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Re: 3D printed rocket contest at MRRF!

Posted: Sun Jan 10, 2016 6:33 pm
by Eaglezsoar
I never knew that the "beyond hobbyist" market would have rockets that sophisticated. I'm almost 64 but I still learn something new each day!

Re: 3D printed rocket contest at MRRF!

Posted: Sun Jan 10, 2016 6:49 pm
by Xenocrates
Got a few smaller rockets kinda like that out in the barn. Things like a 6ft AIM-120 AMRAM. Then there are the folks I know with things like a family of V2's of various scales. They have one rocket that looks like a giant 12 foot crayon, which has 5 motor slots, and 3 separate charges for chutes and other things. While my dad was in the navy years ago, they had GPS steered parasails on some of their rockets (Which was cheating a bit, as at the time no one else had GPS, and he worked at China Lake)

You'd be surprised with what can be made, and what's been launched (portable toilet for example)

Re: 3D printed rocket contest at MRRF!

Posted: Sun Jan 10, 2016 7:11 pm
by teoman
I got the ingredients to make shugar rockets and i have a pretty good idea on how to make the material, but I have not been able to find a good guide for 3d printed rockets. One that also includes the motor (atleast the motor size).

Are there some rockets that you add the fuel in to the rocket rather than making a solid rod and then sticking it in to the rocket?

Re: 3D printed rocket contest at MRRF!

Posted: Mon Jan 18, 2016 7:49 pm
by rehabmax
Looks like you used some big boy engines in that. D or E single or cluster? What did the rocket weigh?

Re: 3D printed rocket contest at MRRF!

Posted: Tue Jan 19, 2016 12:25 am
by U.S. Water Rockets
Sheaffer wrote:I generally get them back. Especially the big ones like this - they are a pretty big "investment" both dollars-wise and time-wise. Either GPS or other tracking methods help a lot.

I actually got this particular rocket back one time 3 miles from the launch site after the main chute deployed at apogee (it's not supposed to).

Big rockets like this use a dual deployment system. An altimeter senses when the rocket reaches zero acceleration (apogee at the top of the ascent) and then fires a charge that separates the rocket and deploys a small parachute. The rocket then drops quickly, but under control, to a pre-set altitude. Then a second charge is fired and the main chute(s) are deployed, slowing the rocket so that it is not damaged when it lands (theoretically). The idea is that while the rocket is dropping quickly, it has less chance to drift too far from the launch site.

That's a nice looking launch. Very impressive! It's good to meet another rocket enthusiast involved in 3D printing on this site.

There are similar rules governing the launch of Water Rockets, set up by the WRA2 organization. The safety guidelines are very similar. The notable difference is that pyrotechnics are not allowed, so we have to employ electromechanical or other non explosive mechanisms for deploying parachutes, making it a bit different. We use a custom made barometric altimeter we designed, which activates and R/C servo to trigger our recovery system. This same altimeter hardware can be used for stage separation, or multiple parachute recovery, and other creative things.

We have toyed around with GPS, but we have had issues with the antennas breaking under high g-loading. Our typical tracking system is a simple 433Mhz beacon we also designed, which we can triangulate on using a directional antenna on our receiver. It works really well, and has located our rocket about 1/2 mile away in a thick wooded area.

Using this setup to locate our rocket that drifted so far is about as rewarding as any of our best launches.

The secret most people don't know is that a relatively small water rocket made from inexpensive materials is capable of lifting a very heavy payload several hundred feet in the air, so they are great for lofting cameras and experiments.

I'm looking forward to see what you can do with 3D printing and rockets!