Homebrew PCBs

Philip Pemberton wrote:

>In message <op.sum5c21pmg0lsf@tu-x2pj5qeyp2u4>
>          "Stefan Trethan" <stefan_trethan@...> wrote:
>
>  
>
>>I think the thought was to prevent damage to the main unit bearings (and  
>>increase in runout).
>>    
>>
>
>That was my thought - wreck the handpiece instead of the tool. Then again,
>the MultiPro 285 and the 225 flexible driveshaft are about the same price as
>far as I can tell.
>
>
>Photos of both on <http://www.tool-shop.co.uk/acatalog/Dremel.html>. I
>suspect details of the Dremel 220 will be on <www.dremel.com> somewhere; the
>manual for the Wolfcraft stand is on <http://www.wolfcraft.de/>, under
>Manuals -> Attachments -> Drill stands. Not sure about specs, but it claims
>to be suitable for a Dremel.
>
>Later.
>  
>

  The handpiece being a single width shaft will make it easier to 
modify.  Dremel expects you to use high RPM and only lightly load the 
tool, letting the RPM do the work.  Ball bearings will wear quickly if 
there is any real load with high speed and a small contact patch, real 
tools use roller or taper bearings, or at the very least large or 
multiple ball bearings.  Might take some looking but when it does get 
bad, you should be able to find roller bearings that would work.  Should 
also use a thrust bearing then, but could probably get away without it 
with the upper (still ball) bearing taking that load..

  I've looked at it before, but for what I do it's not really 
necessary.  Even if you didn't find an exact bearing, for non-hand use 
it wouldn't matter if you used a larger bearing and made a funky shaped 
adaptation for the handle.

  For mounting the Dremel itself, unplug, open the tool, drill holes in 
the case, and use nylon screws pointing out through the holes and nuts 
on the outside.  Your securely attached nylon screws are now sticking 
out to mount to, very easy to do a lot of different setups from that and 
you're reasonably safe with nylon.

Alan