Madcow 2.6" Fiberglass Nike-ASP

LDRS 38 got me wanting to try a 2-stage again. With this Madcow hump day special I could ease into it with a lower altitude rocket. However I would like to put a 29mm motor in the sustainer. What would be your suggestions for motor retainer for it? Also I would need to figure out how to get the motor lit since it would be a minimum diameter. Ideas?

davdue said:

LDRS 38 got me wanting to try a 2-stage again. With this Madcow hump day special I could ease into it with a lower altitude rocket. However I would like to put a 29mm motor in the sustainer. What would be your suggestions for motor retainer for it? Also I would need to figure out how to get the motor lit since it would be a minimum diameter. Ideas?

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It's a nice looking rocket and a great sale, but that 29mm upper stage will be a challenge for electronics and staging. The sustainer motor should be lit from the sustainer electronics, so you'd have to go with HEI (research) or run some flat wire down to the bottom from your AV-bay.

I'd suggesting sticking with 24mm, you can run a Cesaroni 6G in there and the 24mm will leave enough space to run wire down to the bottom from the AV-bay.

I would run a Eggtimer Proton in the AV-bay of the sustainer with an eggfinder in the nose. The Proton has 6 channels which allows you to run redundant charges and the sustainer ignition and a separation charge.

The I/S coupler in the booster would have an Eggtimer Quantum configured for apogee and apogee + 1 charges and a JLCR.

Madcow doesn't include the bulkheads needed to run the I/S coupler as a AV-bay, so you'll need to order those as well.

Hmm, I wasn't going to order this but now I'm thinking about it...

cheers - mark

Hmm, the sustainer is a little too short to have a traditional AV-bay. Looks like it would need to be HED, squeezing a Proton and eggfinder into an extended AVbay. I'm not sure of the space in the nosecone, might have to reverse the HED and put the main in the body. A thin mill chute will likely fit though.

My quick OR sim shows 3500ft for a Loki H144->Cesaroni F70.

Do I really need a 3rd two stage HPR?

What size main are you looking at?

mpitfield said:

What size main are you looking at?

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I'd guess the sustainer probably only needs a 24" chute. I'd fly it drogueless. The fins look like they'd have no problem with a quick descent.

I am looking at the same kit. Have you looked at the Fruity Chutes, thin mill 24" compact classic elliptical chute. A premium priced chute, but the quality and performance is second to none!

https://fruitychutes.com/buyachute/...20fps-p-169.html?zenid=56BPTgipmWIJ1KfC3Nuu00

It looks like a Proton won't fit in a 29mm coupler, so my new choice for sustainer ignition, separation and DD charges is a Raven 4. I'd then just clip an Eggtimer Mini on the shock cord for tracking.

Motor retention for the 24mm would be friction fit. Hang the MMT 1/2" out the back of the airframe to be able to have a wrap of tape around the motor.

To convert the booster transition coupler to an AV-bay, order an extra 2.6" / 66 mm Natural G10 AvBay Lid.

Hopefully this rocket sells out immediately so I'm not tempted to buy one tonight...

markg - did you get one or able to resist? I did order one ... excited to make it my first two stage rocket.

markg said:

Hmm, the sustainer is a little too short to have a traditional AV-bay. Looks like it would need to be HED, squeezing a Proton and eggfinder into an extended AVbay. I'm not sure of the space in the nosecone, might have to reverse the HED and put the main in the body. A thin mill chute will likely fit though.

My quick OR sim shows 3500ft for a Loki H144->Cesaroni F70.

Do I really need a 3rd two stage HPR?

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Would you be willing to share your .ork file? I have been looking online and haven’t been able to find anything.

Bill Hanson said:

Would you be willing to share your .ork file? I have been looking online and haven’t been able to find anything.

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Mine is only an estimate based on the specs on their web page. I don't have the parts on hand to measure / weigh yet. So take it for what it's worth.

cheers - mark