air_control

Update for April 14, 1998

I suggest the use of a 5 way valve instead of the four way because it does not require
feeding the air supply in reverse. Here is a list of some part numbers but there are many
other brands that will work.

5-Way valve - Versa VPP-5502 with 1/2" ports 1/8" pilots

4-way limit - Humphrey 41P with 34C rolling assembly

Flow control - Bimba FCP2K 1/8" ports

fitting & tube kit - Legris 31755311 1/8" NPT to 1/8" tubing (10 required)

The 5-way valve will hook-up just like our drawings except you don't hook it up in
reverse. The low pressure input is for the top of the cylinder and has the regulator on the
supply air.

The flow control connects to the normally open side of the limit and goes to the high
pressure side pilot on the 5 way valve.

I hope this helps some of you that are getting ready to build a hammer. If you are
scrounging parts the 4-way version works just as well but may not be quite as nice.

Good Luck,

Mark Linn

The dual pilot operation allows you to adjust the speed of the hammer with the
flow control valve. By adding this feature you give up some of your power but
you get a faster running hammer. By adding some valveing one could have it both
ways.

On my hammer the adjustment will actually turn the hammer head so fast it won't
even reach the dies before it's heading back up again. But with a short stroke and
open flow control you can get very quick hits. The 3 way limit has been replaced
with a 4 way limit so that you can operate both pilot ports on the main 4-way
valve.