Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

There are 40.000rpm brushless motors with water cooling and controllers
at less than 100eur from any RC store. But these small motors need
30-40A and so they can only run few minutes because they really heat.

Other brushless motors just give >1000eur and need an 1KHz 3 phase
controller.

Or modify and RC motor with more windings to work at 100V or more.
Wood plane seems nice for now. I don't mind to exchange the motor once a
year to make some boards...

But i am just someone with electric tools at home... not an engineer...


Stefan Trethan wrote:

>
> Personally i think a direct drive brushless motor is the way to go for
> these speeds.
>
> Also i think you need to pre-load the bearings to reduce runout. And i
> would select oil lubricated bearings over grease lubricated ones.
>
> I may be wrong i am not a mechanical engineer.
>
> ST
>
> On Mon, Jan 19, 2009 at 9:32 PM, Simão Pedro Cardoso
> <simaocardoso@... <mailto:simaocardoso%40gmail.com>> wrote:
> > Hi,
> >
> > Is very difficult to find a pcb spindle. Drilling a pcb hole of 0.5mm in
> > a FR4 laminate needs carbide tools and 50.000rpm spindle. This things
> > cost more than all other things to make a good CNC router.
> > I have found a away, but still didn't make/test the thing. From this
> > great sites (and thanks to them)
> > http://www.cnconabudget.com/dan_d.JPG
> <http://www.cnconabudget.com/dan_d.JPG>
> > http://www.buildyouridea.com/cnc/spindle_05/spindle_05.html
> <http://www.buildyouridea.com/cnc/spindle_05/spindle_05.html>
> > http://www.cncathome.com/spindles.html
> <http://www.cncathome.com/spindles.html>
> > http://www.students.tut.fi/~kontkant/jv2.php.html
> <http://www.students.tut.fi/%7Ekontkant/jv2.php.html>
> >
> http://members.home.nl/zoltar/CNC/classicsystem/10%20euro%20frase.pdf
> <http://members.home.nl/zoltar/CNC/classicsystem/10%20euro%20frase.pdf>
> >
> > I think to have found a way to do my 50.000rpm or more (i think i can
> > get 80.000rpm) pcb spindle.
> > Using this tool from ebay seller (he made the tool from my request!!)
> >
> http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=110329201156
> <http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=110329201156>
> >
> > And high speed skate bearing or better like this
> >
> http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=400000902567
> <http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=400000902567>
> >
> > And a AC brushed (universal) motor from a electric wood plane. It has a
> > 30.000rpm motor and a 2:1 or similar reduction that can be inverted to
> > give 60.000rpm, using the same timing belt and pulleys.
> >
> > Do you think it will work nice? I have made a circuit to pwm control the
> > motor speed. And i think if i give DC to the motor it will run in lot
> > more than 30.000rpm.
> >
> > I want to post the circuit online, but which cnzone forum pcb spindles
> > should go?
> >
> > Simao
> >
>
> __._,_.