Re: [CAD_CAM_EDM_DRO] Heck of a time tuning servo motors.

One easy way to tell if you're underpowered is to simply push on the axis in
the direction you have it moving - then push the opposite direction. If you
can stall the motor or 'help it' then you are underpowered.

Myron Cherry

----- Original Message -----
From: "Erik Reikes" <ereikes@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Wednesday, October 09, 2002 9:37 PM
Subject: [CAD_CAM_EDM_DRO] Heck of a time tuning servo motors.


> So I've finally got my motors mounted to my machine and I'm having a
> heck of a time getting them to operate properly.
>
> The basic problem is the motors seem to stick as they slow down and
> pull huge amounts of current (greater than the 10amps I can see on my
> meter). Every so often they will stop in this state and just sit
> there pulling a ton of current. This of course eventually causes the
> fuses to blow.
>
> I'm getting the sneaking suspicion that my motors just don't have
> enough torque for this application. So they slow down to where they
> should be stopping and just stick there stalled unable to move the
> final last few clicks to get to their commanded position.
>
> Let me run down the specs of everything I've got so if there are any
> glaring errors someone can point out the component that is completely
> wrong.
>
> I'm retrofitting a shoptask 3-1 machine with regular acme lead
> screws. They are 10TPI leadscrews and I have a 2-1 belt reduction to
> the servo.
>
> I'm running G320 gecko servo drive units. These are powered by a CAM
> tronics 36V 25Amp supply.
>
> I've been using master5 to command the geckos.
>
> The servo drives I'm using are Leeson PMDC motors with 100 line
> USDigital encoders attached. I don't have a torque spec on the
> motors and can't find it anywhere on the Leeson sight, but here is
> what I do know : They are labelled 1/8HP, 24VDC, 5.7A, 3300RPM
> motors. They have 3/8" shafts and are labelled model # cm31d33nz1b
>
> I know that I am running 24VDC motors at 36VDC, but I figured for my
> likely duty cycle it would be ok. My real worry is the mystery
> torque amount of the motor. I had assumed based on the size of it
> and my gut feeling based on the available specs that I would be ok.
> Now I'm a bit worried. I will try to loosen up my gibs a bit and see
> if things improve, but this is not the ideal long term case for me.
>
> I supposed the next solution would be to figure a way to gear them
> down further . This would be quite difficult as they are allready at
> 2-1. 3-1 might just be possible with a really thin pulley wall.
>
> Any suggestions?
>
> -Erik Reikes
>
>
> Addresses:
> FAQ: http://www.ktmarketing.com/faq.html
> FILES: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/files/
>
> OFF Topic POSTS: General Machining
> If you wish to post on unlimited OT subjects goto:
aol://5863:126/rec.crafts.metalworking or go thru Google.com to reach it if
you have trouble.
> http://www.metalworking.com/news_servers.html
>
> http://groups.yahoo.com/group/jobshophomeshop I consider this as a
sister site to the CCED group, as many of the same members are there, for OT
subjects, that are not allowed on the CCED list.
>
> NOTICE: ALL POSTINGS TO THIS GROUP BECOME PUBLIC DOMAIN BY POSTING THEM.
DON'T POST IF YOU CAN NOT ACCEPT THIS.....NO EXCEPTIONS........
>
> Post messages: CAD_CAM_EDM_DRO@yahoogroups.com
> Subscribe: CAD_CAM_EDM_DRO-subscribe@yahoogroups.com
> Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@yahoogroups.com
> List owner: CAD_CAM_EDM_DRO-owner@yahoogroups.com, wanliker@...
> Moderator: jmelson@... timg@... [Moderator]
> URL to this group: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO
> bill,
> List Mom
> List Owner
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>