Looking to build a 29mm minimum diameter rocket - I have a few questions..

Andrew do you live close to Dayton Ohio. I seen you had videos from the TMO launch. If so you could also come up to erockets in North Dayton. Every Tuesday night we have a build session with a bunch of builder to give you a hand.
I just built an almost min diameter but I choose to use a BT-55 tube. This allowed for tiny through the wall fins and more nose cone options.
It is built for an F10 and projected around 4200'. But could handle an I200 to about 7000'. But packing everything in a 29mm rocket (altimeter and GPS) is tough. My GPS fills my NC on my Rocket built around a BT-70. So for me I'm sticking with the F10 a sweet slow 8 seconds of thrust and no electronics so if it doesn't come back I'm out $20 worth of parts.

jdbwizzard said:

Andrew do you live close to Dayton Ohio. I seen you had videos from the TMO launch. If so you could also come up to erockets in North Dayton. Every Tuesday night we have a build session with a bunch of builder to give you a hand.
I just built an almost min diameter but I choose to use a BT-55 tube. This allowed for tiny through the wall fins and more nose cone options.
It is built for an F10 and projected around 4200'. But could handle an I200 to about 7000'. But packing everything in a 29mm rocket (altimeter and GPS) is tough. My GPS fills my NC on my Rocket built around a BT-70. So for me I'm sticking with the F10 a sweet slow 8 seconds of thrust and no electronics so if it doesn't come back I'm out $20 worth of parts.
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I live in the Cincinnati area. I would really like to go to the Erockets build night, but I don't have the time.
You MD rocket looks great!! Just the other day I saw your newest video on YouTube!!

Looking good so far!!
I got RockSim Trial. I have been messing around with different designs. And I think I found "THE ONE!"

DIMENSIONS AND OTHER INFO:
Body Tube: 14 inches long. 29mm diameter
Nose cone: Conical nose 6 inches long. 1 inch shoulder
Fins: 1/8 plywood OR 1/4 inch plywood (3 Fins)
Eletronics: PerfectFlite APRA, Pratt Hobbies MicroBeacon
Recovery: 12 inch mylar (silver) parachute, Kevlar cord
Glue: 30 Minute epoxy, 5 minute epoxy
Motor: AT DMS H135W
Altitude & Speed (Estimates) Around 9K-9.5K. Speed, Mach 1.5
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NOTES: I sent in my TRA membership form today! I'm going for a record!!!!!
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Hmm, I think I see a build thread coming soon!



Thanks,

Good luck!

For the screen images there is a 'snipping tool.' (press the icon in the bottom left corner of the page and search for it.)
Note that barrowman calculations only work well up to ~Mach 0.5 and Rocsim's figures are usually overestimated.

FYI the H45 is a 38mm motor. Long burns in a light rocket should give you great altitude.

jdbwizzard said:

Andrew do you live close to Dayton Ohio. I seen you had videos from the TMO launch. If so you could also come up to erockets in North Dayton. Every Tuesday night we have a build session with a bunch of builder to give you a hand.
I just built an almost min diameter but I choose to use a BT-55 tube. This allowed for tiny through the wall fins and more nose cone options.
It is built for an F10 and projected around 4200'. But could handle an I200 to about 7000'. But packing everything in a 29mm rocket (altimeter and GPS) is tough. My GPS fills my NC on my Rocket built around a BT-70. So for me I'm sticking with the F10 a sweet slow 8 seconds of thrust and no electronics so if it doesn't come back I'm out $20 worth of parts.
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We flew a few Estes Pathfinders on F10s. Very nice fight / motor. Again not a huge lose if you lose it. Might want to go with streamer recovery if the rocket is light enough.

cavecentral said:

FYI the H45 is a 38mm motor. Long burns in a light rocket should give you great altitude.

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Oops, Sorry! I didn't realize

cavecentral said:

FYI the H45 is a 38mm motor. Long burns in a light rocket should give you great altitude.

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Do you think a 12 inch mylar parachute is not enough??
Thanks,

rockets said:

Do you think a 12 inch mylar parachute is not enough??
Thanks,

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Depends on the rocket and your flying area (landing surface and how much room you have). Needs to decent at a safe speed for the weight of the rocket. I'd rather crack a fin on landing from a smaller chute / streamer than lose a rocket. If it goes out of sight without a tracker, you may never find a small rocket and drifting under a large chute doesn't help.

For many nylon chute brands, the manufacturers provide decent rate charts for different weight rockets or size recommendations. Example: https://topflightrecoveryllc.homestead.com/descent_rates.html

cavecentral said:

Depends on the rocket and your flying area (landing surface and how much room you have). Needs to decent at a safe speed for the weight of the rocket. I'd rather crack a fin on landing from a smaller chute / streamer than lose a rocket. If it goes out of sight without a tracker, you may never find a small rocket and drifting under a large chute doesn't help.

For many nylon chute brands, the manufacturers provide decent rate charts for different weight rockets or size recommendations. Example: https://topflightrecoveryllc.homestead.com/descent_rates.html

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OK, I'm going to fly at a corn field.

rockets said:

OK, I'm going to fly at a corn field.

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Spring / early summer before corn is high. Finding them in corn is tough! Once it grows, the area feels like you are walking through a sauna.

cavecentral said:

Spring / early summer before corn is high. Finding them in corn is tough! Once it grows, the area feels like you are walking through a sauna.

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Yeah, You got that right Kevin. I once lost an Estes "canned" (easy to build) Eliminator on an RMS 24mm motor
early in my flying and was really bummed. It was in a no-till cornfield. Later in the season, I flew a rocket with
an aural device and it went down in the corn. I was triapsing to that rocket and happened to stumble into the
Eliminator I lost earlier in the season. The corn had grown up around it and actually the lime green nylon chute
caught my eye. Of course I grabbed it and realized it was mine, The tube was melted away after being subjected to multiple rains but the nylon chute, plastic fincan, nosecone and the RMS motor casing, I got back! The motor was really the issue to recover. I did recover the rocket I was originally going after. Kurt