Re: Bridgeport retrofit servo questions

The X and Y are running 1:1 right now for sure. The Z I cannot tell
at the moment because the pulley is buried in the head. Most likely
it is 1:1 as well. All of the axes move with authority with the stock
steppers...this is of course after replacing a bad power transistor
to get the Y working again. Just jogging the axes around doesn't
really thrill me...I already have 2 CNCs that actually cut...I have a
bad ERS board, so remote data is not happening at the moment.

-Brady

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "cnc_4_me" <cnc4me@g...>
wrote:

>
> Brady, can you tell me what the pulley ratio's are for your x,y and
> especially Z axis is...
>
> Wally
>
>
>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, Luke1027 <luke1027@p...>
> wrote:
> > Hello Brady,
> >
> > I am in the EXACT same Boat with my Boss5.
> > I have the EXACT Same Questions.
> > I am looking for the EXACT same solution.
> > This however is not my "Bread & Butter", just trying to get it
> > working without losing steps and add much more memory for long run
> > NC CAM programs (3D-Surfaces).
> > Can I ask what motors you decided on and where you are getting

them?

> > I too am trying to do this without spending too much $$$.
> > I can tell by your questions and answers you are FAR more
> > knowledgable in doing this retrofit then I have.
> > I will be tracking this thread VERY closly ... Please share what

you

> > end up with -- Pros & Cons you may run across on the way.
> >
> > Luke
> >
> > "I have no idea how much weight I will be pushing around with the
> BP.
> > I have picked out motors that are economical, similar in power

and

> > performance of 'real' servo motors that the expensive
> upgrade 'kits'
> > use, and generally what I 'think' will get the job done. For the
> time
> > being, I am just looking for a decent combination that will get

me

> > 120 IPM rapids and excellent repeatability.
> >
> > -Brady"
> >
> >
> >
> >
> >
> >
> >
> > Luke,
> > luke1027@p...
> >
> > braidmeister wrote:
> >
> > >OK guys...I've been reading posts on here for the past few days
> > >regarding servo motors. After replacing a dead power transistor

in

> my
> > >BOSS 5 Bridgeport (just got it....Y axis DOA)...and spending way
> too
> > >much time trying to interface to what appears to be a bad ERS
> board
> > >(via serial)...I am now heading towards doing a complete

retrofit

> of
> > >the controls using Mach2.
> > >
> > >I'm on the fence about whether to retain the working steppers

and

> use
> > >Larken stepper drives ($200 ea....up to 16A/ph) plus some type

of

> > >appropriate power supply, Campbells breakout and Mach2. The down
> side
> > >of this may be that the machine doesn't move as fast as the BOSS
> > >control can move it...but this is based on feedback from several
> > >Gecko users on a BP. I am not looking to break any speed
> > >barriers...but 50 IPM rapids aren't going to cut it. I need
> something
> > >that can handle running several hours at a time. I saved for a
> while
> > >to get the BOSS...now I have to scrape some $ together to do a
> > >conversion...just so I can run the thing. I really don't want to
> do a
> > >conversion twice (always time for that, right guys??!!)
> > >
> > >The other choice that I have is to go with servos. The BP is
> > >definately well into the servo side of the servo/stepper choice
> > >threshold. Not partial to Gecko or Rutex as either will do
> (actually
> > >I am because the Geckos are cheaper). I have read that several

of

> you
> > >suggest using some of the treadmill-type motors available from
> > >surplus center. There are several DC dual shaft motors there

with

> > >pros and cons to each. I am curious as to what models would be
> best
> > >for a BOSS machine. Here are a few that were mentioned...and a

few

> > >more that I picked out: (All listed can be found on this page:
> > >http://www.surpluscenter.com/sort.asp?
> > >UID=2005012813411678&catname=electric&keyword=MBDD )
> > >
> > >1. $30. 10-1573 ~ 5100RPM rear shaft long enough for encoder off
> of
> > >10-1834. Rated at 1.5 HP & 110v. Does this have enough juice for
> the
> > >BP @ 75v? Current not advertised other than 1.4A no load.
> > >
> > >2. $22. 10-1783/10-1783-A 2.5 HP rating 6750 RPM 18.5A 130v int
> duty,
> > >95v continuous. Back shaft only .25" long. Will have to extend

to

> use
> > >any type of encoder. I am guessing that this would be a good

motor

> if
> > >run @ 75v/18.5A (within Gecko specs)...only thing I question is
> the
> > >RPM/belt reduction. What ratio do you think is best on the BP

with

> > >this motor?
> > >
> > >3. $80. 10-1906 2.0HP 130v/15A 3210RPM Continuous duty. Has good
> > >shafts for driving and encoding. Shipping wt 24#s...starting to
> get
> > >heavier. This seems like a good motor...the current rating tells
> me
> > >that it has some cookies and the RPM is half of the previous
> > >one...helping to curb insane reduction ratios.
> > >
> > >4. $90. 10-1723 1.5HP 111v/7.6A 3100RPM 2-4hr rated continuous
> duty.
> > >Looks like a good motor as well...but it is a pig. Ship wt @ 30#
> and
> > >13" long...not liking that, but rotor inertia makes up for the
> length.
> > >
> > >What do you think??? I think #3 so far might be a winner...yes

it

> is
> > >more $ than 1 & 2, but it has a beefy shaft on it, long enough

in

> the
> > >back for an encoder and the RPM isn't outlandish. I'd like 120

IPM

> > >rapids and enough torque to mill at conservative speeds.
> > >
> > >Sorry post is so long...I like to be as detailed as I can.
> > >
> > >Thanks!!!
> > >-Brady
> > >
> > >
> > >
> > >
> > >
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