Nike Smoke

[blackbrandt]

I am not very experienced with MPR, but I have recently built a 4 inch nike-smoke, but I am not usre how much BP i will need. I am using Piston ejection, any tips would be appreciated.

[crossfire]

If your useing a AT or CTI reload the amount that comes with reload kit is plenty. Yesterday I flew a Mad Cow Rocketry 4" kit. And just went with the BP that the 3 grain 38mm reload kit had. Most of the time there's no reason to add extra powder. With the piston that will even help more with getting the chute out.
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[blackbrandt]

I am using a cluster of an AT E-18, 2 D12' Estes, and 2 Estes C-6's. I am only using the ejection from the E-18. I end up having about 0.8 grams of BP. Is that enough

[jpummil]

I am using a cluster of an AT E-18, 2 D12' Estes, and 2 Estes C-6's. I am only using the ejection from the E-18. I end up having about 0.8 grams of BP. Is that enough

?!?!?

Mixing BP and AP will complicate things as BP "lights" before AP does. This is a VERY unusual mixture of motors...let alone for trying to put a 4" rocket up.

Have you done any clustering before?

[blackbrandt]

Well, I am going to use a comination of a First Fire and flash in the pan...how would you do it?

[jpummil]

I have a phobia against mixing AP and BP in a cluster

You didn't give us a LOT of specs to go on, but I surmise that if this is reasonably to scale for a Nike Smoke, you'll be seriously lacking in thrust for a safe launch.

To add to that, if the BP's DO light earlier than the "E" (and it's likely that they will...at least some of them...), then you may get a situation where the rocket barely clears the rod and angles over about the time the AP fires causing a very unsafe situation to anyone nearby.

An "E" and 2 "D"'s is approximately an "F" (avoiding the 2 "C"'s for now...). Looking at an "F" in a 4" Nike Smoke from MadCow shows an apogee of 111 ft and a max speed of Mach 0.05.

[blackbrandt]

Its not fiberglass, its phenolic and a reinforced paper cone. It weighs about 2.5 pounds fully loaded on the pad.

[chadrog]

Given that the max recommended liftoff weight for the E-18 is 16oz., and it will be really tough to get all five of your motors working together, I wouldn't try it.

[blackbrandt]

What about an E-30 and 2 E-18's? Would that be better?

[chadrog]

What about an E-30 and 2 E-18's? Would that be better?

That would be better - but... Yes, there's a but. With that arrangement you're dealing with two different propellants - one that lights very fast and easy, and one that gets going a bit slower and is known to be stubborn. I'd be leary of the E30 pulling the rocket away before the E18's get lit.

[blackbrandt]

All of the motors are Blue thunder, and I will paint some pyrogen on each First-fire igniter. Not only that, I am using a 6 foot long 1/4 inch stainless steel launch rod.

[chadrog]

All of the motors are Blue thunder, and I will paint some pyrogen on each First-fire igniter. Not only that, I am using a 6 foot long 1/4 inch stainless steel launch rod.

E18's are White Lightning propellant, and Blue Thunder shouldn't need any augmentation.

[blackbrandt]

Oh, sorry. but should that be good for thrust?

[chadrog]

That would be better, but getting them to all work together might still be an issue. I would recommend changing the E18's to E28's (or better yet F39's) for stronger kick off the pad and a better chance of successful cluster ignition. With either of those configurations you are using all Blue Thunder loads, and they are your best bet for successful composite clustering.

[blackbrandt]

What would be the size for decals on a 4 inch Smoke?

[crossfire]

Call Mad Cow Rocketry they have a 4" Smoke and have decals for them.
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