By: Dave Hammer
Hammer and Guide
The hammer guide is a heavy walled 4x4" square tube. I drilled 1" holes where all the little pipes are, then welded short pieces of 3/4" black pipe over them. The short pieces of pipe have 3/4" nuts welded in the ends near the outside edge (weld these in first). A half inch bolt, with a locknut is used to push a brass rod that fits neatly into the pipe. I cut the heads off the bolts and cut slots so I could use a screwdriver instead of a wrench. I used small furniture gliders (those that you can buy in hardware stores for putting on the bottom of furniture) as the bearing against the hammer. The gliders are 3/4" round nylon of some type with a washer backing. I have used larger versions of these to move very heavy equipment across concrete floors. The size I bought came with nails to put them on the bottom of chairs or furniture, but I bought small machine screws (bolts) and tapped into the brass rods to hold them on. They work very well for bearings.
I loosen all the bearings up, put the hammer down, aligning it with the 1" bar in the die holes, then lightly tighten the bearings against the hammer so it is centered in the guide, then lock the nuts. I spray silicone on the hammer, and it works easily up and down. The bearings have a rubber backing, so they have a little give and must occasionally be adjusted.
The hammer is a rod from a giant hydralic cylinder, but I'm sure a regular smooth 3" round bar would work. My bar was actually scratched a lot and I sanded it smooth.
Obviously, any hammer and guide setup could be used instead of what I fabricated.