Re: Bridgeport retrofit servo questions

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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