www.pulse-jets.com

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.

I think there is a popular misconception that valveless motors are less gutsy. Not true, BTW. Nothing beats a proper valveless, if your goal is run-forever. And I think I am safe in saying that no mechanical valve can come in at less weight than flappers.

My own efforts made this little motor ...

Well, sure, with a ball valve and a big motor to drive it in a lab. I think the point has usually been "practical use in a flight unit".
That paper is a good read, though, thanks!

In part it seems like a question of balance, matching the exhaust tube and chamber volume to harness the effect. And surface area ...
https://www.youtube.com/watch?v=bDItSUeykrA [/u]
Small ones are interesting too, I wonder just how small you could make one?
https://www.youtube.com/watch?v ...