Search found 1575 matches

by metiz
Thu Feb 29, 2024 3:24 pm
Forum: Valveless pulsejet forum
Topic: Please put your "I am new and need help" question here.
Replies: 404
Views: 1940198

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

The ID sounds exactly right. The outside diameter is a bit sus, but it doesn't really matter, only inside diameter matters. If you want to be sure, print the pipe and measure. you could also post an autocad file of the flat pattern here, then I'll check it. If you do, note which part it is.
by metiz
Wed Feb 28, 2024 10:24 pm
Forum: Valveless pulsejet forum
Topic: Please put your "I am new and need help" question here.
Replies: 404
Views: 1940198

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

I don't recommend overlapping edges, it impedes air flow. I use Sketchup with a lot of "CAD-CAM" stuff because it's very flexible. I use a small plugin "unfold" that allows you to unfold faces. Sketchup has a fairly low resolution so I just click on every face of the cone, or whatever else kind of m...
by metiz
Wed Feb 28, 2024 6:58 pm
Forum: Valveless pulsejet forum
Topic: Please put your "I am new and need help" question here.
Replies: 404
Views: 1940198

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

For layouts, I use Sketchup. I "unfold" the models myself so I have to compensate for material thickness. I don't have experience with sheet metal in solidworks, but if the program compensates for sheet metal thickness, you don't need to change anything. Can you print a pattern for a straight pipe o...
by metiz
Wed Feb 28, 2024 10:55 am
Forum: Valveless pulsejet forum
Topic: Please put your "I am new and need help" question here.
Replies: 404
Views: 1940198

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

"All the dims I have been dealing with are internal dims, are you saying I should add additional width on to the dimension of the flat pattern, based off a part modelled on the ID? I've never had to work sheet metal to this accuracy before." No, increase the diameter of your pipes and cones by 1.8mm...
by metiz
Wed Feb 28, 2024 12:16 am
Forum: Valveless pulsejet forum
Topic: Please put your "I am new and need help" question here.
Replies: 404
Views: 1940198

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

That's a great deal, go for it. Don't forget you have to compensate for the sheet thickness in your flat patterns: all dimensions in these drawings are internal so if the sheets are cut with the dimensions as stated, your engines' diameters will be off by 0.9x2=1.8mm. Also have the intakes cut sligh...
by metiz
Sun Feb 25, 2024 9:32 pm
Forum: Valveless pulsejet forum
Topic: Please put your "I am new and need help" question here.
Replies: 404
Views: 1940198

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

I use 0.8mm wire. The paper you linked discusses a valved engine. Valved engines do not have a protruding intake or a coned exhaust so effective length=engine length (maybe not including the small length at the front of the engine taken up by the valve) and mean diameter is what it sounds like. It's...
by metiz
Sat Feb 24, 2024 10:54 pm
Forum: Valveless pulsejet forum
Topic: Please put your "I am new and need help" question here.
Replies: 404
Views: 1940198

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

I think your best bet is to get some scrap sheet steel from the scrapyard. It's where I get all my stainless. You can roll of hammer it into the pipes you need. 304 works fine for pulse-jets and is much cheaper too. Go for the 0.9mm stuff as it is easier to work with (and cheaper). In my experience,...
by metiz
Thu Feb 22, 2024 11:42 pm
Forum: Valveless pulsejet forum
Topic: Please put your "I am new and need help" question here.
Replies: 404
Views: 1940198

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

I can answer questions 3 to 5, to a degree. I don't really understand what you are getting at with the first 2. 3: You can get 3" pipe from exhaust manufacturers. Although having a smooth 180 degree bend is ideal, you can definitely get away with cutting straight pipe up into six 30 degree segments ...
by metiz
Wed Feb 07, 2024 6:01 pm
Forum: Tools and Construction
Topic: Odds and ends
Replies: 1850
Views: 812611

Re: Odds and ends

Mike Everman wrote:
Wed Feb 07, 2024 1:38 am
Hmm, I have some hollow 1” bearing balls…
That comes with age :D
by metiz
Wed Nov 15, 2023 2:45 pm
Forum: Valveless pulsejet forum
Topic: More free plans: 40 pound Chinese
Replies: 192
Views: 820503

Re: More free plans: 40 pound Chinese

Good job on the flares. It looks like you are still not getting nearly enough fuel to your engine. Are you using a full, or fairly full propane tank? What's the temperature over there? If it's freezing, you might not be able to start the engine even with a full propane tank. Something I would not ad...
by metiz
Fri Nov 10, 2023 8:11 pm
Forum: Valveless pulsejet forum
Topic: More free plans: 40 pound Chinese
Replies: 192
Views: 820503

Re: More free plans: 40 pound Chinese

Hi Redstone, welcome to the forum I have some notes: 1: Lose the regulator. You will never get this engine to run without full flow from your propane tank 2: Looks like you MIG welded your engine. Try spot-welding the slits you have at the end of your intakes closed and then file the welds smooth on...
by metiz
Fri Oct 06, 2023 6:27 pm
Forum: Valveless pulsejet forum
Topic: Mike's Build Log
Replies: 441
Views: 323566

Re: Mike's Build Log

About time someone posted something here again! See what I did there?....I'll let myself out. Nice clock Mike!
by metiz
Fri Oct 06, 2023 6:26 pm
Forum: Off topic forum
Topic: youtube
Replies: 1510
Views: 537165

Re: youtube

I like how they answered their own question in the video title. No clickbait.
by metiz
Sat Mar 25, 2023 12:29 pm
Forum: Valveless pulsejet forum
Topic: Mike's Build Log
Replies: 441
Views: 323566

Re: Mike's Build Log

Hi Mike,

Have you ever gotten around to play with these engines some more?