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General Rocketry Discussion!
- Thread starter Weldo
- Start date
- Joined
- Sep 7, 2019
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- 674
Haha, I can imagine. They don't tell you that at the max power level the parts will self destruct in a few minutes!
Stuff like that is where I think the domestic machines are better. Things like CNC routers, 3D printers and such, most likely they all use Chinese parts anyway but with the American built machines you get a bit more assurance that it's gonna do what it's advertised to do and like you said, you get at least some support.
What awesome capability it gives you though! I can imagine having a CNC mill, small laser cutter and a 3D printer, you could make literally anything!
Stuff like that is where I think the domestic machines are better. Things like CNC routers, 3D printers and such, most likely they all use Chinese parts anyway but with the American built machines you get a bit more assurance that it's gonna do what it's advertised to do and like you said, you get at least some support.
What awesome capability it gives you though! I can imagine having a CNC mill, small laser cutter and a 3D printer, you could make literally anything!
- Joined
- May 16, 2016
- Messages
- 1,695
Used to make rockets many years ago in the late '50's. rolled our own tubes using broomsticks for cores..
We put one layer of lunch wrap around the stick so we could get the tube off. then 3 or 4 wraps of Alfoil to shield the paper from the heat, then wrapped with brown packaging paper using water based hobby type glue, the first layer of paper was interleaved with the last layer of Alfoil.
Once it was all glued up we removed it from the rod and stuffed it with fuel Did try some home made black powder, but usually exploded right after lift off.
Read about Zinc and Sulphur, did many experiments with this fuel, various mixes, don't remember the results of different mixes but had various results, from failed to launch, exploded after lift off, and some went up into the sky completely out of sight never to be seen again.
We thought we were pretty sophisticated, but we were only school kids about 14 or 15 at most, but we were pretty pleased with ourselves at the time.
We put one layer of lunch wrap around the stick so we could get the tube off. then 3 or 4 wraps of Alfoil to shield the paper from the heat, then wrapped with brown packaging paper using water based hobby type glue, the first layer of paper was interleaved with the last layer of Alfoil.
Once it was all glued up we removed it from the rod and stuffed it with fuel Did try some home made black powder, but usually exploded right after lift off.
Read about Zinc and Sulphur, did many experiments with this fuel, various mixes, don't remember the results of different mixes but had various results, from failed to launch, exploded after lift off, and some went up into the sky completely out of sight never to be seen again.
We thought we were pretty sophisticated, but we were only school kids about 14 or 15 at most, but we were pretty pleased with ourselves at the time.
Last edited:
- Joined
- Sep 7, 2019
- Messages
- 674
Man that's really cool! Those really were the wild west days of rocketry!
Seems like these days the government is so busy protecting us from ourselves that if you did such fuel experiments today you'd at minimum get a hefty fine, or at worst be labeled as a terrorist!
On another note, what a great thing for 15 year old kids to be doing! Building your own rockets, experimenting with different fuels, I think that's really cool! Most 15 year olds today can't put down their smart phones long enough to even watch a rocket launch!
Seems like these days the government is so busy protecting us from ourselves that if you did such fuel experiments today you'd at minimum get a hefty fine, or at worst be labeled as a terrorist!
On another note, what a great thing for 15 year old kids to be doing! Building your own rockets, experimenting with different fuels, I think that's really cool! Most 15 year olds today can't put down their smart phones long enough to even watch a rocket launch!
Making motors is still an option, but we don't recommend those types. There are better choices now that are far more stable. Zinc/Sulphur in particular is impressive when it works, but fails far too often.
You can even use them at organized launches that use Tripoli rules and insurance. The most common are APCP, sugar and hybrids. APCP is the same basic design as a shuttle SRB. Sugar is less powerful but a lot cheaper. Also seems harder to get right in larger sizes. Hybrid keeps oxidizer separated until the burn. Usually it's a plastic or paper fuel grain and Nitrous Oxide. Liquid Oxygen is used by a few people as well.
I think it's a bit specialized for this forum though. And I'm not an expert in the design or building of them. I suggest joining Tripoli and working with some locals to learn how to do it safely.
You can even use them at organized launches that use Tripoli rules and insurance. The most common are APCP, sugar and hybrids. APCP is the same basic design as a shuttle SRB. Sugar is less powerful but a lot cheaper. Also seems harder to get right in larger sizes. Hybrid keeps oxidizer separated until the burn. Usually it's a plastic or paper fuel grain and Nitrous Oxide. Liquid Oxygen is used by a few people as well.
I think it's a bit specialized for this forum though. And I'm not an expert in the design or building of them. I suggest joining Tripoli and working with some locals to learn how to do it safely.
- Joined
- Sep 7, 2019
- Messages
- 674
Y'know ever since I started fooling around with rockets I've been curious about hybrid motors. I've done a little research on the subject, just enough to be dangerous!
I'm wondering if one could machine a small aluminum tank for a small charge of nitrous oxide and connect it to a machined fuel grain holder via a small solenoid valve. The fuel grain could be maybe paraffin wax cast into a machined tube. The idea is intriguing and possibly a cool way to bring machining into the hobby.
I'm wondering if one could machine a small aluminum tank for a small charge of nitrous oxide and connect it to a machined fuel grain holder via a small solenoid valve. The fuel grain could be maybe paraffin wax cast into a machined tube. The idea is intriguing and possibly a cool way to bring machining into the hobby.
One of my goals is to build a hybrid motor. I already have a nice tube with snap ring grooves and will be building the nozzle, closures, and valve. I'm planning on starting with a floating type called a U/C valve. It's reasonably simple machining, I'm still working on building my skills but I think I'm close on that side. I'm still working on the math to get the flow rates correct and such. And it will be tested from a very safe distance, and possibly on the other side of a cinder block wall. Assume it will go poorly. Then you're prepared and safe. There are a few guys on the Rocketry forums that are willing to help check the math and such. This will be physically larger than the M900 motor I posted about before. These are energetic devices and need to be treated with respect.
I own a few commercial hobby hybrid motors. My first try machining parts will be based on those.
I own a few commercial hobby hybrid motors. My first try machining parts will be based on those.