This is what I was experimenting with.
Left illustration was a temp set-up clamped on the table to compare impact / mass / return spring relationships.
I only used 1/4" valves and tubing, so easy enough to go bigger if necessary.
It had a surprisingly heavy wallop. I'm making 2 new cutter blocks to verify by actually cutting some sample material.
On the right is what I thought I would put together.
The outer tube will be a surplus steel hydraulic cylinder.
Threaded cap on the top for the air fitting.
The weight itself will have a groove with an o-ring or lip seal.
The spring connecting pin will pass through the weight and through 2 opposing slots in the outer tube to
prevent rotation of the weight keeping the upper cutter block aligned.
The springs will only be heavy enough to reliably return the weight to its upper position.
The position of the exhaust ports are positioned to allow the hammer to return the blocks to the open position instantly, with no interference.
A special quick exhaust valve might not be necessary at the inlet port as there will be 5 seconds or more before the next cycle.
See anything that could use improvement ?
This is the least complex solution so far ( I think)
Will be searching for the recommended metal and treatment for the cutter blocks to withstand the beating. The cutting edges aren't the major issue, it's the flat parts of the blocks that slam together that concerns me.
Still tryin to draw like Ian .... some day.
Thanks folks,
Russ