Re: Bridgeport retrofit servo questions 1:1 ratio

To convert lb-in to oz-in you multiply by 16...

40 lb-in is 640 oz-in

Wally



--- In CAD_CAM_EDM_DRO@yahoogroups.com, R Rogers <rogersmach@y...>
wrote:

> Good question, I've always understood them to be continual torque

ratings. If you break them down: 16 oz to the pound, a 40 lb-in motor
would be 240 oz-in continual torque. But, i'm not certain about this.
Hopefully, someone else will weigh in. I'd like to see some formulae
for calculating torque and horsepower from volts and amps of motor
ratings.

>
> Ron
>
> cnc_4_me <cnc4me@g...> wrote:
>
>
> >
> > 28 in-lb is standard, thats what I've seen most. Like proto-traks
> etc. And 40 in-lb for the knee.
>
>
> Just to make sure i understand...These are peak torque numbers,
> right...
>
>
> Wally
>
>
>
>
>
>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, R Rogers
> wrote:
> >
> >
> > cnc_4_me wrote:
> >
> >
> > --- In CAD_CAM_EDM_DRO@yahoogroups.com, R Rogers
> > wrote:
> > > The motors on my Series 1 are 40.5 in-lb and they work out to 2
> hp
> > each at 13.7 amps. They are really too big for X and Y but just
> right
> > for the knee. Usually X and Y servos are 28 in-lb. Just a rough
> idea
> > of what is normally used. Ron
> > >
> >
> >
> > I have been trying to find data on what servos bridgport used on
> > their machines...I am looking for the torque, current and pulley
> > ratios used...Can you expound on your information above and let

me

> > know if any of that is standard bridgeport or if you know the
> specs...
> >
> > 28 in-lb is standard, thats what I've seen most. Like proto-traks
> etc. And 40 in-lb for the knee. Mine is an old bandit setup
> originally and basically an after market retrofit. It used 2.5:1

with

> steppers and still does with servos on all 3 axies. I think there

was

> really no standard on ratios or motor sizing, retrofitters each had
> their own opinions on what was better. Similar to the list here.

They

> all differed slightly but did the same thing. I'm retrofitting
> another one of the Bridgeports and I just ordered the pullies. They
> are L-series 12 tooth and 30 tooth or 2.5:1 ratio.
> >
> > On a series 1 is the knee powered??
> >
> > /// Yes and no, my knee was originally powered. I don't think

many

> retrofitters used this method because especially with steppers it

was

> too problematic. I never seen the knee move on mine until I

installed

> servos (Z board fried). I wouldnt risk frying one of the good

drives

> to see if it worked. The place I bought it from was closing and

they

> had owned the mill for 20 years. The guy was 83 and had been in biz
> for 40 some years and I think he had every giblet of paper he ever
> scratched on. I litterally got a notebook full with phone numbers

of

> sources for electronics, repair people, schematics, manuals, etc.

In

> short the stepper driven knee didn't work. He said "it doesn't work
> and it isnt going to" When I got around to calling a repair person,
> as soon as he showed up, he knew the machine very well. Nice old
> German fellow but, at $80 an hour we didn't get very well

acquainted.

> He got X and Y running and I used it until I got sick of it
> (approximately 2 weeks later). I called it the
> > "skip-o-matic" I made one ill-fated attempt at retrofit with the
> original steppers and electronics alien to the group here and that
> was a disaster i.e. I could've blew on the table and stopped it.
> Anyways, I joined the group here and with their help I wound up

with

> a very nice machine. Wouldn't trade it for a brand new proto-

trak.///

> Ron
> >
> >
> > Wally
>
>
>
>
>
>
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