[TheForge] Air Hammer Guides

[John Newman]

I have finally started welding up my air hammer frame.  I just thought I
would get opinions on dimensions of my guides before welding that tube
to the rest of the frame.  Ralph Sproul and Shannell's  UHMW guides
seemed like a good idea so that is what I am building.  I have a 6"x1/4"
square tube that I have drilled and tapped to hold 18" of 1/2" UHMW.  I
am putting a 20"x 4.5" square tube inside.  The distance from the top of
the bottom die to the bottom of the guide tube will be 10", with a 2"
thick die this will leave 12" of bearing are at full extension, is this
enough? is the extension too much?  I am using a 12" cylinder to start
with, because I have one, but I am going to make sure it can be easily
changed  to a longer stroke.
I'm putting a hydraulic press on the back side of the hammer (another
idea taken from Ralph) I am thinking of using the same sort of guides
for the press.  Will they work? or are they even neccesary, would two
nesting tubes be enough?

John Newman