I started this recently using scrap materials; tracked excavator hammer bit for the anvil, track excavator C frame welded together for the pillar, and a defunct weigh scale for the base. I may use a hydraulic cylinder for power by shop air, with a guided helve style envisioned. Funds are limited so it may take a while to complete.

So far so good.. 

I made some progress; the anvil is welded, as is the column and the brace between them (just tack welded in photo.) I need to source some more parts and start on the tup and air system.

I just put 1/2 down on a new air compressor to run my beast in progress....it is a Campbell Hausfield 5 hp 2 stage  with 80 gallon tank rated at 17 cfm at 175 psi. I will put it in after the first of the month when the eagle flies and I make space in the shop and make a new circuit for it.

Made some more progress; working out the geometry of the moving parts...

Making good progress.. Good to see.. Good stought materials as well..  Will the ram/tup be able to come apart once finished? UHM bearing?

Will it use a pull motor or a cam?  I'd guess pull motor or rods on a round plate.. 

I went with fixed dies on this project, and the ram is not able to come out without surgery due to unanticipated geometry. If it needs to come out I will have to cut off the die to remove it. The bearing material is polypropylene from kitchen cutting board, field expedient available material, and may have brass shims behind it if needed to take up space. I still need to drill and tap adjusting screws for the guide. I will be using a hydraulic cylinder powered by air to drive the hammer.

Very nice..  What made you decide to go with a leaf spring on the top though air operated vs just direct to the ram?  Auto adjust for height /thickness of material or Head height of the hammer? 

Mainly it was the head height; i didn't want the cylinder sticking up, and using available materials i couldn't figure out how to mount the cylinder and guide the head easily. It would have made the design more complex, and I also like the idea of the built in buffer action of the spring to cut down on excess vibration. Building without plans so hope it all works out

Looks good so far. will you have a toggle link for the top of the ram for the shift in the spring arch, to ram straight travel? 

The top of the ram has a set of rollers above and below the spring to allow for the arc of the spring as it reciprocates. Still thinking about the other end where the cylinder will be, if it needs the same arrangement or not. I might just arrange it with a pivoting connection at the cylinder rod end and connect it to the spring eye. Once i get the spring pack connected to the pivot axle and finish the guide box, i can do some unpowered experiments to see how it will work.

instead of leaving a gap for the spring on the head,  a toggle might be a better alternative as it will partially control the slap between up and down of the spring.. 

I had considered that idea, but all of the  hammers I have seen of this design had a similar arrangement to what i am using; do you have any photos or video of the arrangement you suggest in action?

Sorry, no I don't other than looking at a standard mechanical hammer with the toggles in place.. 

If the spring is pretty tight between the bolts with a rubber cushion I can see why it's not needed but if the spring is working directly against the top and bottom bolts/bushings I'm not certain on how it would fair.. 

If it turns out to be an issue, modifying the arrangement won't be difficult; i have used commercial air and mechanicals before, but this is my first try at building one. Hopefully i learned something as a mechanical type in the Army all those years ago and will be close on the first try.

Holes drilled for bearing mounts, and drilled and tapped for guide bushings....lead poured to fill the ram tube.

Compressor delivered today, rearranged the shop to get the compressor into its spot. Ram guides installed and alignment checked, so far so good.

Congrats..   You were doing great with pictures.. Now kinda stingy..  Pictures speak many words..  What did you get for a compressor.. Guides installed?? 

I will take some pics today and get them up later, didn't mean to get stingy....:) Compressor is a Campbell Hausfield 5 horsepower 2 stage with 80 gallon tank, 17 cfm at 175 psi. Need to plumb and wire it but that will have to get in line to be done.

Clarity not so good but shows the general idea....I cut off the die from the ram, melted in some more lead, then welded on a plate so the top die can be changed.  Guide bushings are drilled to index them and keep them in place. Bonus photo shows compressor AND my welding cart.

I  modified a spring bushing for the top roller to take up the slack and add in some rubber cushioning....yesterday i made the link for the top of the cylinder to the spring by modifying a leaf spring toggle, which i will beef up a bit by welding a strap on it; the eye of the leaf spring still has the rubber bushing in it, so it will be cushioned at both ends. I also welded on the top of the column, and cut a flange for the bottom of the cylinder to mount to. The cylinder and pivot point are placed asymmetrically so the rod does not extend to the end of its travel, so there will be a built in air cushion in the cylinder as well.

Keep them pictures coming..  I might copy what you are doing..  

Roger....good shop day today, finished up what i was working on yesterday.

great thanks..

Finally back to making some headway on this project; I wired up the compressor, had a flexible hose made, and ordered some air hose from Northern....also took apart the cylinder, reamed out the end cap port, cleaned, resembled and primed it. When funds permit, I still need to order the valves.