Re: [CAD_CAM_EDM_DRO] Re: Declining motor torque with lower voltage.

2500 RPM at 100 volts. I'm running them at 64 volts which is 64% of the nameplate voltage. 2500 X 64=1600 RPM. 1600RPM / 2.5:1 reduction = 640 RPM at the screw / 5 tpi =128 ipm. And due to the abundant torque of X and Y it gets all of it. I have them set at 100 ipm. Plenty fast.

Ron

cnc_4_me <cnc4me@...> wrote:


Good post Ron, could you do us 1 more favor and tell us the max rpm
your servos are rated for...

Wally



--- In CAD_CAM_EDM_DRO@yahoogroups.com, R Rogers
wrote:

> With all the discussion about servo power. Someone needs to and I

may when I get time. Do some testing and just find out how a few
different sized motors react under different circumstances. Simple
sheave mouted on shaft with a cable that lifts a weight. A variac to
vary the DC voltage. I'm guessing for X and Y on a Bridgeport that
even a nema 23 sized motor of considerable power would suffice. With
the proper ratio any servo would work. It just boils down to the
rapids that will be achieved. It just doesnt require all that much
power for X and Y. In my case, I'm using 40 lb-in motors on X and Y
with a 2.5:1 ratio and they are way overkill. I can run roughers all
day in steel and the motors never even get warm. Which shows they are
doing nothing more than basically freewheeling. Driving the knee for
Z on the other hand is a totally different situation. Drilling holes
all day, the 40 in-lb motor with 2.5:1 on the knee reduction gets
warm, not hot but very warm. So, I conclude using a

> 2.5:1 ratio driving the knee that a 40in-lb motor is a perfect

size with 60 ipm rapids without gas springs or counterweights. A
smaller servo may work for this but it will generate more heating and
may cause problems and only be suitable for short periods of service.
Unless the reduction were increased proportional to the smaller
motors size with slower rapids.

>
> Ron
>

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]