Re: Bridgeport retrofit servo questions 1:1 ratio

>
> 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 <rogersmach@y...>
wrote:

>
>
> cnc_4_me <cnc4me@g...> 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