Summer Build Contest 2017 "Little Davey's Launch Pad."

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Oddroc scum. Mindsimmer.
TRF Supporter
Jan 23, 2009
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Littleton Colorado
Four free sliding motor mounts glued together over a huge launch lug, smashing into a JB Welded cap which in turn launches a tractor motored rocket that looks like a launch pad. Once the thrust backs off the mount can again slide back as needed (or not) for deployment ejection. Once the four chutes are out the mounts can slide back up and smash yet again into the cap stop.

Yes Mr. RSO, I know it can work. Yes it looks just like a launch pad sitting out there, but there is a sturdy 3/8" launch rod going down the center that is firmly planted in the ground. Yes it looks like little Davey is going to launch yet another seemingly dangerous, clustered and fin less rocket, but in reality it will all become one big tractor motored rocket. Yes, the motors start out near the bottom of the rocket - where they should be - and then slide up and hit what looks like a rod cap carelessly left on the rod, launching a funny looking, tractor motored, flying launch pad abomination, but what fun could be had! Really, when those motors slide up and hit the heavy cap, the CG is super good! Even with the mount sliding back after trust and propellant burn out, it will still have a lot of nose weight an momentum, and just look as those big launch pad fins at the back of the rocket, a picture of stability. Yes, the launch lug and nose weight nut/washer are metal, but I need the metal to make this one work, just like the high power guys need the aluminum tips and fin cans with the big motors. This one is just four wimpy D12-5's. Yes it looks like naughty little Davey is launching an obviously unstable clustered rocket with the safety cap left on, which in turn takes the entire pad into the sky, but that is the whole point of oddroc fun.

Mindsim, upgraded version, plan print out:
Launch pad plans.jpg
The plan has been reviewed by real United Launch Alliance rocket scientist.

Parts laid out on couch:
LP 7.jpg
Notice Estes "yellow 24mm reinforcement tubes" left over from previous builds. All scrap, left over and hardware store sourced parts. Very low budget.
Build pictures from this weekend.

Motor blocks and yellow reinforcement tubes glued in. AT igniter tubes use for external reinforcement. Nose cones reinforced with CA. 1/4" balsa fins papered. Washer and nut JB welded on. Decided to smear some yellow glue on the rest of the exposed tubing. Poor Boy Phenolic! Not classy Blue Tube, rather, nasty yellow tube. But real strong and light. Used some plastic strakes to fill in some of the gaps.

Time for paint!

LP 6.jpg

LP 3.jpg

LP 5.jpg

LP 4.jpg

LP 2.jpg

LP 1.jpg
I'm watching this build with interest, and also plan on entering the SBC.

I just wanted to say, please, if you haven't already considered it, be sure to strongly secure the 'cap' of the launch rod. Looking the at pictures is fun and insightful, but only goes so far. I can't tell from your sketch or the parts you laid out, but from the general arrangement, the moving part of your rocket (the 'booster?') wouldn't be stable if free-flying. There's going to be a pretty large impact force when the booster hits the top of that rod. If there was a failure, either of the rod 'cap' or of the booster's themselves, I'd hate to see your booster (or parts of it) go flying off, unstable, potentially causing damage or injury. It sounds like the launch would be at a pad fairly well removed from the flight line and that may provide some protection. On the other hand, if the booster sheds the 'pad' weight, those engines could go quite far. Just something to think on, if you haven't already. If it were me, I'd consider some kind of softener to reduce the impact/impulse at the top of the rod, rather than just a hard stop.
The "cap" is a steel washer and nut JB Welded to the aluminum tube. It is extremely secure. The booster is also extremely robust, everything being reinforced short of glassing. The impacting nose cones are balsa with a coat of CA, so they are a bit "soft". The booster pod is meant to look like an unstable cluster rocket, hence the "Naughty Little Davy" stuff. For full effect it has to be a staged, heads up launch, only in front of Top Men at a secret launch site. The planned launch lingo will be quite unique if allowed.

