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

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Les Newell <lesnewell@h...>
wrote:

> Hi Michael,
>
> These servos are probably better than treadmill motors. I use

treadmill

> motors on my Boss5 retrofit. They easily give 200IPM but they need

an

> absolute minimum of 2:1, preferably 3:1 reduction. You can drill

the

> flange for the mounting holes but it is slightly small so you end

up

> with 4 cutouts rather than 4 holes. I made up special stepped

washers to

> get around that problem.
>
> Les

Hi Les, I am glad you posted this reply because I have been wondering
about your recommendation of 3 to 1 for awhile now.

Is it because you feel you need the extra torque? Or does it have
something to do with the motor rated at 6750 RPM and it just does not
run smoothly at low speeds?

Here are the specs of the treadmill motor you use #10-1783 from
surplus center.

2.5HP at 6750 RPM

Torque in oz-in = (HP / RPM) x 1 million.

(2.5HP / 6750RPM) x 1M = 370 oz-in.

370 oz-in / 16 = 23 in-lb from motor.

At 2.5 to 1 ratio = 57.5 in-lb at lead screw.

At 3 to1 ratio = 69 in-lb at lead screw.



Wally

>
> Michael Larson wrote:
>
> >Thanks to everyone for the info on these servos. The specs don't

look

> >too bad at 120 volts, which I'd be using with the pico-systems

setup. I

> >guess my real question is can I do better in the same price

range? If

> >I'm going to have to modify something to get these NEMA-34's to

work on

> >a 42 mount anyway, should I try for those 1.5 or 2.5 horsepower
> >surpluscenter treadmill motors instead? Has anybody figured out

what

> >the usable torque is on those (I would assume, for a bridgeport,
> >"enough"), and how hard is that mounting setup? Could it be as

simple

> >as drilling the flange on the output end and adapting the shafts?

I

> >know that's a lot of questions but I want to get everything right

before

> >I spend a dime retrofitting.
> >Michael
> >
> >
> >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@a..., timg@k...

> >Moderator: pentam@c... indigo_red@q... davemucha@j...

[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
> >
> >
> >
> >
> >
> >
> >
> >
> >