3d Print Challenge

Hello Rocketry Forum people!

I work at a company which makes 3d printers, and some of the employees recently decided to have a printed rocket contest.

The engine we have to use is the c6-5.

It needs to be fully printed, other than the hardware for the parachute, shock cord, engine mount, and whatever else is involved. We have to be able to retrieve the rocket after launch. I guess the winner will be whoever's flys the highest, but most of the focus is actually getting a bunch of people making rockets.

I have looked up the specs for it, understand the very basics of begininng launch weight for the engine and rocket combo, etc.

What I need to find is a kit for the engine mount and parachute, and maybe any recommendations about what I should aim for hardware wise.

The design has to be all me.

I haven't launched a rocket in maybe 20 years.

The C6-5 has an outside diamater of 18mm. The only kits I can find seem to be for B, D, and E engines.

Some of the B engine kits state they can fit 18mm engines, so maybe I should go for that?

Thanks in advance for any help!

-Jordan

A,B and C engines are all 18mm engines. you can fly any of these three in a rocket with a 18mm motor. Here is a great kit that has everything you need https://www.estesrockets.com/rockets/kits/skill-1/001261-baby-berthatm

conman13 said:

A,B and C engines are all 18mm engines. you can fly any of these three in a rocket with a 18mm motor. Here is a great kit that has everything you need https://www.estesrockets.com/rockets/kits/skill-1/001261-baby-berthatm

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Sweet, thanks!

Good idea to buy a whole kit.

I like this contest. I have thought about it as a forum contest in the past.

D21 is 18 mm.

Motor mount of abs will stand up fine, plenty of guys on YouTube with printed rockets. So if you can do the modeling, no need to even buy a kit. All you would need is the recovery gear, and you can make that from household stuff easily.

Or go really fancy with a helicopter recovery, and print that too!

Hmmmmmmmm

You should be able to print the rocket airframe as a single part, tube and fins and all, and just print the nose cone separately. If you don't plan to fly it a bunch of time, you might be able to work the engine hook into the tube between two fins. Two narrow slots about an inch long side by side would leave a strip that could act as a hook if you add a bend at the lower end. Print the thrust ring too, and anchor the shock cord through a pair of narrow parallel slots in the body tube. It wouldn't be the prettiest rocket, but it would be really simple to assemble and fly.

You could feasibly print everything short of the shock cord and parachute. I printed a three-segment rocket with the motor mount and most of the tie-in points already printed. (I forgot to include a forward tie-in point for the shock cord. Whoops. I was able to find a small eye bolt to screw in instead.) Just don't make interior parts too thin, lest they melt from the ejection charge. I would say 1 or 2mm is generally a sufficient thickness.

Be warned that you may want to line the motor tube with a traditional tube material as one of the guys in my club learned that the heat from the motor melted the printed material effectively welding the motor in.

I am building a rocket on Tinkercad - https://tinkercad.com/ - I also forgot eyelets on my first full printed iteration, hope to rebuild it this week!

BuitlFromTrash

alex_car763 said:

Be warned that you may want to line the motor tube with a traditional tube material as one of the guys in my club learned that the heat from the motor melted the printed material effectively welding the motor in.

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The only problem I ever had with heat was the melting of my aft tie-in point for the shock cord. I was able to remove my motor from the printed mount (min-diameter, so also airframe) no problem. I printed in PLA. What material did your friend use?

jmattingly13 said:

The only problem I ever had with heat was the melting of my aft tie-in point for the shock cord. I was able to remove my motor from the printed mount (min-diameter, so also airframe) no problem. I printed in PLA. What material did your friend use?

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Thanks for the advice, everyone!

I am lucky to be able to use a projet 3500 rather than an FDM. I will probably be printing several iterations of the body and cone.

The idea of having a traditional inner engine mount tube is good, but there is going to be a balance between body diameter and weight that I will be fighting against.

I will update.

Again, thank you all.