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New 24mm G motors!

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RocketboyG80

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I just checked the Ellis Mountain site and found that they plan to sell 24mm G37 motors soon. I gotta buy one of those when they come out, you'd get some serious altitude with a minimum diameter 24mm rock. They're pretty long though, at 6.875". Does anyone remember the length of RocketVision G55's?
 

Ryan S.

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sweeet. I will have to save that executioner from the F21 and put one of those bad boys in there
 

n3tjm

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Be very careful with Ellis motors... they do not have much lifting power... nice long burns though.... and cheaper than Aerotech.
 

firemanup

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Even without much lifting power i second the executioner idea, it's not a heavy bird... as it's easily lofted by estes d motors.

I know nothing of the ellis mtn motors.. i'm hoping they're single use...? as long as no hardware is involved i'd be willing to risk the old executioner alone up on one of those...
 

n3tjm

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The Ellis motor should have no problem with the Executioner.... I was not referenceing that when I warned about the lifting power.

These motors are disposable. The motor is slow burning and hard to ignite. I seen cases where the delay grain ingnites... and the propellant goes a few seconds afterwards. The 29mm motors have a full diameter delay. I am not sure about their 24mm motors though....
 

Ryan S.

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I dont know I dont think they will have much troulbe lifting a 24mm rocket, if the rocket is made with a 24mm mount I would think a G would have no trouble lifting it but thats just me
 

RocketboyG80

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That is true. I used a G35 motor in my dual deployment Legacy and it had some wobble in flight due to the increased weight from the altimeter bay. Thrust is probably comparable to a AT G33; not very high. Also as Doug said they are very hard to ignite. I used a Magnelite and it failed. I then used a Quickburst Twiggy, and after a considerable delay it chuffed then ignited. Although I do love the sound of those extra long burns.
 

DPatell

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I was actually surprised at the Ellis' lifting power. I flew the 29mm I69 in my 5lb Expediter, no trouble at all lifting it. Good long burn, too. Lit right away.

I had heard they were kinda junky motors, but that changed my opinion on them.
 

solrules

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Originally posted by DPatell
I flew the 29mm I69 in my 5lb Expediter, no trouble at all lifting it.
Well, it should! :)

69N Average Thrust
/ 4.45Newtons->Pounds
=15.5 Pounds

15.5 pounds
/ 3 (yes, 5:1 is recommended, but that is a FAST liftoff! more realistic is 3:1)
=5.16 pounds maximum recommended liftoff
 

wyldbill

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Don't forget when making these calculations that you're using an AVERAGE thrust. It's a good idea to look at the thrust curve to get an idea what sort of thrust you're getting at the beginning of the curve. A progressive burn motor of the same average thrust as a regressive burn motor might not provide adequate speed off the rail where the regressive might. Never hurts to sim it and check your airspeed off the rail.

FWIW,
-bill
 
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