Re: [CAD_CAM_EDM_DRO] CNC Servo motor gear ratio: overheating. EMC step rate. Table speed

On Sun, 2003-06-08 at 23:02, Jon Elson wrote:

> >
> >What is the relationship between peak torque and continuous torque on a
> >stepper motor ? I thought the torque curve was constant with RPM on a
> >stepper motor.
> >
> >

I meant to say servo here. I posted a link to several servo motor data
sheets and they can pull nearly constant torque down to 0 RPM. Only
when the speed starts increasing does the torque fall off.

> Stepper? No, the torque of a stepper motor is rated as HOLDING torque,
> and it falls off very rapidly as the motor accelerates. By 1000 RPM, most
> stepper motors have lost more than half of their holding torque.
>
> Unfortunately, there is NO fixed relationship between peak and continuous
> torque on a SERVO motor. It depends on many details of motor design,
> including wire resistance and heat conduction from the armature. The torque
> possible is constant, but the time over which you can demand this torque
> is not infinite. Above some value that takes serious effort to measure,
> the motor will eventually burn up if not given a rest.
>
> Jon
>
>
> Addresses:
> FAQ: http://www.ktmarketing.com/faq.html
> FILES: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/files/
> 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@..., timg@...
> Moderator: pentam@... indigo_red@... [Moderators]
> URL to this group: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO
>
> 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 to be 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........
> bill
> List Mom
> List Owner
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/

--
Kim Lux <lux@...>