Re: [CAD_CAM_EDM_DRO] Re: taig pick and placing

Graham Stabler wrote:

> --- In CAD_CAM_EDM_DRO@yahoogroups.com, Jon Elson <elson@...> wrote:
>
>>When I wanted to build a P&P machine, I didn't
>>think speed was important. But, this machine is SLOOOOW!
>
>
> I often get hypnotized by watching CNC machines but this might put me
> in a coma. Still it obviously got the job done.
>
> It sounds like you have yourself a brilliant set up now, when I have
> to widen a door for a piece of machinery I'll know I've arrived :)
>

This was almost a catastrophe! First, I had great trouble
locating an affordable double door set, several places quoted
3-4 weeks delivery and/or price over $1000.

I thought about doing it myself, but decided to at least get a
contractor to quote on it. The first guy wasn't going to do it
the way I thought it should be done, the 2nd guy did, but it
made the job harder. He is a massively built guy, looks like a
not-very ex marine, only more muscular! He rented this enormous
concrete saw. It looked like an industrial logging chain saw
engine with a wheel-shaped diamond blade. It cost $400 for the
machine, plus $400 for the blades he burned up. He was totally
wiped out by having to stand on a scaffold and hold this huge,
bucking saw in the concrete, and it took all day! I would have
died!

> Very interesting use of etched solder stencils and I definitely agree
> on the cleaning front, I think an abrasive is useful as it provides a
> key for the film resist to fuse into.

Well, I have only made 2 sets of stencils so far. The first one
was made from .005" shim stock that came in a "book" of all
different sizes. Then, I bought a roll of the .005" material,
but it might be a different alloy, and didn't etch well at all.
I may have to experiment with it a bit to find out if cleaning
is the difference, or if I need a different alloy stock or
different etchant. It also may be that a thinner shim might
work out better, as I have been getting too much solder paste on
the pads, especially the fine-pitch stuff.

I can also just etch some test scraps to see if they etch
differently.

Jon