Please put your "I am new and need help" question here.

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JustinG
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Joined: Wed Oct 09, 2019 7:25 pm
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Re: Please put your "I am new and need help" question here.

Post by JustinG » Mon Oct 14, 2019 7:23 pm

Hey! I'm new and I need help.

I'm making a Lockwood pulsejet as my high school senior project and I need specific guidance. The actual design of the jet isn't the problem --I plan on using the Lockwood Patent design-- but I need help learning how to assemble it and where and how to buy/make all the parts.

For the actual jet I think I understand what to do for everything except the fuel injector, I've read up on the rosscojector but I'm not sure where I should put it.

Any suggestions?

metiz
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Location: Netherlands

Re: Please put your "I am new and need help" question here.

Post by metiz » Wed Oct 23, 2019 11:29 pm

JustinG wrote:
Mon Oct 14, 2019 7:23 pm
Hey! I'm new and I need help.

I'm making a Lockwood pulsejet as my high school senior project and I need specific guidance. The actual design of the jet isn't the problem --I plan on using the Lockwood Patent design-- but I need help learning how to assemble it and where and how to buy/make all the parts.

For the actual jet I think I understand what to do for everything except the fuel injector, I've read up on the rosscojector but I'm not sure where I should put it.

Any suggestions?
Sorry for the late reply, place is a graveyard these days

You can go to the scrapyard to find sheet metal (stainless preferably). To make cylindrical parts, either find tubing in the right size or make a layout (inside diameter times pi for width and the length for, well, length.) cut out the parts using a metal sheer or an angle grinder. Either use a sheet roller to get the parts round or clamp a pipe in a vise and hammer your sheet around it. Weld using mig or tig. For mig I find it easiest to "zap" the edge repeatedly and to slightly overlay the beads. If you go in a straight continuous line, you run the risk of blowing through the metal, especially with stainless steel.

For coned tubes, use this program (or any other CAD program will do) https://www.conelayout.com/ just punch in the inside dimensions and it will spit out a layout for you to print and trace.

For bend parts, either make them yourself in sections, 22.5 degrees (or less) each (use cone layout for patterns), or google for car exhaust parts, steel shops, etc. You can also have them made, here for example https://hs-umformtechnik.de/en/stainles ... ipe-bends/

Make sure to flare the intake, very important.

If you use a Rosscojector, place it somewhere close to the intake opening, in the center, pointing straight back. You should be able to start the motor without air if you use a Rosscojector, so you could make a 90 degree bend in the tube and extend it ~75cm so you can hold it in your hand and play with the right distance (make sure your back is in the wind if you do this outside!). When you find a good distance you can fix the injector to the intake.

And finally, don't use a restriction on the gas bottle (no it won't explode)
Quantify the world.

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