Re: [CAD_CAM_EDM_DRO] Z axis on the knee, how practical????

Bridgett had an air cylinder built into the knee. You adjust the pressure to
just about "float" the knee on it. This way the Z motor is only working
against the inertia of the knee and not also holding up the weight. I
normally run with the air turned off so the motor is holding the whole
weight because my cylinder had a small leak and causes the compressor to
cycle every 30 - 40 minutes. Without the assist from the air I can handle
about 150 lbs on the table before I start to get stalls when doing a rapid
that is raising the table. With the air assist on I had not problem rapiding
with 300 lbs on the table and just have not tried more weight.

How much are your servos hunting? If it is more than one encoder count than
you don't have the G340 tune correctly or you are getting interference on
the encoder line. Do you have the newer version drives with noise filtering?
If not you will want to try the Servo noise filter in the files section or
put on a differential transmitter/receiver setup on the encoder line.

Tim
[Denver CO]
Close out stepper drives, encoder, stepper motors
http://www.KTMarkting.com/CNC.html

-----Original Message-----

>Tim,
>Ok I give up. What the heck is "AIR ASSIST" on the knee?
>I'm still testing Z-AXIS on the knee on my bridgeport.
>I'm using 600 oz. in. servo & G340 drivers with Master5.
>With stepper motors on my Jet Mill/Drill, I can go to one location & go

back

>to X0.00.
>I can not get this to work with Servo motors. Also I hooked up a Shooting
>Star scale on the
>knee & (I remove the wires from the encoder on the Servo) & when it stops
>moves
>at a test setting, the Servo motors are hunting.
>Thank you,
>Al Alfano