Homebrew PCBs

--- In Homebrew_PCBs@yahoogroups.com, DJ Delorie <dj@...> wrote:
>
> 
> http://www.delorie.com/pcb/dremel-stand/
> 
> My big drill press has too much runout for the tiny drill bits, and my
> hand isn't steady enough to drill manually with the dremel.  So, I
> made something simple that would just hold the dremel steady so I
> didn't snap any more drill bits.  I drilled a couple of 13 mil holes
> with it, seems to do the job (although there's some runout even still,
> partly due to the bits vibrating).
>

Another great example of simple woodwork providing an elegant solution. 

The design, heavy dremel on the end of long flexible arms, is going to 
show vibration components but there are techniques to try that may 
dampen them. 

Assuming the dremel is a snug fit it the arms, I would try the mass 
weight technique used to stop flutter on aircraft control surfaces. 
Bluetac a large-ish lump of steel just behind the dremel on the lower 
arm and see if a large mass here will dampen the vibration, at the 
drill speed you need. This weight may bend the lower arm and this may 
attempt to set the dremel free so tape the arms together for the 
experiment.

Once the weight gets up a bit you may need to arrange a counterbalance 
for the weight. Perhaps fit a bungee from the top of the uprights to 
the area the weight is sitting or alternatively temporarily install 
some compressible rubber between the lower arm and base board.

All the best, great job.