Hello from Arizona, trying to get into HP rocketry

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JohnT

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Nov 22, 2024
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Chandler, AZ
Hello all,
I've gotten back into this hobby after a >20 year break. I restarted the hobby as I still enjoy model rocketry, and I now have a two-year-old son who seems to share the passion. I quit flying model rockets around 1999 ish at the age of around 15-16 for a number of reasons, a big one being it was just too difficult to find a place to launch them. 24 years go by, I'm now living in Arizona, and big open publicly accessible places are everywhere :)

I presently fly Aerotech kits with F and G motors, but I'd like to get into high power rocketry. There's a club in based in the PHX metro area that has monthly rocket launches (I'm guessing they have to take the summers off), but sadly their launch site is like halfway to California and a 2+ hour drive away. I'll make it one of these months. The issue is of course my parental duties don't make me feel comfortable basically slacking off and forcing the wife to take care of the kids for basically a whole day. On the other hand, I could bring my son, he's almost 3 now, but I'm not quite sure he's ready yet for a 2 hour one-way drive out to see some high power rockets. He really does enjoy rocket launching with daddy but since the lift-off sound G motor still does scare him a little bit, I'm not sure he could handle something like a K motor. I want to get the kid excited about rockets and STEM, not traumatize him.

Anyway, I was kind of thinking of creating a 4" diameter high power rocket with a modular engine mounts that could be swapped out to fly both clusters or single motors. I could perhaps fly it on a 2X G64W cluster and use electronics to deploy a chute prove out its design and functionality before switching it to a single 38 mm or single 29 mm H or I motor to cert with. Obviously I'd have to pay attention to CP and CG and all that, but I think I can make a robust airframe and method to distribute flight forces even though the entire engine mount isn't technically glued to the airframe, just slotted in and rotated (and screwed). (The engine mounts will rest against multiple things that ARE glued and that certainly won't be coming loose.) Really, the idea I have in my head is not to make a singular rocket per se, but actually to create a series of modular components that can be assembled into a rocket, and then re-assembled into a different rocket. Not only does it allow for flexibility but in the event of a crash, most likely many or most of the modules would survive undamaged or at least be repairable.

I thought I read that 2X G64W wouldn't require a cert to fly at an event, though I might be pushing up against some FAA limits? I'd basically just like to fully test my idea out before going for the cert, 2X G64Ws would be similar/identical in thrust and total impulse to an H.

It's probably overkill, but the first thing I'm doing is creating a 100A, 12V launching system using IGBT's (a type of high-power transistor). I'm guessing that 100 A is probably overkill and unnecessary even for flying medium/high power clusters but being an electrical engineer, I just like building electrical things :) Also, since IGBTs are voltage controlled, I can put the car battery right next to the launch pad and trigger the IGBTs with a hand controller on a really long wire (I purchased 50' cable for the test and ignition signals). Also, that of course allows for lower conduction losses while conducting 100 A of launch current, and makes it easier/cheaper to use a really stiff and wide cable to conduct the launch current. I wanna instantly vaporize my ignitors, even if there's like 5 of them in parallel :) Maybe I could even make a later variant of the launcher that triggers using bluetooth and a smart phone app, that would be kind of cool.

Anyway, thanks for having this community available so that I can learn from the knowledge and mistakes of all of you more experienced rocketeers :)
 
vaporizing ignitors does not work well, even with Black Powder let alone APCP motors.

You need First Fires dipped in Procast for clusters of AP, and e-match "BP Starters" for clusters of Black Powder motors for a 'sure fire'

Animal Motor Works is in your area to drive to, they should be able to set you up on ignitors and motors without shipping or hazmat costs

https://cart.amwprox.com/
 
vaporizing ignitors does not work well, even with Black Powder let alone APCP motors.
This. BP is sensitive to spark and flame; even the short 'pop' of an e-match is sufficient to ignite it. APCP needs a long-burning motor starter. At very high amps you may find that both motor starters in an APCP cluster will pop without ignition. Or worse, one ignites the propellant, the other does not...

A lot of guys who (like me) build their own launch system will use a 50' or 100' extension cord to connect the controller to the pad. Readily available, inexpensive, easily replaced at any hardware store if damaged.

Consider bringing the kid(s). Have over-the-ear hearing protectors if needed. Easier to 'install' than earplugs when dealing with a wriggling two-year-old.:) Baby backpack to keep him from wandering where he shouldn't.
 
Phoenix area parks are limited to a B engine. To launch anything larger requires a remote county location with landowner permission. This is why a club launch is helpful. SSS flies mostly model rockets with a few higher power rockets.
 
I thought I read that 2X G64W wouldn't require a cert to fly at an event, though I might be pushing up against some FAA limits?:)
2x G64 will be just a hair over the Class 1 FAA limit of maximum propellant weight, and would require a waiver to fly. technically.

It's quite easy to build a rocket that will fly on a single G or a single H. I wouldn't worry about a slight difference in total thrust. Clusters come with their own problems and IMHO are not worth the complication.
 
I assume if you have permission you can?
I contacted the Tohono Oʼodham Nation, large area south of Phoenix mostly flat desert. They were cool about it but unless we had a tribal member who lives on the rez directly involved it was unlikely we would get permission.
So we looked elsewhere.
 
I contacted the Tohono Oʼodham Nation, large area south of Phoenix mostly flat desert. They were cool about it but unless we had a tribal member who lives on the rez directly involved it was unlikely we would get permission.
So we looked elsewhere.
so it'd be a gov process not a them thing?
 
The tribal manager. With rockets in general. Had done in grade school
However, at the time (2000?) at least, the tribe didn’t allow non tribal members to do anything on the reservation without a lease on the land. No camping, hunting hiking, motorcycles…….anything. Agriculture, racetrack, industrial casino are all on long term lea$e$.
 
Personally, I like LOC kits. Not too expensive but go elsewhere because the shipping is a killer. This is the one I'm working on now but probably won't be ready for our 1/11 launch. It can take 29/38/54 motors.
https://cart.amwprox.com/index.php?..._id=1597&virtuemart_category_id=86&Itemid=482

I would start with JLCR for easy recovery. Later, you can get a LOC payload kit and use dual deploy with charges. Or better yet, build your own chute release or flight computer that ignites the drogue charge at apogee and main at 500ft or so. We had high schoolers who built their own CR in a 2in rocket. The H128W went to 2000ft. Landed in prickly thistles, so the teacher was covered when they got the rocket.

Micah was really nervous about launching for his L1. His classmates were running tests after tests on their classmade CR. Finally I said we're closing shop, and he begged to go. We loaded his motor and sent it on its way, successfully. He said afterwards, the process was very stressful and woulda been happy with the F50 in hindsight. Ah, youth...



The next question is NAR or TRA or both. I guess that depends on who can mentor you at the club launch and sign your certs.
 
. This is why a club launch is helpful. SSS flies mostly model rockets with a few higher power rockets.

I flew with the SSS club last month, it was overall a good experience. They had a good amount of HPR launches, short lines, and helpful, friendly, people there. It's quite a hike from Tucson, where i live, but i plan on going there more often this year. The Tucson club (SARA) is nice, but they have a pretty small field, and a fairly low waiver.
 
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