[TheForge] Krause/Nazel type air hammer

Tue Dec 3 21:03:00 2002

correction...3" (connecting rod) should be 3'. i could live with 3".

bob

andy,

i thought of that too. in fact i bought 2 three way ball valves from mcmaster carr. i still think it might work but i was dissuaded by someone. the problem (they said) was that the valves don't open progressively. that is because the opening in the valve isn't a straight sided opening like a square or rectangle. it starts opening with just a little crescent and then goes from there. you can visualize better than i can describe (i hope).

i think a better and just as easy solution would be to make (as mark describes in his booklet) two three way spool valves. i think it's doable by most.

just drill the hole undersize, ream about .0005 undersize, then lap your spool to a nice fit. go to your engine rebuild/hot rod shop for help on lapping as they do it all the time (or used to) when lapping valves. mark shows the spools being made by filing or grinding (bench grinder) the openings in them.

this is all a moot point as far as i'm concerned so whether it could be done or not is still debatable. i am a machinist but if you're not and you need machining done there are guys out there that will do it by the hour.

what turned (!) me off to the whole krausehammer project was this. marks hammer hits 305 beats per minute. light blows are 305 bpm, hard blows are 305 bpm. this means that the double ended (pump) cylinder is stroking at 305 strokes per minute. as bob smolen mentioned earier the pump cylinder is connected to a crank. the connecting rod would be 3" long (the longer the better in order to lessen the side load on the pump cylinder) and going around at 305 rpm.

when i work on a project that will need some power hammer work i turn on my 25 LG and just leave it run. all day, a few hours, whatever the project needs. the whole time it's running it's a 1horse motor just sitting there idling. no long shaft moving at 305 rpm. when i need power i step on the treadle and use it.

with the krausehammer would you leave it idle and have all the hardware (connecting rod/pump cylinder) stroking away? maybe so. i think mark mentioned once in an email that he turns his on and off.

in the end it seemed like i would end up with a hammer (if it worked) that maybe had better control but also had a downside (to me). it just didn't seem worth all the trouble to me. why not buy an aircompressor that is made to pump air and build a kinyon?

having said all that if bob smolen or you or ? get one working and it works good i'd be the first in line.

i'll shut up now.

bob
______

>I decided not to build one of these because of how much time I don't have,
>but after gazing at Mark's book and my sketch pad for hours, I concluded
>that the job could be done by a linkage that activates two ball valves. One
>opens as the other closes.
>Times two, of course, for upper and lower air passages.
>Get the proportions of the levers right for the treadle travel, and you've
>got it with components you can buy at Ace Hardware.
>Simple, huh?
>Not as cute as Mark's, but it would work.
>
>Andy G.
>
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