Homebrew PCBs

> > LESS total time if you take the time up front to build the proper 
> > tools ... the steel I used was a mill "cut-off" so it had 
> some ripples 
> > in it ... if the steel had been cut when the steel was cool, the 
> > lapping would be done in 30 to 90 minutes
> 
> > It takes about 10 minutes from room temp the first use ... I always 
> > allow the temp to over-shoot by about 20 degrees then set the steel 
> > block on a narrow strip of wood ... when the temp comes 
> back down to the
> > target   i use it ... the thermocouple is on the top of the steel so
> > there is a temp gradient across the steel
> > > So for double sided you just flip the board over afterwards?
> > >
> > I do one side at a time ... I spray paint side 2 .. image 
> transfer and 
> > etch side 1 ... then spray paint side 1 ... image transfer and etch 
> > side
> > 2 ... I do drill alignment holes for registration
> 
> Aluminum might be a better choice it conducts heat much better.
> I find it amazing that you actually built a motor for the 
> lapping and let it run for several days ;-)
> 
> ST


I built a similar rig to grind glass for a telescope mirror.  Doing it by
hand gets a bit boring after a while...

Aluminium would distort more (more flexible than steel), so you'd need to
make the plate smaller (small boards), or used a thick piece of metal, which
might take away the fast heating.

Still, the answer is now "Yes you can, got a big lump of steel handy?".

Good idea for small scale production.  I tend to do one-offs every so often,
so I'll stick with the printer fuser laminator.

Tony