[ Ref. 090510 MMDigest, "Seek Pouches for Ampico A Valves" ]

Hi Bill,  I was interested in your appeal for someone to punch out some
secondary Ampico "A" pouches.  If you have the right leather and have
done all the rest of the work of splitting the valves, etc., the pouches
are a "piece of cake".  I do not know what your mechanical abilities
are but I have sent along two pictures of how I made a simple punch out
of common steel plumbing pipe.

I knew that finding and buying a commercial punch that big might be
expensive so I just found the right size threaded union and turned it
on my lathe to a sharp edge.  I turned the outside straight to the
correct pouch diameter and tapered the inside at about a 30-degree
angle. (If you can't do this, perhaps you have a machinist friend!)
I think I then honed the edge with a sharpening stone.

The steel is not very good for this but with care and some occasional
touch up of the edge it easily lasts long enough to do a set of pouches.
This punch has already made two sets.

Hint: Don't tip the punch sideways when pulling it out of the wood
block, because it bends the rim.  Just gently tap sideways in a couple
of spots at the upper, nipple, end to loosen it from the wood.

Anyway, after making the punch I threaded a reducing bushing into the
opposite end of the union and threaded a smaller threaded nipple into
that so I had a small enough diameter face to be able to hit with a
hammer.  The exposed threads are covered with blue tape to protect your
hand.

The wood is an end grain piece that I got from a dead tree branch
in my yard and sliced into convenient length blocks.  However, it has
to be as fine a grain as is possible, with no soft spots.  Also, it
works best if you punch into the end grain rather than into the side.

This end grain face supports the leather and lets the punch penetrate
easily.  You can see all the concentric circles in the wood from
punching.  After a while the grooves of the circles cause the successive
leather pieces to not punch cleanly.  At that point, I merely re-face
the wood by running it through my power saw.

In use, depending on the size of hammer used, I had the best results by
alternately hitting the punch several times on opposing edges of the
hammering nipple face so that I wasn't trying to apply punching force
to the whole punch circle at once.  With experience you will learn how
much pounding is necessary to cleanly cut through the leather.

I hope this helps.
Pat DeWitt

 [ Thanks, Pat, I'll place the photos at the MMD Pictures Gallery,
 [ http://www.mmdigest.com/Gallery/Pictures/index.html  -- Robbie