Bomarc (stomp) Missile with optional display detail

[mbauer]

Wow, Yogi, you've done some great improvements for strength!

Caught up on some projects and trying to catch up on my reading!

Bomarc is looking good!

Mike Bauer

[Retired_for_now]

Yogi

[rbeach84]

Outstanding! You sound like you're having fun, too!

[Retired_for_now]

Well.... took 'da niece and 'da nephews out to the Eglin Armament Museum. They do have a Bomarc in the boneyard, but - they couldn't work on the thoriated-magnesium alloy parts when it started corroding. Ended up calling in the boys from Wright-Patterson, who proceeded to cut out all those alloy parts, leaving them with bits-o-hulk. I did get a look at their launch rail back in the trees - apparently one of several versions based on the variant pictures I have. Likely most were locally constructed since they are not "aerospace" equipment but heavy iron, fixed site, one-time-use (strategic nuclear SAM, remember) items.
I did get good shots of the missile erector hydraulics - the ram is forward of the pivot and raises it on the pull. Another tweak ...

Yogi

[Miles Linnabery]

Dear Yogi:
Thank you for the Rocket I'm having a great deal of fun. First Question is about what I would call windage in Civil War Artillery Shells. How tight should the tube be to the launcher. I drilled an end cap to the 1/2" PVC Pipe to fit the blow tube of my 15 gal air compresser. so far it flys longer with no cap and just blowing. helped to use 2 small paper clips in nose cone. I made the rocket before I got the tube so the fit is loose 1/8" windage. would less windage help hold air pressure? Now I have to save lunch money to by the rest of the fittings to make the launcher and try other rockets. I'm wondering if a build manderil of pipe raped with two turns of 20# paper would be good?????
Thanks,
Miles

[Retired_for_now]

Miles, glad to be of service. ??pictures??

The tube is not designed to seal tightly - the 1/2in PVC outer diameter is .840 in and the tube diameter built to plans should be .95 inches so a total 1/8 inch gap (.125") is in the ball park. You want a somewhat loose fit to prevent friction with the pipe - I've never found any "glass smooth" PVC. I've made a few simple tube rockets by wrapping them tightly around the launch pipe - using it as a mandrel - and had some failures to launch (which would likely rupture the tube if you're using your compressor).

That said - if you want a better seal to try for max performance I'd take some long, thin strips of card and glue them around the inside of the tail end of the missile tube to close down the diameter (just like making a thick joiner strip except with several layers). Leave just a bit of clearance to avoid friction. Avoids trying to resize the entire model.

Your idea to wrap the launch tube and use that as a mandrel is a great one - I might use two layers of cover stock card vs. the paper. I should probably set up a few building mandrels like that for my workshop/demos.

The Bomarc (and a few other winged shapes I've fiddled with) seems to launch best when launched softly - see long discussions on controllability earlier - so it makes sense that your best flights are coming by just blowing without using the compressor air flow, no big pressure build up. A soft-stomp is giving me the best results also. About 10-15 degrees on the elevation and a soft launch gives me a quick climb to about 20-30 feet and a glide out to about 100 feet (or a nose down spike if I've got too much weight in the nose).

I added three "cereal box" card disks under the replaceable nose and three extra card disks under the pressure tube's front seal to get the balance for the ones I've built. Couple of paper clips sounds similar. If you get it to balance like the picture in post #10 that should get you close (adjust from there based on your build).

Yogi

[Don Boose]

I've been following this thread without comment, John, but with much interest. The stomp rocket idea looks like something to pursue with the grandsons this summer.

Could you remind me where the info on the stomp launcher is to be found?

Don

[Retired_for_now]

Don, the diagrams for building the stomp launcher are part of all of the model files.
In the downloads:
Bomarc (probably the best copy of the stomp launcher diagram included): Aviation downloads
Nike-Zeus: Sci-Fi and Real Space
Basic Stomp Rockets (easiest to build and quick): Toys & Automata
ARES I Stomp Rocket: Sci-Fi & Real Space
Straw Rocket Launcher plans and activities: Toys & Automata.

Should be some (inexpensive) fun - and if they have distance contests the running to retrieve their rockets should burn off some of that summer energy. Have fun!

Yogi

Added - mbauer's Saturn I stomp rocket is also in the Real Space download section, his basic stomp rocket and tutorial in the Toys & Automata, and he has a large selection of stomp rockets in one set at ecardmodels.

[cgutzmer]

Its now available in the shop
ECardmodels.com Shop
Chris

[Retired_for_now]

As Chris said - detailed model is available through ecardmodels. I'll add the launcher to that package as soon as I finish up the tweaks (correct hydraulic geometry, etc.) and some instructions.
Yogi