I will get some more photos as it is in paint now.
Sounds like you've thought it through. I figured as much. :cyclops:

I'm looking forward to paint on this one. Lots of opportunity for detail.
Sounds like you've thought it through. I figured as much. :cyclops:

I'm looking forward to paint on this one. Lots of opportunity for detail.

Only as far as mindsim can take me! Going to do a Pershing 1A like scheme on the booster pod. All kinds of applications for this type of rocket from Slide Rules to oil rig towers to Wonkavators.
View attachment Tractor Motor concepts.pdf
That's different for sure..just remember..and I know you thought it all thru...but I still I have to say this..."Safety First"

Thanks for entering the MODSBO Contest.
Lookin' good.

Thanks. Maybe you could build something too!:) Possible ideas: Cant the motors on basically the same platform and pull up branches to make a tractor motored Christmas Tree rocket? Haul up some telescoping ring fins to make a layer cake design for the wife's birthday. Haul up a flag or banner (canted motors.) Tape some Barbie dolls on to the mount - JET PACK BARBIES! Make an atom smasher or an interior profile of Little Boy where the "gun" method worked the first time with out testing! An erupting volcano with a big cone fin - canted motors - pyroclastic flow! Life at conception - where the sperm crashes up into the egg, sure to get bonus points from both your Priest and Biology Teacher! Pop the Zit - OK, now I am getting into trouble, but it could work if you think about it!
Estesland it was. After review by Top Men I once again found myself enjoying the quiet solace of the away pad while hooking up the four Mighty D motors with the spider like clip whip.

Photos on pad:
DLP 2.jpgDLP 3.jpgDLP 18.jpg

Photos of flight:
DLP 4.jpgDLP 5.jpgDLP 6.jpgDLP 7.jpgDLP 1.jpg

All motors lit, flew up nice and straight like any good tractor motored rocket will. Then POP POP POP POP, little bits flew off. One chute of four deployed. One chute ripped off. One chute burned the shroud lines off. One chute just never caught enough air to deploy.

Thanks to Deanna Mann for the flight photos!
Post flight pictures and repairs. Two of the motors blew out the back. One hit directly on the fin knocking out a chuck of balsa. Flame action peeled back the label paper. Dents in the nose cones show the power of impact and ejection. Never underestimate the POWER of the MIGHTY D motor! Got a kink in the launch lug on landing with only 1.25 chutes. Jammed the 3/8" launch rod through and pounded out the damage. It will hang up a bit now on the 3/8" rod, so will have to go with a 1/4" rod for the next launch. So much for metal parts! Glued in a piece of scrap balsa on the fin. Super glued the paper back on. Cleaned up the soot. Gave it a quick Sharpie pen touch up paint job and ready to go again when I can get some more Q2G2s.

DLP 10.jpg

DLP 11.jpg

DLP 12.jpg

DLP 13.jpg

DLP 14.jpg

DLP 15.jpg

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DLP 17.jpg
Woohoo! A stable flight and an opportunity to rebuild. Sounds 100% successful to me!
I have to say this thing is wacko even by oddroc standards. I love it. :)

Get any video? I'd love to see the initial stage of the four-motor pod thing charging up the rod and hitting the stop at the end.
The damage isn't even as bad as I would have expected considering you only had one good chute and a nose down trajectory. And I'm with Neil, I want to see video!
I have to say this thing is wacko even by oddroc standards. I love it. :)

Get any video? I'd love to see the initial stage of the four-motor pod thing charging up the rod and hitting the stop at the end.

Thanks. Could not get the Fancy Phone to work at the last second before the launch, so no video and I actually got to watch it. In reality it is so fast it looks like a smooth launch of the power pod rockets. The noise and smoke of the motors lift the back end of the pad right off the rod, straight, fast and stable. Deanna did catch the moment of impact in her first launch photo above.

Three canted motors on a tripod pad would work well. Less burn and not a substantial decrease in performance.

The whole sliding motor thing is kind of silly and wacko. Maybe a next step would be to make an electrical connection and set off a light or sound effect.