air_hammer

The problem with the control system in the plans from ABANA, is that as a
pneumatic system, it is un-balanced. Our control scheme allows one to balance the system
and achieve maximum control, or un-balance the system when heavier blows are required,
with less hammer control. With the system balanced, one can lower the hammer head and
kiss the dies ever so lightly, or/and have a full heavy blow on the next cycle, or anything in
between. We offer this control system for those who wish to try it and I will attempt to
explain why and what we are doing. This scheme is working on a hammer, here at present
and is a beauty to behold. It actually does control like the European air hammers I have seen
in operation.

TRY IT YOU MIGHT LIKE IT…

This control scheme came from much aggravation, hair pulling, and yes a broken
foot. After many days of total exasperation trying to get good control on the hammer, I
contacted a pneumatic design engineer here in Birmingham. He offered to come by my office
and discuss the problem Jeff and I were having with our control scheme. With his guidance
we were able to come up with this design.

Problems:

The cylinder chambers are not equal. The cylinder rod takes up air volume in the
lower cylinder chamber and this alone causes an imbalance in the system. If equal air is
applied to the top and bottom cylinder at the center position, the top chamber will have more
cubic inches of pressure. To top this off we have the weight of the hammer head also pulling
down to create even more imbalance on the system. All of the simple air hammers I have
seen had very little control on the down stroke and it is obvious why, given the above
analogy.

Cure:

The simple cure is to control the amount of air allowed in the upper chamber,
compared to that in the lower chamber. By placing the regulator in line to the upper chamber
we can accomplish this, and there-by provide a method to tune the hammer to give us the
response we desire. With this control you can have a number of different settings depending
on the type work you are doing, chiseling, tooling, drawing, texturing, etc… .

Requirements:

The main requirement is that your 4-way valve be able to reverse flow. If you study
the control diagram you will see that we have basically inverted the control operation. Some
valves will not allow you to do this. Check with your valve manufacturer, ours allows this. All
else remains the same as the plans you get from ABANA.

Set-up

Adjust the pressure using the regulator that provides the air to the upper chamber of
your cylinder. You will find that it will be considerably less than the pressure coming to the
hammer. This pressure should be set so that the hammer head can be raised up past the limit
without falling while the pedal is not depressed. This appears to be the optimum setting.

If anyone wishes to contact me I will be glad to discuss it with you.

Mark Linn

Phone: (205) 987-2095 (evenings)