[chbot] building CNC router - was Free stepper motors

[Richard Jones]

Following a thread on the HBRC mailing list I see there is overlap between a
CNC router project and a REPRAP for printing things in plastic. See
http://reprap.org/wiki/EMCRepRap

Richard

On Fri, Jul 1, 2011 at 4:09 PM, Mark Atherton <markaren1 at xtra.co.nz> wrote:

> Robin,
>
> Any interest in standing up and doing a 10 min talk on the subj. next
> meeting ?
>
> ..also bring along a commercial controller.
>
> Cover PC and OS requirements, interface types, software packages.
>
> What would you do differently next time ?
>
> Etc.
>
> Sounds like you could save some members a lot of hair-pulling.
>
> Regards,
>
> Mark
>
>
>
> At 02:23 p.m. 1/07/2011, you wrote:
> >Hi,
> >I've built a semi-successful CNC router/mill.
> >I haven't used it to do PBCs but have routered up to 6mm Ali
> >
> >To do PCBs the best approach seems to be using a floating engraving head.
> >This follows any contours in the board and so gives consistent cut width.
> >Otherwise it's necessary to keep the board very flat during routing.
> >
> >The biggest issue has been with using a dermal as the spindle & lack
> >of rigidity. I've made my own spindle but have blown it up twice now
> >& so it's on the "to do" shelf for a while.
> >
> >Good drive electronics are important. I started with discreet chips
> >& dropping resistors but have moved to a commercial 5 axis board
> >that uses PWM current limit & micro step. The complete board was
> >cheaper that the list price for 5 of the chips. The boards are
> >listed on trademe but I go mine direct from China for about 2/3 the
> >price all up.
> >
> >Caution some types of unipolar steppers don't like being driven as
> >bipolar & others don't like PWM current limit.
> >
> >
> >I'm happy to answer any questions & tell you what didn't work for me.
> >
> >
> >Regards,
> >Robin
> >
> >
> >
> >
> >
> >-----Original Message-----
> >From: chchrobotics-bounces at lists.linuxnut.co.nz
> >[mailto:chchrobotics-bounces at lists.linuxnut.co.nz] On Behalf Of Cass
> Jones
> >Sent: Friday, 1 July 2011 9:53 a.m.
> >To: Christchurch Robotics
> >Subject: Re: [chbot] Free stepper motors
> >
> >Thanks, having a look through now, any chance of earmarking  a set or
> >should I just get there early? has anyone here made a pcb mill or done
> >any cnc stuff before?
> >
> >On Friday, July 1, 2011, Chris Hellyar <chris at trash.co.nz> wrote:
> > > Hi,
> > >
> > > They're all 200 step nema 17's.
> > >
> > >  From memory there were no matched sets of 3, but Richard can confirm.
> > >
> > > There would be some pairs for X&Y though.
> > >
> > > If you're keen on making anything cnc-ish check out the forums on
> > > www.cnczone.com it's an awesome resource.
> > >
> > > Cheers, Me.
> > >
> > > On 30/06/11 22:23, Cass Jones wrote:
> > >> Is there a set of 3 or 3 similar 200 step motors in there by any
> > >> chance? I'm planning on making a circuit board mill as my next
> > >> project.
> > >>
> > >> On Thu, Jun 30, 2011 at 9:42 PM, Richard Jones<rjtp at ihug.co.nz>
>  wrote:
> > >>> In reply to Mark Becket I have appended photos of the stepper
> > motors to our
> > >>> last meeting pics located here:
> > >>> ChchRobotics2011June20 | 113134050398543502524
> > <
> https://picasaweb.google.com/113134050398543502524/ChchRobotics2011June20?authkey=Gv1sRgCLH0yquZjd6hVA&feat=directlink
> >
> > >>> The motors were kindly donated by Chris Hellyar when he was tidying
> up
> > >>> around last February.
> > >>> I also have a few NiMH AA cells if people want those for
> > robots. I'll bring
> > >>> these items to our next meeting on Monday 20th July 2011.
> > >>>
> > >>> Richard
> > >>>
> > >>
> >
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> >
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>
>
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