Hello All,

The Czech Republic-made Rapier jet motors (see: http://www.jetex.org/motors/motors-rapier.html and http://www.rapier.cz/ ), which were a single-use, model rocket motor-like substitute for the Jetex motors, have apparently been discontinued (see: http://www.jetex.org/scripts/yabb2/...um=1283109111/0 ) due to the legal status of the production facility. Also:

While the Rapier motors (here's a YORF thread that includes a photograph of some: http://www.oldrocketforum.com/showt...03&page=1&pp=10 ) were not legally model rocket motors, they were generally similar, the main differences being the lower thrust and longer burn times of the Rapier motors. Perhaps an "anemic" sugar propellant formulation with, say, an excess of fuel and/or with burning rate reducers would yield Rapier-type thrust/time characteristics. Although such units would not be model rocket motors, I see no reason why a motor manufacturer (U.S. Rockets or another composite motor maker, maybe?) couldn't produce Rapier replacement motors as a "side venture" to create an additional stream of income.

__________________
Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see:
http://www.lulu.com/content/paperba...an-form/8075185
http://www.lulu.com/product/cd/what...of-2%29/6122050
http://www.lulu.com/product/cd/what...of-2%29/6126511
All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com.
NAR #54895 SR

I imagine for the amount of motors sold would be a minimal compared to rocket motors. Not worthwhile. Rapier powered aircraft seem to more popular in Europe than here in the States.
IMO

__________________
If it flies, I can crash it!

People don't ask for what they aren't aware of. Jetex is a vague memory to most aeromodelers, and many here probably never knew about the Rapier motors. Another possibility (given the low thrust/long burn characteristics of these motors) is a readily-reproducible, "roll your own" design, something which--like the Five Cent Sugar Rockets--could be made by the user in quantity from readily-available materials.

__________________
Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see:
http://www.lulu.com/content/paperba...an-form/8075185
http://www.lulu.com/product/cd/what...of-2%29/6122050
http://www.lulu.com/product/cd/what...of-2%29/6126511
All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com.
NAR #54895 SR

I've seen several amazing scale jet free flight models fly with old Jetex. Very smoky and cool. I bet they would have a following if something like them were readily available.

__________________
Derek McGuckin
Tri-Cities Rocketeers
www.tricitiesrocketeers.org

I cannot help but wonder how these would fly with the new AeroTech C3(po) and (r2)D2 motors...


Bill

__________________
It is well past time to Drill, Baby, Drill!

If your June, July, August and September was like this, you might just hate summer too...

Please unload your question before you ask it unless you have a concealed harry permit.

: countdown begin cr dup . 1- ?dup 0= until cr ." Launch!" cr ;

Give a man a rocket and he will fly for a day; teach him to build and he will spend the rest of his days sanding...

I think you're onto something here! In Europe, there are competition black powder model rocket motors with average thrusts of just 1 newton (A1, C1, etc.), which are typically used as upper stages of scale altitude or duration models. Motors like those would be well-matched to Rapier/Jetex Free Flight (and perhaps even micro R/C) jet airplane models. I see two possibilities here, which could each have their market niches:

[1] Single-use black powder jet motors similar to the low-thrust European model rocket motors. They might use a slightly "souped-up" version of the delay charge black powder formulation used in model rocket motors, for low thrust/long burning time and to produce plenty of smoke, which Rapier/Jetex flyers like (for scale realism as well as for tracking).

[2] Reloadable composite (or perhaps black powder) jet motors that would be mechanically similar to reloadable model and HPR rocket motors; the "Smoky Sam" composite propellant, in a cigarette-burning (end-burning) grain design in a narrow motor case, might be ideal. If necessary, burning rate reducers could be added to the propellant. These reloadable jet motors, like the RMS motors, would cater to frequent flyers and contest flyers, while the single-use jet motors would be preferred by casual sport flyers. Also, the reloadable jet motors would be cheaper (in higher-impulse versions for larger planes) than single-use jet motors of higher impulse, quickly resulting in significant savings after a few flights.

__________________
Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see:
http://www.lulu.com/content/paperba...an-form/8075185
http://www.lulu.com/product/cd/what...of-2%29/6122050
http://www.lulu.com/product/cd/what...of-2%29/6126511
All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com.
NAR #54895 SR