CONTRAIL HYBRID CLUSTER

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legranddudu

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Yes it flies, very well indeed... 2x J /36" casing, Medium nozzle / 1/4 injector and Black Gold reload

Rocket 5.5" diameter /8.2ft long and approx 30 pounds, altitude guessed approx 1800ft, need to read the altimeter these days...

enjoy... next step will be 2x K and 3x J..up to max 3x K

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Fotos & rights with Andreas Hader, thx for sharing with us!
 
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Génial; Denis you make me talk about my idea about hybrid cluster ; If we can build an hybrid with a valve to control the flow of the Nitrous, ( and it’s not that hard ) we can do 2 things ;
1- Make the motors throttle until we sure they are all ignite
2- Control the stability of the flight; if the rocket go on one side we can lower the trust on the other sides ( I'm talking about 3 clusters ) , it should make it return on a more stable vertical climb
 
Wow, that is awesome!! I love the different length exhaust plumes. I bet the sound was incredible!
 
Here the rocket (pictures from the winter launch where we could not start but absolutely identical setup):

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Here some other pics from SAME start and same rocket, looks really different... I suppose the fotografer (Thomas "Schmidi" Schmid/ all rights to him, thx for sharing with us!) had a better position at 90° from the motor axis.. looks really great I think...
This is my first Contrail hybrid cluster and certainly not the last one. It was just so much straight forward and easy...

cluster 1.jpgcluster 3.jpgcluster 10.jpgcluster 20.jpgdetail 5.jpgdetail 15.jpgdetail 20.jpg
 
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Yes, several times. I know of twice with AeroTech hybrids by Bruce Lee, and someone has done it with HyperTEK

Here's another oldie hybrid cluster...4 RATT K240s! I remember always gawking at this back in the day.
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Hey Legranddudu, is there a video?
 
Hey Denis,

Very nice!

Did you do anything special as far as insuring the fill lines both "melted" off in case of a single motor light situation?

I can't believe how similar my motor mount setup is to yours for my cluster project. Great minds think alike, I guess.. ;)
Going to do a 3 motor J sparky and then a HyperTEK K240 3 cluster.

Congrats on a sweet flight. I'd also like to see video if any is available!

Jason
 
Jason,

I would add an additional pyrodex grain outside, connected with the other ignitors inside and tape all fill lines together with it. So far I did not see any videos of the launch, just pictures. We were so busy we even forgot to switch on the GoPro... Hopefully you will document better your coming hybrid cluster. You said 3x J, also Hypertek?

Denis


Hey Denis,

Very nice!

Did you do anything special as far as insuring the fill lines both "melted" off in case of a single motor light situation?

...
Going to do a 3 motor J sparky and then a HyperTEK K240 3 cluster.

Congrats on a sweet flight. I'd also like to see video if any is available!

Jason
 
I was thinking the three fill hoses taped together as well. I worry about the igniter with the pyrodex pellets on the lines outside but a couple or three pellets that the flame can touch and light after motor igniting will make sure all lines are severed.

I hear you on the no video or "extra" stuff besides the flight. I'm no better. I want to make sure the rocket and motor do its thing and don't worry so much about the pictures. I will have to make sure I talk a couple of guys into taking pictures and video. I won't have this rocket ready to fly until next spring. Too much to finish(I think) for an attempt this fall. First flight will be on 3 Contrail J-416 Sparky motors. If all goes well and testing of lighting 3 HyperTEK K-240 motors works out I'll do the cluster of them at a later date. More unsure of this combination and may even do some actual motor burns statically to make double damn sure I have it sorted out. :) Plus it may be a good excuse to make a thrust test stand. ;)

Jason


Jason,

I would add an additional pyrodex grain outside, connected with the other ignitors inside and tape all fill lines together with it. So far I did not see any videos of the launch, just pictures. We were so busy we even forgot to switch on the GoPro... Hopefully you will document better your coming hybrid cluster. You said 3x J, also Hypertek?

