Homebrew PCBs

On 6/21/07, Jim Hutchinson <jhutch17@...> wrote:
> If you are going to do a process several times, you will always spend
> 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