered from the lower to higher y
values at a fairly consistent taper. Sometimes it tapers up,
sometimes down, and ocasionally it works fine. If instead it lost
steps both directions, it would be rough and jagged, but not
consistently tapered.
Thanks
Nathan
