A bunch of questions

[KimYoungMuri]

Hey everybody!

I'm currently trying to build a TVC (Thrust Vector Control) rocket. I have a lot of past experience with electronics and physics, but not so much in rocketry as a whole. I had a few general rocketry related questions that I was hoping you guys can answer! Thanks!

1. I'm trying to make the piston ejection system that Joey (BPS) uses in his rockets. If you goto 8:18 you see his ejection charge, but I wasn't sure where I can get these? Someone said they're firework igniters (e-matches) but I didn't have success finding them online. Can you send an amazon, apogee components, etc. link to where I can get something like the pyro charge wire he's using?

2. I'm also trying to make my own rocket launchpad! I believe (and correct me if I'm wrong) regular rockets use starters and starter plugs in the rocket engine and connect them to alligator clips to create enough heat to start the engine. But if you goto 4:27 in this video: , you can see that instead of something like a starter, Joey uses some kind of flame in his launchpad. I was wondering what this was, and where I can find something like this? Please send links, I might accidentally buy something completely different hehe. (better footage of these pyro wires: )

Thanks so much!

 

[afadeev]

I'm currently trying to build a TVC (Thrust Vector Control) rocket. I have a lot of past experience with electronics and physics, but not so much in rocketry as a whole. I had a few general rocketry related questions that I was hoping you guys can answer!

You really need to build general awareness of rocketry, before you dive into the deep end of the pool with electronic ejection, thrust vectoring, etc.

Go to a local hobby store, but a starter Estes kit with a launch pad, build it, fly it a few times. About $35 should give you answers to at least 2 of your questions, some experience, and a lot of confidence to proceed.
Then come back with the remaining question, and we'll point you in the right direction, if you are still interested.

If you really want to get your TVC rocket to fly, be prepared to spend $400-600, and really apply the experienced you gained above.
Watching YouTube videos alone will not cut it.

HTH,
a

 

[aerostadt]

There are a few people ahead of you in line. A search of "TVC" or "thrust vector control" here on TRF will find a lot of them. The person that I think is probably farthest along is:

https://bps.space/tvc

 

[PayLoad]

I am NOT being a wet blanket here - Someone please explain the usefulness of thrust vector control on a motor that burns for 3 seconds please? The idea is cool, but by the time the electronics figure out what is going on, the motor has burnt out.

 

[afadeev]

I am NOT being a wet blanket here - Someone please explain the usefulness of thrust vector control on a motor that burns for 3 seconds please? The idea is cool, but by the time the electronics figure out what is going on, the motor has burnt out.

On either a 3.5 seconds (F15), 7.0 seconds (F10), 15.2 seconds (H13), or 16 seconds (G8) motors, the answer is still the same - it's a cool "under thrust" gimmick.
The gravity always wins in the end.

The relative coolness of what happens between pressing the ignition start button and recovering the rocket, is highly subjective.
Fooling around with TVC is one of the way to keep interest in this hobby alive and well. But definitely not a good entry point into it.

 

[Scott_650]

I am NOT being a wet blanket here - Someone please explain the usefulness of thrust vector control on a motor that burns for 3 seconds please? The idea is cool, but by the time the electronics figure out what is going on, the motor has burnt out.

Aerotech’s 15 second burn time 29mm H13 could be just the ticket for something like this. Joe Barnard’s vertical landing under thrust setup uses a separate motor for the landing phase by popping the initial motor out of the way. Think of all the awesome configurations you could fly with active stability and powered landings! This may never end up as a part of mainstream hobby rocketry but it’s fascinating.

 

[KimYoungMuri]

You really need to build general awareness of rocketry, before you dive into the deep end of the pool with electronic ejection, thrust vectoring, etc.

Go to a local hobby store, but a starter Estes kit with a launch pad, build it, fly it a few times. About $35 should give you answers to at least 2 of your questions, some experience, and a lot of confidence to proceed.
Then come back with the remaining question, and we'll point you in the right direction, if you are still interested.

If you really want to get your TVC rocket to fly, be prepared to spend $400-600, and really apply the experienced you gained above.
Watching YouTube videos alone will not cut it.

HTH,
a

Hey,

Thanks for the reply! Yeah, I definitely see where you're coming from and do think the first-hand experience would be the best. I'll give you a bit of context to give you a bit of perspective, and maybe you can consider answering the questions! So I'm currently residing in a country where rocketry isn't big at all (contrary to the US), and I've been looking somewhere where I can get something like an Estes kit but with no success. No rocket engines or kits ship internationally either, so I honestly don't have an option. Trust me, I really tried. But I'm currently a rising senior in high school and I'll be off to college in the states in about a year. I was thinking that I can at least build the rocket body, electronics (I already finished all the electronics for the flight computer, including the flight software), launchpad, and pretty much everything else so that as soon as I get to the states and get a flying license, I can buy any HAZMAT required parts and start flying. So please, I'd really appreciate if you can help me out by answering those questions. P.S., I already spent around $300 on electronics and the rocket body. I'd say it's sorta too late to drop this project lol.

 

[tsmith1315]

If you go to 8:18 you see his ejection charge, but I wasn't sure where I can get these? Someone said they're firework igniters (e-matches) but I didn't have success finding them online.

That's an e-match or starter with a little packet of (probably) black powder attached to it. Be careful of regulations, e-matches are regulated by the ATF in the US except for the Firewire here at MJG, also here: Firewire Initiator.

This is a Firewire with the protective cover pulled back to show the pyrogen:

you can see that instead of something like a starter, Joey uses some kind of flame in his launchpad. I was wondering what this was,

That is indeed a motor starter, held in launch position by an alligator clip for the video demonstration. You can see the same orange wire from his other video running off to the left:




I strongly encourage you to read up on the safety protocols which have allowed us to enjoy our hobby for decades. Without them, there's a good chance that we wouldn't be able to get rockets and motors here either.

The National Association of Rocketry and Tripoli Rocketry Association are the organizations involved.