4 ms·

2015~2016 I spent some time with model rocketry, and SpaceX was very exciting to me at that time. I scratch-built a model Falcon 9 with the primary goal of act

by mawise 4y ago

2015~2016 I spent some time with model rocketry, and SpaceX was very exciting to me at that time. I scratch-built a model Falcon 9 with the primary goal of actually using a cluster of 9 motors[1]. I had access to a friend's 3d printer for the nose and landing legs. I ordered laser-cut parts for the motor mounts and other details like the grid-fins. I even printed out custom decals and spent some time on the paint job. The timing worked out that I got to enter it in the local model rocketry club's "sport scale" contest, and the judge dinged me for having windows--at that time there was no crew dragon that had flown. (I still won the contest). The rocket has only flown once, but I still have it. Eight of the nine A10-3T motors lit, and the chute deployed just before hitting the ground. It really could use a shorter delay time but you don't have many options with motors of that size. I had ambitions of building a falcon heavy, but I really wanted the boosters to fall off and have the central core continue under thrust. Then I had kids and haven't had time for rockets, but I still have hopes of doing that build--probably with high-power motors--at some point in the future. [1]: https://imgur.com/PBdyEmA https://imgur.com/PBdyEmA

mustacheemperor 4y ago
That is so cool. Thank you for sharing. Model rocketry is maybe the one thing I miss the most after moving to California. Between airspace regulations and wildfire risk, I don't think it's something I can really do without a long drive to the desert. I guess it probably wasn't really allowed for us to go do it in fields in rural New England either, but that felt different.
- unixhero 4y ago
  Nevada isn't that far away is it?
- mawise 4y ago
  Check out Lunar[1], they used to do low power launches at Moffett, and high power ~2 hours east of there. I'm not sure what they do these days. Wherever you are, there is probably an NAR club [2] which will be a great resource! [1]: http://lunar.org/ http://lunar.org/ [2]: https://www.nar.org/find-a-local-club/ https://www.nar.org/find-a-local-club/
grecy 4y ago
Woah, that's awesome. Do you have a video of it flying? I'd love to see that
perilunar 4y ago
> Then I had kids and haven't had time for rockets I got into model rockets after I had kids, when my then 5 year old son asked me if we could “build a rocket to go to the moon”. I suggested we start small and work our way up. He lost interest after several rockets and a hundred or so launches — well before we reached that goal. But it was a blast. We even had a birthday party with rocket launches and a moon shaped-cake. So my suggestion: build (small) rockets with your kids — they’ll love it!
IIAOPSW 4y ago
The trick is to get the kids interested in it, then have them build the rocket.
LorenPechtel 4y ago
I'm amazed you got a decent launch out of a cluster like that, it would be hard to get all of them to light before the first starts producing thrust. I think the parachute would have worked better with a B but I'm not seeing anything in their catalog that looks like a good fit. As for a heavy design--put high thrust engines in the sides and low thrust/longer burn engines in the core. The pieces are *not* attached, the core is basically riding on pins on the sides, when the sides burn out the core simply lifts off the pins. Arrange the fins on the sides so they have a desire to fly a bit off straight--once they separate they'll start to spin outward from the core and hopefully not get fried. Put some engines with a very short delay that blow out streamers and a longer delay (once the streamers have a chance to kill the spin) for chutes. I'm not sure how to build compartments for them, though, the standard deployment won't work. You'll need a very powerful ignition system to get everything to light close enough together.

by mawise 4y ago

mustacheemperor 4y ago

That is so cool. Thank you for sharing. Model rocketry is maybe the one thing I miss the most after moving to California. Between airspace regulations and wildfire risk, I don't think it's something I can really do without a long drive to the desert. I guess it probably wasn't really allowed for us to go do it in fields in rural New England either, but that felt different.

unixhero 4y ago
Nevada isn't that far away is it?
mawise 4y ago
Check out Lunar[1], they used to do low power launches at Moffett, and high power ~2 hours east of there. I'm not sure what they do these days. Wherever you are, there is probably an NAR club [2] which will be a great resource! [1]: http://lunar.org/ http://lunar.org/ [2]: https://www.nar.org/find-a-local-club/ https://www.nar.org/find-a-local-club/

grecy 4y ago

Woah, that's awesome. Do you have a video of it flying? I'd love to see that

perilunar 4y ago

> Then I had kids and haven't had time for rockets I got into model rockets after I had kids, when my then 5 year old son asked me if we could “build a rocket to go to the moon”. I suggested we start small and work our way up. He lost interest after several rockets and a hundred or so launches — well before we reached that goal. But it was a blast. We even had a birthday party with rocket launches and a moon shaped-cake. So my suggestion: build (small) rockets with your kids — they’ll love it!

IIAOPSW 4y ago

The trick is to get the kids interested in it, then have them build the rocket.

LorenPechtel 4y ago

I'm amazed you got a decent launch out of a cluster like that, it would be hard to get all of them to light before the first starts producing thrust. I think the parachute would have worked better with a B but I'm not seeing anything in their catalog that looks like a good fit. As for a heavy design--put high thrust engines in the sides and low thrust/longer burn engines in the core. The pieces are *not* attached, the core is basically riding on pins on the sides, when the sides burn out the core simply lifts off the pins. Arrange the fins on the sides so they have a desire to fly a bit off straight--once they separate they'll start to spin outward from the core and hopefully not get fried. Put some engines with a very short delay that blow out streamers and a longer delay (once the streamers have a chance to kill the spin) for chutes. I'm not sure how to build compartments for them, though, the standard deployment won't work. You'll need a very powerful ignition system to get everything to light close enough together.