[TheForge] Air Hammer Cylinder and valve combination

[Don Sinclaire]

Mark:
I started building an air hammer a couple of years ago.  I used a surplus 12
inch by 2-1/2 inch cylinder and a surplus 5-way valve.  The Ram is about
15-20 pounds.  The ports on my valve are only 5/16 inch in diameter by the
time the hose barbs are screwed into the valve body.  Although the hammer
went up and down, it could not strike a very hard blow. I planned to use a
light weight ram and and depend more on speed than mass, since my anvil is
only 150 pounds.

It turns out that as the ram went down, it trapped too much air in the
bottom of the cylinder, so that air cushioned the blow at higher speeds.
The cylinder could not "exhale" fast enough. It worked OK if I reduced the
stroke to about 5-6 inches.  I then strapped a 14-inch piece of rail to the
ram to add weight and it started to hit harder, but slower.

I still check the surplus shop for valves from time to time, hoping to find
one with larger ports.  (A new one is a couple of hundred dollars.)

Since you are using a relatively large cylinder, make sure you get a large
valve.  You probably know more about that than I do, but I thought I would
mention that.

I would like to see a picture of the finished hammer.  Good luck.