Re: [CAD_CAM_EDM_DRO] Re: Allegro 3977SED questions

Hi Ron,

You said that you added encoders. That sounds like a great idea. The
question is... where do you get the encoders themselves? I checked out your
site, and I see the boards, all the circuitry, cables, etc. But where do you
get the actual encoder units from? I assume they'd be some small units that
you can just mount on any nema23 motor shaft, right?


Michael - I found that I mostly needed the torque for rapid movements, and
for being able to reduce backlash to a minimum without stalling, not so much
because I was cutting a hard medium as opposed to foam. I also tried to see
if I could do it as cheaply as possible. Two years later, I must say that
making controllers to drive your motors (especially designing them from
scratch) is not necessarily the cheapest thing out there. But you do get to
learn a lot about PCB design and manufacturing in the process! Lots of fun
and overall enjoyable experience!

Vlad

On 12/23/05, R Rogers <rogersmach@...> wrote:
>
> The HobbyCNC (www.hobbycnc.com ) system is going to be tough to beat. I
> bought one of the 4 axis systems, had it assembled and running in a few
> hours. It's a very nice unit with resolution/microstepping as fine as 3200
> steps per motor rev. Chopper circuit. The Nema 23 motors I got with it seem
> very good quality also. Very powerful for their size. I even added encoders
> and made it a closed loop system with Mach3. No lost position.
>
> I sell the encoder board that makes this possible:
>
> www.rogersmachine.net
>
> Ron
>
> lomcevaktumble <lomcevaktumble@...> wrote:
> Vlad -
> At the moment the plans are to build a cheap-o 4 axis foam cutter.
> I'm looking at motors in the 60 - 120 oz.in. range. Fortunately not
> too power hungry! I want to do everything as inexpensively as
> possible just to see if I can do it! If everything goes well and I
> feel confident I'll probably move on to something much more
> powerful! I'm not above converting everything I own into a CNC based
> machine!!!! And a mill would be super fun! Theoretically- with
> enough CNC equipment- I'd never have to go shopping again. I'll just
> make everything in my garage!
> Your ebaying Kung-Fu skills must be much better than mine, I've
> never been able to find any steppers that I liked. They're usually
> some mixed lot of one decent one and 3 that look like something left
> over from the cuban missile crisis. I've resorted to new motor
> shopping from automation direct...the prices aren't too bad for new
> equipment.
> I do value your input...because it lets me know the limitations of
> what I'm doing. I now know that I'm not going to be doing much
> beyond foam cutting with this driver!
>
> Happy Holidays
>
> Michael
>
>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, Vlad Krupin
> wrote:
> >
> > Sorry, I must've misunderstood what you were trying to acheive. If
> you are
> > looking for something that can be put together quickly and drive a
> > 1.7-2.0Amotor at 20-30 volts, then 3977 is a great choice. Simple
> > board design, few
> > external components - it is great. I tried it, and I liked it in
> general. I
> > just had a hard time finding stepper motors that did not want 4-
> 5A... And
> > much higher voltage... Maybe my ebaying kung-fu skills are
> subpar :) So,
> > that started me down the road to designing something that could
> drive the
> > motors that I bought, and the experience was just as much fun as
> converting
> > the mill to CNC in the first place. Since I am no electronics
> expert either,
> > it did take a looong time (still learning). I thought you were
> trying to do
> > the same.
> >
> > Good luck on your project!
> >
> > Vlad
> >
> > On 12/22/05, lomcevaktumble wrote:
> > >
> > > Vlad -
> > > The 3977 seems to fit what I need it to do pretty well. The
> > > steppers I'm looking at are in the 1.7 - 2.0 Amp range. The
> machine
> > > I'll be building won't need very heavy stepper motors.
> > > I picked the 3977 because it was recommended and its seems pretty
> > > simple. I'm not an expert with electronics and I need something
> that
> > > can be slapped together by me. I also need something fairly
> quickly.
> > > Do you have any recommendations for something that might fit
> those
> > > parameters? I'm always open to looking at something else. And of
> > > course if I ever build a machine that needs more powerful motors
> > > I'll have to leave the 3977 chip for something else.
> > >
> > > Thanks for all the tips and info everybody.
> > >
> > > Michael
> > >
> >
> > --
> > Vlad's shop
> > http://www.krupin.net/serendipity/index.php?/categories/2-
> metalworking
> >
> >
> > [Non-text portions of this message have been removed]
> >
>
>
>
>
>
>
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> OFF Topic POSTS: General Machining
> If you wish to post on unlimited OT subjects goto:
> aol://5863:126/rec.crafts.metalworking or go thru Google.com to reach it
> if you have trouble.
> http://www.metalworking.com/news_servers.html
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> http://groups.yahoo.com/group/jobshophomeshop I consider this to be a
> sister site to the CCED group, as many of the same members are there, for OT
> subjects, that are not allowed on the CCED list.
>
> NOTICE: ALL POSTINGS TO THIS GROUP BECOME PUBLIC DOMAIN BY POSTING
> THEM. DON'T POST IF YOU CAN NOT ACCEPT THIS.....NO EXCEPTIONS........
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--
Vlad's shop
http://www.krupin.net/serendipity/index.php?/categories/2-metalworking


[Non-text portions of this message have been removed]