www.pulse-jets.com

I've seen the 2.5 pressure ratio before. Thanks for that.
Valvers are certainly less drag and shorter, but I wouldn't place valveless in the "only a noisemaker" category.
I have been won over by valvers a great deal, though. I've watched as valve life went from low to almost indefinite with ...

Ha, makes me think of the butterfly effect, only instantly gratifying. Thanks, Mark.

Very nice work! It makes me want to model my pocket jet valveless in it and see what it says.

Sorry the site was down. It was being attacked and the forum needed upgrading. I know at least one person noticed!

Nice, love those lil things. I’m about to make my Levin go servo-indexable.

boy that guy really does a lot of engine experiments of all types!

You've inspired me, Simon!
Cross-slide encoder works great. Happy little green light.

IMG_6377.JPG

And when I took this photo of the DRO, I realized you can hardly see it in the sea of bric-a-brac! I literally just noticed you can switch from mm to inches with a button. I've used it to test ...

Optical tape. Good to better than 3um per meter. Renishaw RGH41. I’m doing simple extrusion ledges to stick it under. I’m not set up for flood coolant, as I never do any real hogging. Tomorrow I find out if I can drill and tap into the edge of the cross-slide bed. Seems kinda hard.

Ha! making your own bevel gears, go you indeed!
Do you think it knows it is making it's own replacement? shhh

Fun!
I just mounted a Renishaw DRO next to my Smithy, and now to put tape scale and 1um read-heads. I've been doing various setups with plunge gauges to do fine work, and I'm sick of it ...

Cool, let's see it! I've got a Smithy and a Levin 8mm watchmaker's lathe. Love them both.

Very nice, Alex!!!

Interesting, Alex, Thanks. some of us will definitely check this out!

Nice, Wayne. Welcome.
Ever read Jerry Pournelle and Larry Niven's Footfall?

Ha ha!
Time so flies, dunt it?

The main issue with this is weight. You can make the outer jacket thin, but the inner one must be thicker or the pressure between will crush it with external pressure. I think you are better off injecting water in the right spot for greater thrust.