travel needed for a KAZ75 type striking hammer

[basher]

I have wanted to make some kind of power hammer for some time now , But Being in the Uk I have always found it cheaper to buy old hammers.
I have a 60lb goliath and 150lb herculies (+300 alldays in the yard waiting.....)

Currently I have a job which requires a very precise one blow striking and I was thinking that a single blow Ka75 type hammer would be perfect .I have been getting a friend over to do the hitting but think a purpose made hammer would be better .
I Have 2 80mm air cylinders with 250mm travel and was wondering if this was enough distance to get the weight moving or if more Travel was needed .
what weights could I run with twin 80mm cylinders ?
I think a striking hammer would be a great addition to my stable .
My other thoughts are that air supply is greatly limited by hose size and that onboard air cylinders with larger ports would speed up the hit quite a bit .
any thoughts would be most welcome .

[Bentiron1946]

This is an alternative to buying another hammer

B)

[youngdylan]

I have wanted to make some kind of power hammer for some time now , But Being in the Uk I have always found it cheaper to buy old hammers.
I have a 60lb goliath and 150lb herculies (+300 alldays in the yard waiting.....)

Currently I have a job which requires a very precise one blow striking and I was thinking that a single blow Ka75 type hammer would be perfect .I have been getting a friend over to do the hitting but think a purpose made hammer would be better .
I Have 2 80mm air cylinders with 250mm travel and was wondering if this was enough distance to get the weight moving or if more Travel was needed .
what weights could I run with twin 80mm cylinders ?
I think a striking hammer would be a great addition to my stable .
My other thoughts are that air supply is greatly limited by hose size and that onboard air cylinders with larger ports would speed up the hit quite a bit .
any thoughts would be most welcome .

I Built a KA style hammer not that long a go. Initially it was a tap on the treadle per blow but I rigged it up witha pilot circuit so it would auto cycle. The tup is somewhere around the 50 kg mark and its's got about 450kg of anvil and base. I use 2 x 50mm cylinders with 250mm stroke. Works fine but would have liked to use 320mm cylinders but they would have pushed the height up too much or I'd have had to bore out longer guides

I bored the ports out on the cylinders from 1/4 BSP to 3/8 BSP and used the shortest fattest hose I could. Especially important on the exhaust side .

I now have this just an autocycle hammer but have rigged my other Kinyon up so it will autocycle or give very repeatable single blows using a pneumatic pulse generator. More info in this thread

http://www.iforgeiro...ka75ish-hammer/

[youngdylan]

... forgot to say, if you just need single hard blows and aren't bother about lifting speed then 2 80mmm cylinders will apply a total lifting force of about 700kg at 7 bar pressure..... you could use a pretty big tup !!!! (as long as you'd got a good sized anvil) .... With single blows a slow lift up is ok. When striking you'll have downward aceleartion due to gravity + force of 600kg due to downward air pressure. The longer the stroke, the more the tup acelerates and the more enegry it picks up that can be transferrred to the blow. Speed is imporatant because the energy is proportional to the square of the speed.

My gut reaction (based on my smaller scale version) is with around, say 500kg of anvil mass, it's not really worth going above say 100kg tup. This weight with 80 x 250mm cylinders should work a treat. You will be flowing a lot of air and will need a pretty big valve with at least 1/2 BSP ports, maybe even 3/4 BSP if they are readily available/not too expensive. More height would be good if you're using tall tooling.

Whereabouts in England are you? I'm in Manchester and you're welcome to visit my workshop too see my set up.