[TheForge] power hammer

[Andy Vida]

Ralph Sproul wrote:

> My initial thought was the differential would have some serious drag to it
> for a 1HP motor.........did it work well or was it sluggish due to this?

	The hammer, as I recall, worked very well and appeared to be
	very responsive.  When I say I was very impressed, I meant
	that as an all around qualifier.  I think this would make a
	very good basis for, say, a kit hammer.  Use of an axle out
	of an old drag car (shortened) would decrease the footprint.
	The differential would probably last more than a lifetime even
	with heavy use.

> Are they running the electric motor into the drive shaft end with a
> coupler - then using the differential as the clutch and drive? or do you
> need a jack shaft to cut the motor speed to something usable on the output
> end of the differential?

	I'm not sure I recall.  There may have been a jack shaft.  Anyone?

>  A 1750 motor cut to 4:1 ratio speed is still in
> the 400 RPM range - so I'm not seeing how they are accomplishing a running
> speed unless they slip the brake thru the whole operation?

	Well, if you find a diff with, say. 5.88 or 6.12 gearing
	(again, from an old drag car or street rod)

	5.88s would give 297 bpm, whic is right in there.  6.12s
	produce  285.  You could even use an old truck axle with
	11.xx or lower for a heavier and slower hammer.
	
	This solution leaves you with comparatively little work
	because almost all the precision work is done for you.
	Find a suitable guideway, and you're good to go.  I
	was thinking that the cross slide from, say, a 20"
	swing or larger lathe might provide a superb basis
	for a ram and guides.  It is dovetailed and complete
	with gibb adjustments built in.  The dicey part is
	welding to the cast iron, and that's not so hard if you
	take your time.  If you machine your linkages with
	good accuracy so as no to load the ram in the wrong
	directions, I see no reason why a well maintained
	hammer should not last as long as a factory made specimen.

	Another great guideway would be a box-type bedway from a
	large junked CNC mill or a dovetail way from a CNC lathe.
	They are precise and very strong.