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Mellow Yellow Clusters

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mccordmw

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Does anyone know how hard it is for CTI Mellow Yellow to ignite? Considering a 3" 3x29 mm H42 MY cluster, but I need to make sure they will all start at the same time. I don't have a lot of experience with the slower burning engines.
 

djs

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No experience with the H42, but I've flown the G33. It's sometimes finicky to light and slow. Also, one time saw it light for a split second, stop burning, sit on the ground for 2-3 seconds, and then relight again.
 

mikec

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I've only flown 38mm Mellow motors but haven't had any difficulty in igniting them, even in airstarts. Note that for CTI motors, you have to get the igniter in close proximity to the BP pellet at the top of the core for reliable ignition.
 

ThirstyBarbarian

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I hope you can get it to work. That should be a nice flight with a long burn.
 

Salvage-1

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I have flown a few of the larger Mellow loads (L265), and i have seen a slight delay between the pop of the starter and the motor coming up to pressure.
You are using smaller diameter, so they should pressurise faster.
The only problem that i see is, if you are starting them both on the ground, and one decides to have a slight (1/4 sec) delay.... your flight will not be that good.
Airstarting... oh yeah..
 

jd2cylman

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No experience with the H42, but I've flown the G33. It's sometimes finicky to light and slow. Also, one time saw it light for a split second, stop burning, sit on the ground for 2-3 seconds, and then relight again.
And THAT wasn't fun... :wink:
 

crossfire

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Maybe not a good motor to cluster?
 

ThirstyBarbarian

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No experience with the H42, but I've flown the G33. It's sometimes finicky to light and slow. Also, one time saw it light for a split second, stop burning, sit on the ground for 2-3 seconds, and then relight again.
When you say "sit on the ground", do you mean sit on the launch pad, or on the actual ground? There's nothing like having a rocket do a 4.4 second burn after taking off in a random, unguided direction...
 

djs

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When you say "sit on the ground", do you mean sit on the launch pad, or on the actual ground? There's nothing like having a rocket do a 4.4 second burn after taking off in a random, unguided direction...
Rocket went up off the rod about 5 feet, landed on the ground. I remember thinking "yup- weird burn there- guess it was a bad motor".. then it re-ignited and had an unplanned encounter with Mr. jd2cylman. It was an Art Applewhite priority stealth odd roc.
 

mccordmw

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I'm thinking I'll skip the MY for clusters. Too much anecdotal evidence of delays in ignition.
 

mccordmw

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Now I might consider 3 inline motors with airstarting a central MY and using faster motors on the outside to give it a kick. Gotta check weights, though. And I'm not sure I can pack that into a 3" mailing tube. I'll check my stock to see if I have any 4" tubes for the booster and then transition to a 3".

I just have so many stinking 3" tubes to use up. I have 16 2' x 3" tubes on hand. :facepalm:

Must...focus...on...L3 for now....

Ooh! Shiny!
 

terryg

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There was a amazing night launch rocket at LDRS 35 with a cluster of CTI Mellow Yellow engines. It was brightly lit with 2000+ leds and the flight was a slow elevator like liftoff that just kept going and going.
 
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