Denis
 
Jason,

I think the contrail Sparky II reloads are an excellent choice as they ignite nearly in a fraction of a second. I used the black Gold ones with success in this first cluster flight but next one will be sparky also. But make sure you have watered the ground below before. I very dry environnment I bet you put the soil on fire with 3 sparkys...


.... First flight will be on 3 Contrail J-416 Sparky motors....
Jason
 
Génial; Denis you make me talk about my idea about hybrid cluster ; If we can build an hybrid with a valve to control the flow of the Nitrous, ( and it’s not that hard ) we can do 2 things ;
1- Make the motors throttle until we sure they are all ignite
2- Control the stability of the flight; if the rocket go on one side we can lower the trust on the other sides ( I'm talking about 3 clusters ) , it should make it return on a more stable vertical climb

Checkout https://rocketmoonlighting.blogspot.com/

StanO
 
Yes, several times. I know of twice with AeroTech hybrids by Bruce Lee, and someone has done it with HyperTEK

Rich Baker (Hybrid33) has done AeroTech triple clusters several times. He has also flown a cluster with all three motors on a single tank!
But AeroTech is easy as no GSE is needed. :wink:
 
indeed very interesting... can describe/picture your setup and electronics?

thx
The rocket is a scratch built. The booster contained a Contrail J642 and the sustainer had a Contrail H141.
the normal Contrail vent fitting was replace with check-valve and sustainer fill tube was connected to the check-valve. Both motors were filled on the pad. For electronics there was an ARTS in the booster which had it's second channel set to fire the sustainer at motor burnout. The ARTS also was used to deploy the booster chute at apogee. The sustainer had a Missile Works RCC2, in a normal dual deploy config.

A short, not very good video is at [video=youtube_share;1gJADyipepI]https://youtu.be/1gJADyipepI[/video]


Pics
DosNitrous.jpgCoupling.jpg
 
Bob this is...GREAT !!!

I talked to Thomas @ contrail the other day and he mentioned your build. Just awesome idea and obviously proof of concept... Now just imagine a 75mm contrail booster and a 54mm on the top... I need to try this next season. Can you please post details of your check valve construction. The principle is really clear but the details are extremly interesting..

Thx

Denis
 
Bob this is...GREAT !!!

I talked to Thomas @ contrail the other day and he mentioned your build. Just awesome idea and obviously proof of concept... Now just imagine a 75mm contrail booster and a 54mm on the top... I need to try this next season. Can you please post details of your check valve construction. The principle is really clear but the details are extremly interesting..

Actually the plumbing was the easy part. The check valve / presta-loc fitting combo replaces the restricted vent fitting in the forward closure (see pic). The sustainer fill attaches to that. During the fill process NO2 flows through the check valve and fills the sustainer. The sustainer motor is vented in the normal Contrail fashion. There is just the one vent. When liquid is venting from the sustainer then you know both motors are full. The check valve came from https://www.mcmaster.com/#standard-check-valves/=o37w27

The hard part is the routing of the fill line to the sustainer so that it does not interfere with the deployment of the Booster chute. I spent a lot of time thinking of a configuration that would route the fill through the nose of the booster. The light-bulb moment came when I realized that I could just route the fill line externally and bypass the nose of the booster completely. So in the final configuration the fill tube exits the BT just above the motor and is external all the way to the sustainer motor. To make the final assembly easier, there is a break in the fill line, this way I can keep the two stages seperate untill they are filnally loaded on the pad. At the break there is a simple presta-loc to presta-loc coupler.

Using the current multi-piece 75mm Contrail would be more difficult because it vents from the bottom. I think it would work, but it would be a more complicate setup. The mono tube 75mm would probably work the same as the 54/38's but I don't believe that they have been release yet :(

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One year later...

Same rocket, same event, same location.. I bring it to the next level... now K impulse, hybrid 48 inches contrail motors..... but 3 x :eyepop:

Cross fingers for me please..this "thing" is going to make his maiden journey on coming saturday... pics & vids will follow...

Denis

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Here some details about the internal motor geometry, from both sides, the empty rocket and the mounted engine container...

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