Re: Help with Bridgeport retrofit parts and plans

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "CalBoy101" <pt@f...> wrote:

> Hello-
>
> I'm planning to do a stepper motor CNC retrofit on a Bridgeport
> clone mill. I'm starting to figure out what I'll need, and any help
> with or comments on the following would be great. Money is tight so
> I'm trying to go with suppliers where I'll get both acceptable
> quality and good pricing.
>
> Stepper motors-
>
> From what I can tell, for a Bridgeport size mills, 1200 to 1300 oz-
> in. motors seemed to be commonly used. I'm considering the ones from
> http://www.camtronics-cnc.com/ I'm looking at their models:
>
> 1H34-113 1303 OZ IN 2.5A $195
> 1H34-114 1303 OZ IN 4.5A $195
>
> Does anybody have any comments on these motors for this application
> or a suggestion of better motors?
>

I have never seen a nema 34 stepper that could drive a Bridgeport.

> Step motor drives-
>
> The Geckodrives look pretty good to me, I guess the new revised
> version of the G210 that's coming out soon. Is that a good match

for

> the motors above?
>

If your bridgport had factory steppers then keep them. Otherwise go
servo. Low cost servo motor is treadmill motor. For encoder use
USdigital.

> Power Supply-
>
> Probably build one, but I could use some help on how many volts and
> amps I would need for the motors and drives above in a 3 axis
> system. Any comments on that?
>

1 KVA power supply around 70VDC.. May get by with .75KVA

> Ball Lead Screw conversion kits-
>
> Looking at offerings from-
>
> http://www.rockfordballscrew.com/
> http://www.hiwin.com/home3.html and
> http://www.danaherlinear.com/ballscrews.htm
>
> Anybody have comments on those guys or a different supplier I

should

> look at?
>

Rockford is the low price leader. They have complete kits for $650
or so.

> X, Y and Z motor brackets-
>
> So far I've only found these ones-
>
> http://www.elrodmachine.com/x&y.htm
>
> Real nice looking stuff, but way over budget. I guess I'll build
> them from scratch if I have to, but it seems like somebody out

there

> must be selling a lower cost bracket set that would save me some
> fabrication time, does anybody have some other suppliers I can look
> at?
>

They are definitely the high price leader. Making your own is the
way to go if you have access to another mill. There is someone on
this list that was talking about selling brackets. But hasn't
released anything yet.

> Controller Software-
>
> Will try Mach2 from http://www.artofcnc.ca/ with TurboCNC as a
> backup if Windows stability problems start driving me crazy.
>

Can't go wrong with Mack2, and do not forget sheetcam for a 2 1/2D
CAM program.

> Limit switches and "zero" switches-
>
> Any suggestions for switch types and suppliers?
>

Hard to get a deal on industrial sealed limit switches. Ebay or
http://web2.automationdirect.com/adc/Home/Home.

> Milling machine-
>
> If I can't find a used "real" Bridgeport locally in reasonable

shape

> I'm looking at the Birmingham model BPS-1649 from
> www.billstoolcrib.com . Its a step pulley model with a 3 phase

motor

> that I'll drive with a VFD, avoiding potential problems with the
> marginal mechanical vari-speed systems typically on these clone
> machines. Apparently the heads on these are made in Taiwan and not
> too bad. Any comments on this machine and its ability to accept

ball

> lead screws?
>
> Thanks for any help you can give me-
>
> Paul T.

Putting ball lead screws on a Bridgeport head is not for the faint of
heart. As a alternitve you can power the knee. Rockfordballscrew
makes a kit for this.

BTW Rockford only makes rolled screws.

Everything you want to know has been covered in detail on this list
since the beginning of the year. I would suggest reading every post
from there to current. You can't trust the title, that's why you
have to read them all. You will learn everything you need to know.

Wally