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Author Topic: Servo following errors... Please, need some help.  (Read 4820 times)

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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

Offline Bloy

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Re: Servo following errors... Please, need some help.
« Reply #1 on: January 20, 2007, 11:12:06 AM »
Was the encoder card working?  did it trigger a
software "Reset" alerting that  a count discrepancy has occurred?  If so OR if not, what kind of error occured?  Was it progressive?
Did it happen all of a sudden? 
Theoretically, the card should stop the program when it senses something wrong allowing you to regroup and continue.
Re: Servo following errors... Please, need some help.
« Reply #2 on: January 20, 2007, 12:52:01 PM »
Hi

The card was working. After 2 hours it just stopped. I have no idea if the error was progressive. How
would one tell if the error was progressive. The part was a relief carving so its not possible to measure
and tell a dimensional error. To my eye the work up until the error occurred looked like it was cutting
with perfect detail.

Thanks and Regards, Barry

Offline Chip

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Re: Servo following errors... Please, need some help.
« Reply #3 on: January 20, 2007, 12:59:58 PM »
Hi, Barry

Your Gecko's are 24 to 80 volts, your servo is good to 90 volts, it should be running off your 63 volt supply.

If your second servo is lower voltage your gecko current adjust will limit the volts to it also.

For a given resistance, voltage drives the current, higher volts higher current, lower volts lower current if there is no regulator.

Adjust your gecko's current to achieve a warm to the touch servo, after power is on for awhile.

Start with low current setting, adjust it up till your servos/steppers get warm, this should put you in the ballpark on your current limit

adjustment.

Hope this Helps, Chip

Offline ger21

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Re: Servo following errors... Please, need some help.
« Reply #4 on: January 20, 2007, 01:09:31 PM »
Sounds like you should be asking Ron, if the encoder board isn't doing what it's supposed to.
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html
Re: Servo following errors... Please, need some help.
« Reply #5 on: January 21, 2007, 07:32:27 AM »
Check the settings page and see if the DRO's for the encoders change when you move the machine? Also I have mad new software that Ron will be putting out with his boards as soon as I get back and get homing working...
Fixing problems one post at a time ;)

www.newfangledsolutions.com
www.machsupport.com
Re: Servo following errors... Reply for Brian
« Reply #6 on: January 21, 2007, 08:56:47 AM »
Hi Brian
To answer your question: Yes, the DRO`s are showing movement.
Here are more details that I should have mentioned. My system has a stepper motor
on the Y axis with no encoder.
When the interface stopped the machine due to a following error.I clicked ToDro for the X and Z axis only.
I then clicked Start. The machining move was on a 45 degree cut path to the work plane.
The machine started to cut and ran in a strange direction, 90 degrees to the 45 degree cut plane...breaking my bit.
Should I have zeroed the Y axis also. I assumed that I should not, since its a stepper.
The Y axis is not linked to a encoder . Do you think this won`t work because one
of the axis is not a servo with an encoder. I have the following error for the stepper set to 100.00

Offline Chaoticone

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Re: Servo following errors... Please, need some help.
« Reply #7 on: January 21, 2007, 11:05:51 PM »
Hey Golash,
    What version of Mach are you running?


Brett
;D If you could see the things I have in my head, you would be laughing too. ;D

My guard dog is not what you need to worry about!
Re: Servo following errors... Please, need some help.
« Reply #8 on: January 22, 2007, 08:12:05 AM »
Hi
Mach3 Version 2.00
Re: Servo following errors... Please, need some help.
« Reply #9 on: January 22, 2007, 11:15:52 PM »
Well I think that we are going to have to change the code in the plugin to make it so you can turn off an axis that you don't want to have the encoders work on... Next I have to get homing working with the plugin... I don't see this taking much time so I will try to get that done as soon as I can


thanks
Brian
Fixing problems one post at a time ;)

www.newfangledsolutions.com
www.machsupport.com