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KZ150 Power Hammer build


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I am really not sure just how large a hammer one could make. I have this system working on a 30lb hammer, a 100lb hammer and now a 150lb hammer. Both the 100 and 150 are running on a 5hp compressor with 17cfm. This is a very efficient system. I think my controls could easily handle a 250lb to 300lb hammer but you would need a slightly larger bore cylinder and you might need a little bigger compressor.

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I am really not sure just how large a hammer one could make. I have this system working on a 30lb hammer, a 100lb hammer and now a 150lb hammer. Both the 100 and 150 are running on a 5hp compressor with 17cfm. This is a very efficient system. I think my controls could easily handle a 250lb to 300lb hammer but you would need a slightly larger bore cylinder and you might need a little bigger compressor.


Let me rephrase my Q. Assuming you would need twice the volume of air to run a 300, could that much volume pass through your controll an still run the hammer efficiently?
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John Nicholson, utility hammers and self contained hammers will use pretty much the same "silly" amount of air for a given amount of work. Square inches of piston area, pressure of the working air, length of piston stroke, and speed of piston movement pretty much make hammer physics what they are. There are no free lunches here.

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Hey John, I think that some poorly valved utility hammers exhaust at high pressure (ie, energy still in the the air as it leaves the system), and have issues with 'top piston air' and 'bottom piston air' fighting each other, slowing ram movement and thus reducing effective forging energy.

No free lunch, but more a case of eating whats in the lunch box thats given!

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Dan.C., give me a call sometime if you have any questions or if you ever get up here in the north country, stop in at our shop and take a look up close and try out a KZ100 or KZ150 hammer! I will be getting some video out in the next week or two as time permits.

Also, while I would have to agree that it takes a certain amount of air to move a cylinder up and down, I also believe that not all control systems are created equal. Some controls are just more efficient than others.

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Let me add a few comments intended to be totally positive, lest anyone think otherwise.

First of all Ken I admire your work, no doubt about that at all. When we spoke once on the phone months ago I remarked to that effect and to how you were one of the very few people who could claim extensive steam hammer experience and know in that way what you wanted to accomplish with your own variation of steam hammer valve linkage. Grant Sarver was my friend and mentor to some degree for many years. It was clear he respected what you have accomplished,especially given his steam hammer experience.

Secondly, I also respect John N who has been advisory to me and who I know has much experience with a wide variety of machines. I very much understand pros and cons of back pressure control. He has spoken to me via e-mail about his instrumentation to tune up industrial machines for higher efficiency.

Third, back in '96 or '97 I did experimentation on air-inflow-throttling versus air-outflow-throttling, and also using 3-position versus 2-position spool valves. My experimentation was undoubtedly less extensive than I would do today, but I learned to my satisfaction at that time that inflow-throttling gave me less snappiness and control than air-outflow-throttling. A friend uses inflow throttling but he too has less snap and control than he could achieve if he switched to backpressure Kinyon style throttling. So, Ken, your results are definitely eye opening and as an air hammer designer and steam hammer reverse engineer you get an "A+". I believe that the slotted arm in your spool valve control linkage has allowed finding a sweet spot for reciprocation behavior that my research could have certainly benefitted from 15 years or so ago.

Fourth, setting your air inflow valve to a constant position is pretty consistent with the constant pumping cadence of a self-contained hammer. It is a tuning feature given your linkage controlled reciprocation. That you are moving the linkage pivot up and down by treadle position obviously works great, though to call it throttling is not quite accurate. Actuation control, maybe is a better phrase. Even a self-contained hammer uses bleed off of pumped air--a form of back pressure controil--to throttle. Position of your manually adjustable pivot pin in the slot affects amount of spool movement and hence inherent reciprocation stroke length, air flow, and tup beats per unit of time. That is more stroke tuning than throttling, I guess.

Finally, I look forward to your reply.

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Let me start by saying “thank you” for the compliment, John.
In regards to your first question about exhaust air plumbing. Most of the air is dumped at the cylinder and the rest goes out through the muffler. I am not controlling the exhaust air as this system does work that way. As for your fourth item in your last post I am a little confused as to what you are referring to. I have been trying to attach a picture but I can't seem to get it uploaded so I will try to explain this way. The throttle is the valve small butterfly valve on the top left of the hammer, the directional valve is the valve behind the mounting plate (it has the muffler attached to it) and the control linkage is a combination of all the levers. Your reference to the position of the manually adjustable pivot pin in the slot affecting the amount of spool movement is not quite correct. The adjusting screw(the knob with the handle) does not change the length of travel of the directional valve, it changes the ratio (how fast it travels) compared to the rest of the linkage. Thus by moving the adjusting screw farther from the pivot point the hammer hits harder and faster. If you move the adjusting screw all the way toward the pivot point the hammer will not reciprocate as easily, it will act more like a treadle hammer. My “sweet spot” is about in the middle. I don't recall saying I throttled the hammer by moving the adjusting screw as that is done with the throttle valve.
I hope I have answered your questions.......ken

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Thanks for the reply, Ken. I know you are busy. But I'd like to learn a bit more. I still don't grasp why you need the dump valves given that the cylinder can exhaust through the spool valve exhaust port. My logic says the spool valve dump port ought to work without the dump valves. I suspect the dump valves are faster, but why is that important? Are there other reasons?

Thanks for the clarification about the spool movement extent versus its speed of movement with respect to the slot setting. I figured that when set all the way in the spool wouldn't move far enough to enable reciprocation, that is, the treadle hammer setting is not a reciprocating setting.

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Several years ago I built a pneumatic treadle hammer. Simple off the shelf cylinder and valve. Step on the treadle, the tup goes down; release the treadle, the tup goes up. It worked, but there was too much back pressure in the lines and the valve and the hammer was sluggish. So I installed quick exhausts to both ends of the cylinder. Doing that brought that hammer to life. Kind of works the same way with this system.

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Can I ask a couple more questions Ken ?
Isn't your valve a 4/3 center closed, in order to allow the tup to stop in 'treadle hammer mode' when you stop pushing the treadle further down ?
And when do you use the throttle valve ? I understand the need of a shut off valve but why don't you use the regulator in place of the throttle valve ?
Am I again messing up with 'flow vs pressure' stuff ?

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No, the motion of the tup is controlled more by the linkage than the directional valve. As far as the throttle valve, I have two settings that I use, a low and a high. The low setting allows just enough air to lift the tup and the high setting is wide open. The regulator just gives you some control over the throttle valve. Yes, you could use the regulator in place of the throttle valve but I find a combination of the two a better set up. Most of the time I run the hammer with the throttle valve in the low setting and the regulator pressure is set as low as possible that will still actuate hammer.

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