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I continued to work on making die blocks today. Thought I was done. Then I remembered that I needed to make another set for the Octagon 100. I want to put the S-7 combination dies back on the shelf for safe keeping and to replace them with 4140 pieces. So as I was cutting the bandsaw blade finally wore out. A good excuse to run into my machine shop supplies boutique. Getting out of the shop can often lead to a fresh viewpoint, but today it didn't make a bit of difference. I drove past one of my steel suppliers and was tempted to stop in and order a proper size cross section billet, but didn't because I simply want to use up the odd ball pieces I have and be done with it, economy be damned. Pure stubborn-ness.
Someone asked me about whether the exhaust air pressure could be somehow re-used. What I told him was that my air hammers are controlled by back-pressure so that anything that increases back-pressure slows down the hammer. In contrast, locomotive steam engines eventually became triple expansion versions for increased efficiency. Steam is an expanding gas and that is why it works; the exhaust of the first cylinder feeding the second cylinder and then exhausting into a third. On my hammers, it is possible to use the pulses of exhaust air, for example to feed air into a coal forge, but feeding them back into the hammer won't work.
Can a utility hammer be controlled by a throttling input valve with an open exhaust system? Sure. I've tried it and I know Steve Gensheimer does it that way on his shop made hammer. He's a very savvy designer so that he surely had his reasons. I've tried it but that was long ago and then I thought the machine was not as responsive as I like at light treadle.
I got to thinking about this today while standing at the mill. And I thought about the Mike Linn idea from the 90's (check out the Alabama forge council web site, perhaps) to use differential inlet pressures on the cylinder, more pressure being used on the piston bottom to give greater lift to fight gravity and to counter the smaller piston area caused by the cylinder rod. With an open exhaust and very little back pressure the tup drops like a rock. With back pressure it won't. And with enough pressure differential on the up-stroke the tup will seem to have buoyancy.
Ain't this fun? :-)
Someone asked me about whether the exhaust air pressure could be somehow re-used. What I told him was that my air hammers are controlled by back-pressure so that anything that increases back-pressure slows down the hammer. In contrast, locomotive steam engines eventually became triple expansion versions for increased efficiency. Steam is an expanding gas and that is why it works; the exhaust of the first cylinder feeding the second cylinder and then exhausting into a third. On my hammers, it is possible to use the pulses of exhaust air, for example to feed air into a coal forge, but feeding them back into the hammer won't work.
Can a utility hammer be controlled by a throttling input valve with an open exhaust system? Sure. I've tried it and I know Steve Gensheimer does it that way on his shop made hammer. He's a very savvy designer so that he surely had his reasons. I've tried it but that was long ago and then I thought the machine was not as responsive as I like at light treadle.
I got to thinking about this today while standing at the mill. And I thought about the Mike Linn idea from the 90's (check out the Alabama forge council web site, perhaps) to use differential inlet pressures on the cylinder, more pressure being used on the piston bottom to give greater lift to fight gravity and to counter the smaller piston area caused by the cylinder rod. With an open exhaust and very little back pressure the tup drops like a rock. With back pressure it won't. And with enough pressure differential on the up-stroke the tup will seem to have buoyancy.
Ain't this fun? :-)
