[TheForge] power hammer

[Andy Vida]

Ralph Sproul wrote:

> Pretty much the hardest thing to build on a mechanical hammer would be a
> good mechanical friction clutch.  Anyone know of a good mechanical clutch
> and not air, electric or magneticly operated?

	Clutch configuration is a pretty simple affair in principle.
	If we're talking about building one from scratch, there
	would be a good bit of machining involved.  A conical affair
	is common enough.  They provide very good lockup, progressive
	action, and good release with low thrust loadings, as opposed
	to a flat plate affair (like an automobile clutch) that needs
	far higher pressure to lock up, or multiple plates which
	greatly reduces control (ever ride a three or more plate clutch,
	they are either full on or full off with little in between).
	One exception to this would be a motorcycle clutch, so perhaps
	a unit out of an old junker (750 Honda?  Harley?) would work,
	but you'd still probably have a good bit of machine work between
	you and a working mechanism.  With a good long treadle, the
	spring pressure might be OK.

	Anyhow, I like cone clutches for such applications and many
	of the hard-mechanical hammers use them.