[TheForge] Krause/Nazel type air hammer

Tue Dec 3 22:55:01 2002

I concur with Bob Schade's comments. I did not see Mark's hammer operate so
if you have, please comment on the crank and connecting rod in terms of
noise and vibration.
The valve is important , but the mechanical power transmission to the work
cylinder may be the achilles heal for the home built model.I hope not, but I
hope to find out soon.
Bob

----- Original Message -----
From: <[email protected]>
To: <[email protected]>
Sent: Tuesday, December 03, 2002 11:12 AM
Subject: RE: [TheForge] Krause/Nazel type air hammer

> 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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