[MARTINSR]

Randy, I have a couple of these Michigan Pnumatic planishing hammers. It has this "knob" on it right behind the body on the "handle", what the heck does it do? I have turned it one way and the other and it doesn't seem to do a thing. It has sort of a "saw tooth" at the bottom so you lift up slightly and turn and then let it go back down in a new position.

[Randy Ferguson]

Hi Brian,

It should just limit the travel of the trigger. I don't believe it has anything to do with air pressure. For optimum performance, you should have an air regulator added. Just a small valve to throttle the air volume would be sufficient. For shaping, you run it fairly loose and for planishing you run it tight. That knob should be directly related to the amount of pressure you can place on the dies. Full trigger pull should hold them tightly together, but if you turn the knob out a couple turns, it should hold the dies at a few thousandths separation.

If you run across any more of those, please let me know. I would be interested in a complete unit, or just the air motor.

Randy Ferguson

[MARTINSR]

Thanks Randy, I'll go out and play with it over the weekend to see how it works. I have a photo and copy of a brochure of a floor mounted unit I plan on making. The "motor" simply installs on it the same as it does on the frames pictured.