Topics

31

General Mach Discussion / Servo faults are showing up again

« on: April 20, 2007, 07:25:45 PM »

Hi
 
I thought I had my problems with servo faults solved. Art had mentioned to set Mach3 to sherline mode. That seemed to end the errors on the X axis servo. Just to play it safe I ordered shielded and twisted paired cables and line drivers from US Digital. Now that I have the cables and driver installed for the x and z axis the x is faulting again. It always seems to be the direct drive servo on the x and never the z. I have the Rogers machine encoder interface card so it will stop the machine if the following error gets too large. A few weeks ago I was cutting a 3D part at 100 ipm with a following error set to .005. I didn`t have any problems with faults. Now I have the following error set to 1 inch and the axis faults after it moved .5
I`m lost.
 

Barry

32

General Mach Discussion / servo following error problems

« on: March 25, 2007, 11:45:27 AM »

Hi

My main problem is trying to get a close following error to
maintain accurate part machining. The Rogers Interface card has
software settings that allows a maxium following error before the
system is hauled.
Just today I had some strange results. The first time I started the
machine the following error DRO for the X axis was paging
between .005 and .00055. Twenty minutes latter the axis was
reading .0153 to .0253. It seemed even when the machine was not
cutting a part its following error was increasing. For awhile now I
had the following error set to .020 just to get a few jobs done. Any
following error less then .020 would cause the interface card to
stop the machine.
Latter in the day I shut down the machine and Mach3. I changed the
following error to .003. I decided to run some code at 100 ipm and
on a 45 degree cut plane.
To my surprise the machine cut the part without a fault. Normally in
the past with a .003 following error set, the machine would fault
and stop just as soon as I pressed the RUN button. I`m starting to
think its a grounding issue. I purchased a pre- made encoder cable
from US Digital. I just looked at it and it seems its unshielded.
I`m not certain whats going on with my system but its very
frustrating.

Regards barry
http://www.rogersmachine.net/encoderinterface.html

33

General Mach Discussion / Servo following errors... Please, need some help.

« on: January 20, 2007, 09:48:53 AM »

Hi
I finally finished installing Roger`s Machine interface card to
monitor following errors.
http://www.rogersmachine.net/encoderinfo.html
I was running a relief caving and thought I was doing fine. Two
hours of machining with no following errors. To my surprise the part
had a error and I was unable to save the part. The cut rate was 55
ipm. I was using a following error of .025.
I`m not certain how to solve this problem ...I`d appreciate some
help.

Mach3 Motor tuning
X Servo 1110 oz*in Vel = 163.8 No gear reduction, linked to a 5 tpi
ballscrew
X Accel = 7.65
=========================
Y 1200 oz*in Stepper Vel= 117
Accel= 17
=========================
Z Servo 360 oz*in Vel 82.8
Accel = 3.15 3 to 1 gear reduction
==========================
The X and Z Servos share a 24 volt power supply. This PS has a
maximum amperage rating of 10 amps. I`m wondering if the motors
can`t draw enough amperage. The current pot on the Geckos is set to
about 75 % of its maximum. I have two power supplies in the control
box
One is 62 volts that run my Y axis stepper. I`m wondering if could
take my 1100 servo motor and run it off of my 62 volt 15 amp power
supply. This might allow all the motors to see more amperage if
that`s the problem. The servo has a max voltage 90 volts. I`m
thinking I could safely run the 1100 Servo on the 62 power supply.

Barry

34

General Mach Discussion / Sound Logic Encoder Interface Problems

« on: October 22, 2006, 10:28:48 AM »

Hi All

I`m wondering if anyone can help me get my interface card working. I had a hell of a time
getting the second parallel port card to work but now it is. I have my X axis servo wired into
the new interface board but for some reason I`m not getting any movement. I did notice that
the Gecko fault light is always on so maybe thats somehow the problem.

Barry
http://www.rogersmachine.net/encoderinterface.html

35

Show"N"Tell ( Your Machines) / Mill | Router

« on: July 30, 2006, 03:57:49 PM »

Hi
The machine is getting close to completion. I upgraded the spindle to a R8 spindle from the LittleMachineShop. I have converted my Z axis to a servo and may change to servos on the other axes.  I have tried aluminium, brass, wood and cast iron with great results.  It seems like the project will never come to and end. I almost hope it doesn`t... its been too much fun.
Regards Barry