diytube.com

After about a year of procrastinating, I
am going to build my st70 clone, but
I need a chassis. My boss has a
metal shop and offered to build one
for me. However, I cannot find a
template of the st70 chassis or
even the exact dimensions for the
various slots, holes, etc. on the
chassis. Does anyone know if
such a template exists?

I could measure and draw plans
to scale for the chassis, if only
I could draw a straight line...

Have you though about a two step process ? In other words,
have the chassis made, then use the parts as templates.
Lay the tube sockets on the chassis, the circuit board, the
transformers, etc, and mark the spots with a Sharpie and
indicate the hole sizes. The layout is totally non-critical.
The tube socket hole sizes will depend on what sockets you get.

Take a look at some of the amps I've built - they were all
done on the kitchen counter with hand tools.

http://mcnally.cc/amps.htm

I envisioned a one-step process. He
has a full metal shop and I don't even
have a tapered reamer! We do not
know what material the chassis will
use, but are leaning towards stainless
steel.

My boss is not a tube guy, so he wants
exact dimensions. He'll also be making
punches for cutting out the holes for
the tube sockets. There was also
some talk that if a different material
were used, he would copper-plate it,
which would be beyond awesome.

You could still use the template method on a piece of cardboard. Lay the parts out and mark them, then get some assistance if you need to turn it into what he wants. You don't want to cut any holes until all parts are in hand and verified. It's pretty easy. I haven't seen a template for an ST-70 anywhere, but it's pretty simple.

I think I'll get a rust bucket of an old
st70 chassis. I could send it to him,
or make a template out of it and
send him that. I only need the top
part templated, as the stupid
slide-switches and jacks on the
front and back must go.

Maybe he could copper-plate the
rust bucket while he's at it.

I built an ST70 and had the chassis bright copper plated.
http://home.earthlink.net/~mikesherman/ ... ST70-4.jpg
It is definitely worth the effort.

A rust bucket chassis won't take to copper plating too well, the metal in all likelihood will be too rough. However, painting a "rust bucket" can turn out quite well, just look at Shannon's 6V6 amp on "the rustiest ST70 chassis of all time" posting:

http://www.diytube.com/phpBB2/viewtopic ... hlight=6v6

/ed B in NH