Thread: Air hammer?

Also, does anyone know whether a pneumatic tie rod actuator is too wimpy for this? They have something at Princess Auto that looks like it may work.

First off, I've never personally built an air hammer. I have a working hammer I'm happy with. But smiths talk about such things and this is what I remember.

The original Kinyon design and all the subsequent variations, are really air powered treadle hammers. One blow per push of air. They consume air so think about having enough air supply, e.g. a storage tank of some sort in-line because I've seen these things suck a compressor tank down to nothing in a short working time (shorter than the demonstrating smith wanted to get work done).

Discussion, criticisms of that kind of operating system arise from those of us who want to stay on the hammer while the steel is still hot.

https://www.youtube.com/watch?v=L5IIuhCbNto

The above video illustrates an air circuit that recuperates air. Aside of not wasting so much air compressed, it also allows the operator to "feather" the blows, increasing control over the power of each hit and the resultant cushion at the end of the downstroke pushes the tup back into recovery ready for the next stroke. It also means that the power of the downstroke is not beating the bottom seals out of the cylinder or the anvil and then reflecting back into the upper parts of the hammer. It allows for rebound upward. This is the primary type, maybe not an exact match, for the working parts of Beche, Nazel's, Chambersburg and other old style power hammers.

The bigger the falling weight, the bigger the anvil, so pay attention to any required mathematical relationships recommended for any power hammer about that ratio. The bigger the falling weight, the relative increase required in the moving parts as physics strictly applies. Every action means reactions at the same power. You don't want your hammer beating itself apart because of the absence of stout. I think this is why we are all card carrying members of Over-Engineers-R-Us.

Hopefully some of this will help.

Huge thanks!

I have looked at lots of the Kinyon stuff etc but there is good information strewn everywhere. Thanks for this!

The valve I have looks like a 2 position 12 v solenoid actuated valve with spring return and pilot actuation. I'm going to have to noodle on a control system to use what I've got.

Found a 'latching relay' on eBay and should have a plan soon.

One more question: does anyone here use an air/hydraulic press for Damascus billets? I may delay the hammer build if I can press billets with a 6-ton air/hyd press for now. Clearly the hammer allows more/different work.

The press I am looking at is an a-frame air actuated bottle jack type from Princess Auto (similar to Harbour Freight).

Originally Posted by Atchbo

One more question: does anyone here use an air/hydraulic press for Damascus billets? I may delay the hammer build if I can press billets with a 6-ton air/hyd press for now. Clearly the hammer allows more/different work.

The press I am looking at is an a-frame air actuated bottle jack type from Princess Auto (similar to Harbour Freight).

All the recommendations I've seen have been for 20-ton+ presses for that kind of work. I have been thinking of looking into an air over hydraulic press too, so am also curious about what others will say.

BTW I think Princess Auto have their 20-ton air/hyd jack on sale at the moment. Maybe fitting that into a 20-ton press and selling the hydraulic-only jack that comes with it might be an option?

I know they aren't ideal, and a proper 2 hp two-stage hydraulic system is preferred. Also, air/hyd is slower and can draw out the heat etc, but it's a potential solution for my hobby at a price I can afford.

I just know from my limited experience that metal is some hard sh!t, even when hot, and I'm not sure whether 6t is enough. I might make a fullering die to make best use of the pressure and hand forge the rest.

Originally Posted by Atchbo

I know they aren't ideal, and a proper 2 hp two-stage hydraulic system is preferred. Also, air/hyd is slower and can draw out the heat etc, but it's a potential solution for my hobby at a price I can afford.

I just know from my limited experience that metal is some hard sh!t, even when hot, and I'm not sure whether 6t is enough. I might make a fullering die to make best use of the pressure and hand forge the rest.

From my *very* limited experience (1 billet!) the part of the process where the press would be most useful would be in drawing out. The actual welding doesn't need all that much in the way of whacking/pressure. But drawing the thing out was a hell of a lot of work. Even if it was just fullered in a press and then finished by hand, much effort would be saved. So my thoughts are almost identical to yours: it would make a relatively cheap option to help in drawing out.

Another concern for me is that I don't have the biggest compressor in the world, so part of the savings would likely have to go straight back into a bigger/better compresser. Which then gets me thinking about building a proper hydraulic press. This is exactly the kind of thinking that explains my current financial situation, which in turn explains why I can't just go buy the press in the first place.

Hmmm... air/hydraulics look pretty wimpy/slow... and this vid is a 20 t press.