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Jetex model rockets?

Started by mizzarrogh, April 24, 2023, 11:16:34 AM

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mizzarrogh

There was in the past (like the 1950-60s) as i remember a British made reusable model rocket engine series called "Jetex" which came in many different shapes and size.
One of them was a space rocket, but there was basically anyting one could mount them to, from miniature jetboats to racing cars.

The engine where powered by some red tablets.

Today they seem to be rare collectibles, and i really could not find any replacement fuel for them, so i wonder if anybody here know what to load those engines with today?
I finally managed to get one of the smallest models on a national online auction a few years ago, and have felt excited to try it ever since, but unlike most other toy engines from that era, Jetex fuel is nowhere to be found, except rare, collectible, old stock from the 1960s.

So, Would possibly somebody here be able to help me out how to fire it up again if i ask very kindly?  :)

J. Wilhelm

Ooof! That's long before my time, and I'm old! I don't think I ever saw those on this side of the Atlantic. The ones I knew from the 70s (still very much available today) were Estes brand non reusable solid fuel cartridges. They were made from rolled cardboard and had a tiny ceramic de Laval nozzle at a time I didn't know what a de Laval nozzle was :D I wasn't old enough to play with those until the 1980s.

mizzarrogh

Thank You, i am born in the 70s to be honest,. but i really love old tin toys! I even kind of collect them, at least those i find more interesting. :)

Jetex does rarely show up where i live, i think some toy company did import them, but they where not common here, i bought my last one from Britain (sometime they go for relatively affordable price in Britain if they are in used condition) because i really wanted to study it in person and if possibly make a testrun.  :)

I think i know what You mean by those Estes rocket engines, i have a similar rocket model who use them. (I have the Sagitta and a flying Me 163 toymodel, i have not finished yet, but i look forward to try it!).
(There is a German company who sell similar parts in Europe, i think it is the same type as Estes have in their standard, i did order some ignitors, and firing handles, etc from them a while ago for the model plane)


Unfortunately i don't think they work in the Jetex engines, but thank You anyway!
The Jetex tablets where mounted on a metalmesh inside and connected to a paperfuse.
It is not Beta tablets or anything like that, neither is it gunpowder. But I have not done the tastetest...   ;) (i think they are toxic so i would not recommend that, in case somebody, like me, actually considered it. Ha ha)




mizzarrogh

Off Topic.
I don't know if they are called "De Laval" nossle in the US, many things hawe different names in different countries, like the Xray, Tungsten, etc.  :)

In sweden De Laval is assiciated with farmers milkingmacines, separators, etc. They did a massive commercial for the new typ of pulsating vacuum milking macines here in the 1890s and early 1900, the milking macines even came with a lightbulb armature to set outside the barn so oters could see that one had it installed just by walking by on the road.  :)
In Sweden De Laval and Nobel company where the late 1800s SpaceX and blue Origin.  :)

J. Wilhelm

Quote from: mizzarrogh on April 25, 2023, 11:50:36 AM
Off Topic.
I don't know if they are called "De Laval" nossle in the US, many things hawe different names in different countries, like the Xray, Tungsten, etc.  :)

In sweden De Laval is assiciated with farmers milkingmacines, separators, etc. They did a massive commercial for the new typ of pulsating vacuum milking macines here in the 1890s and early 1900, the milking macines even came with a lightbulb armature to set outside the barn so oters could see that one had it installed just by walking by on the road.  :)
In Sweden De Laval and Nobel company where the late 1800s SpaceX and blue Origin.  :)

I think this Wikipedia article explains it's usage.  At college we don't call it that. We simply refer to it as a "Converging-Diverging Nozzle.". DeLaval is old terminology.

https://en.m.wikipedia.org/wiki/De_Laval_nozzle

mizzarrogh

Thank You! It seem after all that i still remember something correct.  :)

The reason the ready made rocket motors (or other blackpowder fired engines i know about, but possibly a modified witch whistle would do if one shorten down the plastic shell, actually, now when You did mention it! ) does not work in the Jetex is because it already has a built in ceramic nozzle and the case is very short.

(i think it came a bit later, like the mid 1900 or so, but) The Jetex is very stempunk as it is in my opinion. I considering making a rocket for one of them, the other one has a little rudder attached to it, so it is probably made for a miniature racingboat.

But, Yes, if there is no longer any suitable fuel available for them, i probably have to go for regular gunpowder motors.  :)