Elektra I Jet Engine Builders Web Log

This Web log is to encourage building and experimenting with the world's cheapest working pulsejet engine: the Elektra I(TM) - total cost in brand-new materials: Under $10.00 US, not counting the spark plug.

Want to build your own Elektra I pulsejet, with help from designer Larry Cottrill? Then this page is for you!

Friday, July 30, 2004

Congratulations! Nice Job, Steve ...

Steve -

Congratulations on getting her built and running! Thanks for going ahead with this, thereby giving me some independent verification of the workability of the design!

How in the world did you successfully thread a hole cut in a shell 1/16 inch thick? I almost fell off my chair when I read that one -- I would never have thought of even trying it with such thin material, except maybe in the case of miniature plugs like the H-2/V-2 size [tap size 1/4-32 NXF, exactly like a standard US glow plug].

Steve's photo of the spark plug, tap, nut and the threaded plug hole. The nut is not welded in, but threaded onto the plug as a spacer before threading the plug in place, keeping the plug from reaching ridiculously far into the chamber.

The thing I found fascinating when I read your post is the incredible number of things you approached differently ... but still ended up with basically the same engine and got it running on your first test session! I think that's wonderful, and is yet another part of validating the Elektra I as an easy-to build design: not only can we slop around some with the dimensions, but we can even vary the building and starting technique all over the place and still end up with a roaring pipe!

I can see that you got your intake positioned a little farther forward than I did [I mean, same angle but slid forward slightly] -- noting details like this is important: It tends to prove that my claim that dimensions aren't critical is correct. An important "selling point" of this design is that there are not supposed to be any critical dimensions, and your slight variations seem to bear that out. [Note: according to Steve's comments on the pulse-jets.com Valveless Forum, the only things he measured were the tailpipe length and the intake tube length -- the rest he just filed to fit, worked out to look like the pictures I posted on the Elektra I main site!]

Probably your most important variation is the completely different orientation of the fuel vapor delivery tube in relation to the intake. Your closeup of the front end of your engine shows the intake details [though you can't really see the angle at which the fuel pipe comes in]:

Closeup photo of the front end of Steve's Elektra I, showing his beautifully hand-formed sheet metal flare and the 1/4-inch steel fuel line entering the far side of the intake tube.

I have decided to create the Elektra I Powerplant Researcher Certificate for builders of the Elektra I engine from my design. Steve, in honor of your success in being the first ever amateur builder and tester of an Elektra I, I will be pleased to present to you the very first one printed, Certificate No. El-I-0001.

Steve, if you will privately email me with your full name [exactly as you wish it to appear on your award] and your complete home mailing address, I will see that you get your certificate, suitable for display. Please allow some time, since I still need to design and create this award.

Again, Steve, my heartiest congratulations!


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