And throwing in a few of yours ,
I've really enjoyed looking at shop built power hammers the last couple of years. Someone or a group will workout a good concept, prototype, bug it out and those inclined use it that way. Other eccentrics like myself perhaps get as much joy from the design/build as the use of it. The personal variations seem endless. The most practical would be to just save and buy one......no fun in that for me!
The concept I'm playing....err working on....
1) 35# to 50# apallachian guided spring helve
2) using the tire drive clutch idea (been done)
3) Replace the crank drive rod with an air cylinder for lenght adjustment, controllable single stike and some clamping ability. Not quite sure how the air cylinder will act in conjunction with the spring. Seeing a pressure feed to both sides of the piston which can be balanced. Seems endless combinations for action are possible. And if disappointed a drive rod will make a working hammer.
Guys like me always have a ton of possible refinements churning in the back of their head....Please feel free to throw yours in or punch holes as much as you like....it's all fun I'm new to digital pictures but will record the build (will even post them if it works!)
Thanks for any interest...Dave