Re: [CAD_CAM_EDM_DRO] Opinions on these Reliance 0690 servo motors for BP conversion

Cal,

The continuous rating is 4 amps and should not be exceeded. The seller claims they are 5.5 lb-in per amp which makes them 22 lb-in motors. Which is hard to believe from a Nema 34 servo with a 3/8 shaft. The ad also goes on to mention that little or no reduction is required. That might be ok for a small mill but definitely not a full sized Bridgeport or clone. If you wound up needing a 4:1 reduction to have enough available torque to the screw, at 1200 rpm on a Gecko. Divide that by 4 and then by 5 tpi, you'd get rapids of like 60 ipm, optimum. I'd be careful buying these to use on a Bridgeport. Powering the knee would be out of the question and powering the spindle traverse for Z would require alot of reduction for torque to drill holes. One thing to keep in mind when looking for B'port servos is that no retrofitters that I know of use anything less than Nema 42 motors. If it were possible to use Nema32's at least a few would be using them because that is the most expensive part of
the package.

Ron






CalBoy101 <pt@...> wrote:
As is a poster a few posts below, I'm looking seriously at these
Reliance servo motors for use in a Bridgeport clone conversion.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7511611969

They have the following integral encoder:

Integral Encoder: Agilent P/N HEDS 5605#A06

500 Line yielding 2000 Counts/Rev.

The motors have a nominal voltage rating of 120 volts at 4 amps
continuous. The seller claims they will work fine with a Gecko drive
at 80 volts. The coders are 500 lines, yielding 2000 counts per
revolution.

The seller also claims these are big enough for a BP conversion.

Will these motors have enough power for a Bridgeport conversion, and
is the encoder count correct for this? The fact that the are Nema 34
size instead of the Nema 41 size more commonly used on BP's is
making me nervous.

I originally was planning to use stepper motors as I thought servos
would be too expensive, but if these will work I'll go servo.

Thanks,

Paul T.




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@... davemucha@... [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


Yahoo! Groups Links









[Non-text portions of this message have been removed]