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75mm Locky Kazoo (say that 10 times fast)
Posted: Fri Jan 09, 2004 10:39 am
by Mike Everman
Enjoying myself on this one. It took 1.5 hrs to get the engine fully crushed, including making the tooling. Can't expect it to run with that little effort, but it shouldn't have any pinholes!
CC dia is 75mm, over-all length something like 1200mm. material thickness, 1mm (more precisely: .045")
some whacky geometry happens when you have nothing inside when crushing. Unexpected waves make it interesting, and bring some dimensions into question, but oh well. I have everything to make it go this weekend, wish me luck!
Posted: Fri Jan 09, 2004 10:42 am
by Mike Everman
more...
Posted: Fri Jan 09, 2004 10:43 am
by Mike Everman
and more...
Posted: Fri Jan 09, 2004 11:03 am
by Stephen H
75mm Locky Kazoo, 75mm Locky Kazoo, 75mm Locky Kazoo, 75mm Locky Kazoo, 75mm Locky Kazoo, 75mm Locky Kazoo, 75mm Locky Kazoo, 75mm Locky Kazoo, 75mm Locky Kazoo, 75mm Locky Kazoo ... :) looks cool!!
Nice work.
Posted: Fri Jan 09, 2004 11:29 am
by Graham C. Williams
Dear Mike.
I'm sure your maths is correct, but I can't help the feeling that the exhaust and induction holes look too small. I can only put this down to my mind wanting to interpret the 2D pictures with circular symmetry.
Anyway, I look forward to hearing what happens when you flush some meths through the pipe and light it. Try and make a (low distortion) recording for us. If you want any advice in this last respect just ask.
Good luck.
Graham.
Posted: Fri Jan 09, 2004 2:02 pm
by Viv
Oh I just love that rig! are they really fork lift truck extension legs?
Viv
Posted: Fri Jan 09, 2004 4:17 pm
by Mike Everman
Oh I just love that rig! are they really fork lift truck extension legs?
Why yes they are! With two holes added. Worked well, but the sections sprung back somewhat; I'm leaving them fat for now.
Posted: Fri Jan 09, 2004 7:00 pm
by Mike Everman
75mm Locky Kazoo, 75mm Locky Kazoo, 75mm Locky Kazoo, 75mm Locky Kazoo, 75mm Locky Kazoo, 75mm Locky Kazoo, 75mm Locky Kazoo, 75mm Locky Kazoo, 75mm Locky Kazoo, 75mm Locky Kazoo ... :) looks cool!!
No fair using "copy" and "paste"!
Dear Mike.
I'm sure your maths is correct, but I can't help the feeling that the exhaust and induction holes look too small. I can only put this down to my mind wanting to interpret the 2D pictures with circular symmetry.
Anyway, I look forward to hearing what happens when you flush some meths through the pipe and light it. Try and make a (low distortion) recording for us. If you want any advice in this last respect just ask.
Good luck.
Graham.
Here is the dimensional calc output, look at "t outside" column, you see the exhaust throat gets squeezed down to .285".
Assumptions are that it squeezes with straight faces of length "ctrs", with half cylinders at each end (niether of which actually happen, but it's a starting point), and that the circumference is constant.
So the Throat outside dimension minus material thickness is .195, the area then coming out to: "oh crap, I have to check my spreadsheet!!!"
It's right on how thick, but wrong on how wide "ctrs", which is a derived column.
Posted: Fri Jan 09, 2004 7:56 pm
by Mike Everman
OK, fixed. It was calculating the squeeze right, but an "area check" column pointed out that the "ctrs" dimension was off. I'll include also the drawing this is based on...
Posted: Sat Jan 10, 2004 12:43 am
by Mike Everman
Some more photos. Buffed her out today. CC is 75mm dia, aint she purdy? Real organic. I'll try some meth in it tonight, I got a spark unit from a stove repair shop, and everything for propane feed, but I need to weld the spark and fuel ports monday. Hope to make some noise by Tuesday.
Posted: Sat Jan 10, 2004 12:51 am
by alex
Mike, which pjet is it?
Alexander
Posted: Sat Jan 10, 2004 1:03 am
by Graham C. Williams
Dear Mike.
Run the meths through the motor before you fit spark and fuel feed.
Locating the correct place for fuel injection is important. If your not sure I can send you details.
Graham.
Posted: Sat Jan 10, 2004 2:26 am
by cudabean
Mike,
Cool looking divergence on the exhaust. Good luck!
cudabean
Posted: Sat Jan 10, 2004 6:31 am
by Mike Everman
IT PULSATES!!!!!
A pool of Methyl Alcohol in the combustion chamber, and a hair drier in my garage, good times! Of course, I have no hair on the back of my hand anymore...
Graham, I'll attempt a recording, but for now, it sounds like: "whoosh! loodle loodle loodle" ;-P
Posted: Sat Jan 10, 2004 6:41 am
by Mike Everman
Mike, which pjet is it?
Alexander
Alex, it is equivalent to a Lockwood with a 75mm diameter combustion chamber, only a bit simpler to make!