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 <a href="http://reprap.org/wiki/EMCRepRap">http://reprap.org/wiki/EMCRepRap</a><br>
<br>Richard<br><br><div class="gmail_quote">On Fri, Jul 1, 2011 at 4:09 PM, Mark Atherton <span dir="ltr"><<a href="mailto:markaren1@xtra.co.nz">markaren1@xtra.co.nz</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
Robin,<br>
<br>
Any interest in standing up and doing a 10 min talk on the subj. next meeting ?<br>
<br>
..also bring along a commercial controller.<br>
<br>
Cover PC and OS requirements, interface types, software packages.<br>
<br>
What would you do differently next time ?<br>
<br>
Etc.<br>
<br>
Sounds like you could save some members a lot of hair-pulling.<br>
<br>
Regards,<br>
<font color="#888888"><br>
Mark<br>
</font><div><div></div><div class="h5"><br>
<br>
<br>
At 02:23 p.m. 1/07/2011, you wrote:<br>
>Hi,<br>
>I've built a semi-successful CNC router/mill.<br>
>I haven't used it to do PBCs but have routered up to 6mm Ali<br>
><br>
>To do PCBs the best approach seems to be using a floating engraving head.<br>
>This follows any contours in the board and so gives consistent cut width.<br>
>Otherwise it's necessary to keep the board very flat during routing.<br>
><br>
>The biggest issue has been with using a dermal as the spindle & lack<br>
>of rigidity. I've made my own spindle but have blown it up twice now<br>
>& so it's on the "to do" shelf for a while.<br>
><br>
>Good drive electronics are important. I started with discreet chips<br>
>& dropping resistors but have moved to a commercial 5 axis board<br>
>that uses PWM current limit & micro step. The complete board was<br>
>cheaper that the list price for 5 of the chips. The boards are<br>
>listed on trademe but I go mine direct from China for about 2/3 the<br>
>price all up.<br>
><br>
>Caution some types of unipolar steppers don't like being driven as<br>
>bipolar & others don't like PWM current limit.<br>
><br>
><br>
>I'm happy to answer any questions & tell you what didn't work for me.<br>
><br>
><br>
>Regards,<br>
>Robin<br>
><br>
><br>
><br>
><br>
><br>
>-----Original Message-----<br>
>From: <a href="mailto:chchrobotics-bounces@lists.linuxnut.co.nz">chchrobotics-bounces@lists.linuxnut.co.nz</a><br>
>[mailto:<a href="mailto:chchrobotics-bounces@lists.linuxnut.co.nz">chchrobotics-bounces@lists.linuxnut.co.nz</a>] On Behalf Of Cass Jones<br>
>Sent: Friday, 1 July 2011 9:53 a.m.<br>
>To: Christchurch Robotics<br>
>Subject: Re: [chbot] Free stepper motors<br>
><br>
>Thanks, having a look through now, any chance of earmarking a set or<br>
>should I just get there early? has anyone here made a pcb mill or done<br>
>any cnc stuff before?<br>
><br>
>On Friday, July 1, 2011, Chris Hellyar <<a href="mailto:chris@trash.co.nz">chris@trash.co.nz</a>> wrote:<br>
> > Hi,<br>
> ><br>
> > They're all 200 step nema 17's.<br>
> ><br>
> > From memory there were no matched sets of 3, but Richard can confirm.<br>
> ><br>
> > There would be some pairs for X&Y though.<br>
> ><br>
> > If you're keen on making anything cnc-ish check out the forums on<br>
> > <a href="http://www.cnczone.com" target="_blank">www.cnczone.com</a> it's an awesome resource.<br>
> ><br>
> > Cheers, Me.<br>
> ><br>
> > On 30/06/11 22:23, Cass Jones wrote:<br>
> >> Is there a set of 3 or 3 similar 200 step motors in there by any<br>
> >> chance? I'm planning on making a circuit board mill as my next<br>
> >> project.<br>
> >><br>
> >> On Thu, Jun 30, 2011 at 9:42 PM, Richard Jones<<a href="mailto:rjtp@ihug.co.nz">rjtp@ihug.co.nz</a>> wrote:<br>
> >>> In reply to Mark Becket I have appended photos of the stepper<br>
> motors to our<br>
> >>> last meeting pics located here:<br>
> >>> ChchRobotics2011June20 | 113134050398543502524<br>
> <<a href="https://picasaweb.google.com/113134050398543502524/ChchRobotics2011June20?authkey=Gv1sRgCLH0yquZjd6hVA&feat=directlink" target="_blank">https://picasaweb.google.com/113134050398543502524/ChchRobotics2011June20?authkey=Gv1sRgCLH0yquZjd6hVA&feat=directlink</a>><br>
> >>> The motors were kindly donated by Chris Hellyar when he was tidying up<br>
> >>> around last February.<br>
> >>> I also have a few NiMH AA cells if people want those for<br>
> robots. I'll bring<br>
> >>> these items to our next meeting on Monday 20th July 2011.<br>
> >>><br>
> >>> Richard<br>
> >>><br>
> >><br>
><br>
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