Re: [CAD_CAM_EDM_DRO] Re: Bridgeport! (a BIGGER brother!)

Tom,

Thanks for the comments. Would you call it a 4-phase drive, like
MaxNC? That wouldn't be hard to do. That's the way some of my early
stepper drivers were made. Used in Radiation Therapy treatment
machines. Great for parts!

The HEDS-5500 are a good find, I could use another HEDS-6100! I seem to
recall an HCTL 1000, an early quadrature decoder. Two channels per
chip? There are also the U.S. Digital decoders, about $22 ea.


Tom Eldredge wrote:

>
> Newark Electronics supplies the HEDS-5500 series encoders for about 42.00
> each. They interface perfectly with the HCTL 2020 16 bit quadrature decoder
> counter chips from the same source.
>
> <SNIP>
>
> Alan,
>
> The boss stepper drivers do not take step and direction input. They take
> phase inputs. That is why I made a little board to make these conversions.
>
> Tom Eldredge, Trustee
> ----- Original Message -----
> From: Alan Marconett KM6VV <KM6VV@...>
> To: <CAD_CAM_EDM_DRO@yahoogroups.com>
> Sent: Wednesday, February 14, 2001 5:18 PM
> Subject: [CAD_CAM_EDM_DRO] Re: Bridgeport! (a BIGGER brother!)
>
> > Joe,
> >
> > Thanks for the additional information. I'll go take another look at the
> > Bridgeports I saw (without the wife). But I think they were saying 3-4
> > grand. Not that that was a "final" price. Care to post a pix? High
> > detail, something I can print out on my laser printer and take to the
> > shop. I'm sure I saw handwheels. HUGE.
> >
> > The stepper motors would be perfect. And I have driver cards for
> > unipolar motors, as well as power supply. I even think I have room in
> > my garage, er, shop! As long as I can get riggers to move it in for me.
> >
> > Alan KM6VV
> > P.S. RANT ON! Good info!
> >
> > Joe Vicars wrote:
> > >
> > > Guys,
> > > I think you are missing what I am talking about. A Bridgeport
> Series 1 and 2 CNC were made by the thousands in the 80's. They
> > > used stepper motors, open loop, 1/2 step unipolar drive. The two
> machines are identical except for the knee and table. The series
> > > 2 weighs about 1000-1500lbs more because of a larger envelope (something
> like 15 x 30 vs, 12 x 18 for the series 1) Most had a
> > > rigid ram, but some had the regular V-ram style although these are much
> less rigid. Some have power drawbar, but most I have seen
> > > have quick change Ericson 30 taper spindle.
> > > These are not converted Bridgeports, they are dedicated CNC. No
> handwheels, ballscrews all around and 10 times better Z than
> > > you get in ANY retrofit of a standard bridgeport head.
> > > All you have to do is replace the stepper drivers with new ones, and
> put a phase converter on the spindle motor. That's it!
> > > You can do the break by hand and blow shop air into the speed control
> when you want to change speeds, or it's just as easy to hook
> > > up the air controls.
> > > As Tim pointed out, the motors won't run at their OEM performance
> level, but so what? We're talking home shop here and 30 ipm
> > > should be plenty
> > > Someone tell me where else you can get a full size 3 axis mill for
> less than 2 grand?
> > > The ONLY disadvantage is the size. Many guys may not have room.
> But I tell you I have a 10' by 20' with only a 7 foot ceiling
> > > and I would never go back to my old JET. You guys with basement shops
> would have real trouble with it.
> > > I don't care where you live, if you look around you will find one
> dead and rusting off in the corner somewhere. If you can't
> > > find one for less than 2 grand you're not looking hard enough.
> > > End of rant.