Making a pararell staged rocket?
 

I hope this the right place to post this. How can you make a parallel staged rocket from an existing kit?I was thinking of building my Quest Force 5 as one.

Personally I don't have a Quest Force five. So someone can chime in please with actual body tube sizes ect.

Is your force five built, or in the bag? I'm wondering if built you can get the Center of Gravity measurement.

Looks like a good candidate for a parallel stager, ( I love parallel stages!)
If your just adding motors to the stock rocket, that should not be too hard. If your planning drop off boosters then that's another story.

Basic add motors version: (edit,for a parrellel cluster)

First step: Get centering rings, motor tube, and motor stop rings that fit the side pod body tubes.

Second step: dry fit everything if possible. Put the side motors in (going to use booster-0 motors?) and the main, and all the recovery goodies. Then with it loaded you can adjust your center of gravity by adding nose weight. It may take quite a bit of nose weight.

Then weigh the finished rocket and choose a larger chute.

Maybe someone has the CG info of one that is already in service?

Lets see some build photos as this goes along, sounds like a nice project!


Did I say I love parallel stagers?! See below. 19 motors 6 parallel Second stages. (I built part of this) LDRS28 Sooon to fly again this fall!


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Thanks.How do you mount the boosters and how do eject off the main body?

I looked around for some photos of the Force-5 and attached them below. Borrowed 'em from the Quest website. Hope that's okie dokie, but it's all I could find... besides looks like a cool kit!

Again I do not have one, soooo... maybe someone who works at Quest could chime in give some advise on that model also (hint hint). ;)

What I would do (remember kids I am not a role model)

Looks like the side mounted tubes are built “stock” with some cool nozels that are canted. I would not cant the added parallel stage motors... but you could if you where crafty enough I'm sure!

Some one with the right info can post what the side tube size is then make up two motor mounts to slip in the side booster tubes.
In these tubes I would use only Booster Motors. These have NO ejection charge. They provide the boost and that's it. Look for motors with a ZERO ( -0 ) designation for the ejection delay.

Ejection is handled by the Center or main motor that will have an ejection charge and completes a typical model rocket recovery flight plan.

Food for thought. If all works well, your rocket will go higher than a standard flight and will be traveling further in it's coast phase. So think about a longer delay for the center motor than you would in “standard” single motor mode.

Maybe one of the Rocksim gurus here can sim it for you. That would be a huge help as I am not a Rocksim user.

Hope this helps.


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Parallel Stages
 

I've enclosed a few photos. First is of me and my only pre-launch of the force 5. Lost in trees and reg single motor. Second is of a "parallel stage" rocket I call "Spaceman spiff and the rocket of death." (3 bull pup 12 D's glued together) In this photo going out of control cause pulled "launch rod" right out of launcher! If u do a search on You Tube for "Naram51 First", u will see a rare video of spiff coming apart.
So heres the story. With my rocket, all 3 motors were 18mm. Outside pods used B6-0s and main used B6-2 for first flight. Outside pods had holes cut in sides for exhaust gases to escape. Main had a payload tube to carry an "action figure," Spiff, for added balast or weight.
You may have to do the same with the force five , only use clay for balast. Those outside pods r 13mm, so u may have to eliminate "nozzles" for launch and just have them on for "decoration," or not glued in place.
Spiff was my first parallel staging and worked great on very first flight. However, as u see in photo and video, has its drawbacks. After extensive repairs, flew again @ night @ Naram 51, to an "awestruck" audience, only to have "lights" kicked out after a spectacular launch!
I'm going to say, just make darn sure u use "Epoxy" on the side tubes w/holes cut in each one. Also, a moderate amount of additional clay in nose and a "spin test" for stability to check flight. Good Luck and hope my experience helps. ;)

Garmtn, first of all, gotta say I love the reference to Calvin & Hobbes! Second, per the quote above, I'm curious as to why the outside pods needed exhaust management? Wait, nevermind- the burn-through...okay, well, disregard this part. I'm not deleting it because I really do like the Spaceman Spiff name. Also, looks like a double-whammy in the picture on the right- not only is the launch rod along for the ride, but it appears that maybe the right booster didn't ignite? May have contributed to grabbing the rod? I've only flown clusters for this very reason- am nervous about delayed ignition of an outside engine affecting trajectory; that said, do you have any tips for increasing the reliability of simultaneous ignition? 12V Battery with non-standard igniters, or am I just being too cautious? Nice looking build!

:chuckle: That's what makes clusters and parrallel staging so much FUN! There's a potential for more things to go wrong. When it goes wrong it's kind of cool.

But when all goes right.... it's awesome!

Some tips real quick.

-12volt car jumper pack or Cluster box relay type ignition.

-Long igniter leads, and or clips atached to enough wire that the whole assembly can travel up a bit if it all does not instantly ignite. That gives everything a bit mor time to get lit.
Somewere I have a photo of a good setup where I used a dowel to hold up the wires for added travel (as in boost glider style.) Some one must have a photo like that they could post here?

-dip your own style igniters.

reference reading: http://www.bpasa.com/Rocketflite.htm



.mmmmm makeing me day dream of clusters now.

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I was planning to do a Space Shuttle type parallel boost where the boosters fly off when the motors cut out.Is that possible?

MPi,
Amibitious, but doable (I think!). There are some great tips in the Stine's seminal compendium of all things ModRoc, The Handbook of Model Rocketry. In short, a hook is mounted near the top of the booster pod(s), which engage a slot cut into the sustainer airframe. A spacer (piece of balsa) maintains the distance at the bottom of the booster. The hook faces forward, kinda like...well, there's no key on my keyboard that looks similar. I guess a little like this ~ turned 90 deg; when the booster thrust engages, it forces the hook to lift the sustainer. When booster burnout occurs, the drag now minus the thrust is enough force to disengage the booster. Ambiguous description, I know...if you don't have it, go by the book...it's awesome and has great pictures/drawings for tricky things like this. (yes, there are some things the internet just ain't cut out for)

Good luck, and post pictures if you try this (something I've wanted to do since my Estes Shuttle lawndarted 15 years ago)!

I still have the old CMR Marcus strap-on boosters that worked very well. These used booster engines and had an attachment system that used a bottom hook that fit over the body tube at the bottom of the rocket and another that fit into a slit cut into the body tube further up. After the booster engines quit thrusting, the wind presure pulled them away and also pulled the upper tube off the coupler that deployed the streamer. You had to use motors with shorter thrust times that the center engine. I used them in groups of 2, 3 or 4.



I think I gave Scott the kit instructions, but I do not see them in the CMR plans.

Joe W