3D Printing 3D Printed Rocket - 3pcs, no glue.

[r-dub]

I picked up a Creality Ender 3s Pro a few months ago, and among several other projects, I thought it’d be cool to see how easily and reliably I could print a rocket.

Design was done in Fusion360, slicing done in Cura. Using data from Fusion and Open Rocket, stability looks good. Material is PLA, and my only concern is how the thin wall tube is going to stand up to ejection charge heat. I might look into coating the inside with a primer for this reason. I incorporated lots of neat features: full fin roots down to motor casing, strengthening internal ribs down tube length, aero lug, and a quick release motor retainer.

My main objectives were to use as few pieces as possible, and no glue. To that end, I printed fins, lug and shock cord mounts in place. The rocket is 3 printed pieces - nose cone, main body, and a motor retainer collar. I only had to add a 12” chute and shock cord to complete the rocket.

It’s a bit heavier than a standard cardboard / balsa build, but I’m certain the 3D printed fins are far more robust. I printed this prototype with 100% infill, but there aren’t really too many spots where a lighter fill could be employed. The only voluminous spots in the build are the motor bulkheads. I’m also not sure how many small closed pockets of air in the structure would react to rapid changes of altitude (ambient pressure).

When the weather improves a bit around here, I’ll give it a shot on a C6-3. More photos to come!

Cheers!

 

[thzero]

Nice looking rocket.

PLA softens in the direct sun.
PETG is better.
PLA Pro+ (such as eSun) can be as nearly as good.

Lot of the printed rockets I've seen do use a motor tube just to help keep the heat down. Otherwise, other than extremely boring 3NF rockets (instead of doing some bit wild to take advantage of 3d printing), there are a couple of folks at the clubs I launch with that have done similar size rockets with plenty of successful flights.

 

[r-dub]

So, first flight was a half success! Flight was perfect, super stable, straight as an arrow. As somewhat expected, my single wall body tube wasn’t strong enough to withstand ejection pressure, and it split along the seam. Rocket came down with parachute ejected but tangled. No further damage to the body on impact with hard gravel, so that was impressive.

There was definitely some heat damage to the thin wall tube where it split, but the motor casing area was perfectly intact. I think there’s enough material there to disperse the heat without melting.

Back to the drawing board, I redesigned with a thicker tube wall (1.2mm). I also sprayed the inside of the tube with silver metallic spray paint, in an effort to reflect ejection heat away from plastic walls. Great success! I had 3 flawless flights yesterday.

Next step is to print one out of PETG, maybe see if I can skip the interior spray coating. Really enjoying the challenges of this project, even if they are dinky little rockets. I’m a machinist by trade, and this is a great way to learn a bunch of new skills.

Cheers!


View attachment IMG_8053.MOV

 

[r-dub]

Nice looking rocket.

PLA softens in the direct sun.
PETG is better.
PLA Pro+ (such as eSun) can be as nearly as good.

Lot of the printed rockets I've seen do use a motor tube just to help keep the heat down. Otherwise, other than extremely boring 3NF rockets (instead of doing some bit wild to take advantage of 3d printing), there are a couple of folks at the clubs I launch with that have done similar size rockets with plenty of successful flights.

Forgive my ignorance, but what does 3NF mean? Something about 3 fins?

 

[thzero]

Forgive my ignorance, but what does 3NF mean? Something about 3 fins?

3 fins and a nose cone

 

[RocketMan3D]

So, first flight was a half success! Flight was perfect, super stable, straight as an arrow. As somewhat expected, my single wall body tube wasn’t strong enough to withstand ejection pressure, and it split along the seam. Rocket came down with parachute ejected but tangled. No further damage to the body on impact with hard gravel, so that was impressive.

There was definitely some heat damage to the thin wall tube where it split, but the motor casing area was perfectly intact. I think there’s enough material there to disperse the heat without melting.

Back to the drawing board, I redesigned with a thicker tube wall (1.2mm). I also sprayed the inside of the tube with silver metallic spray paint, in an effort to reflect ejection heat away from plastic walls. Great success! I had 3 flawless flights yesterday.

Next step is to print one out of PETG, maybe see if I can skip the interior spray coating. Really enjoying the challenges of this project, even if they are dinky little rockets. I’m a machinist by trade, and this is a great way to learn a bunch of new skills.

Cheers!

View attachment 558293
View attachment 558294

I would recommend using random seams and PETG.

 

[thzero]

I would recommend using random seams and PETG.

Just PETG won't help in that small of body. Using a cardboard body tube is better or even sheet of paper. ABS and ASA are a bit better. The bp charge is rather hot.

Bit surprised you didn't have any warping in motor mount area. I use a motor tube to avoid issues, or other replaceable sleeves. Estes motors are pretty hot.

I've not had issues with .8" PETG walls and ejection charges this far at 54mm diameter and up.

While using non linear seam helps, that it split lit that tells me the nose cone was on too tight and the seam was the path of least resistance.

 

[wsume99]

IMO cardboard or FG are going to do a much better job than a 3D printed body tube. All the rockets where I've used printed components utilize a cardboard BT with a printed NC and fin can. Could I print a BT, absolutely. If I made it as strong as cardboard it would be significantly heavier. If I made it as light as possible, even a single wall BT will be heavier than cardboard, it's going to be much weaker than cardboard. Cardboard BTs are relatively cheap, readily available and easy to work with. I just don't see the benefit of using a 3D printed body tube beyond being able to say I made an entirely 3D printed rocket. I know I can do it but it just seems like a waste of time to me personally seeing as how there are much better alternatives out there.

 

[SolarYellow]

Forgive my ignorance, but what does 3NF mean? Something about 3 fins?

3 fins and a nose cone

Should be "3FNC," "4FNC," or "3/4FNC."

IMO cardboard or FG are going to do a much better job than a 3D printed body tube. All the rockets where I've used printed components utilize a cardboard BT with a printed NC and fin can. Could I print a BT, absolutely. If I made it as strong as cardboard it would be significantly heavier. If I made it as light as possible, even a single wall BT will be heavier than cardboard, it's going to be much weaker than cardboard. Cardboard BTs are relatively cheap, readily available and easy to work with. I just don't see the benefit of using a 3D printed body tube beyond being able to say I made an entirely 3D printed rocket. I know I can do it but it just seems like a waste of time to me personally seeing as how there are much better alternatives out there.

^^^What he said. Even just rolling up some nice bond printer paper a few wraps and taping the inside and outside seams would likely be just as good if not better. Add some white glue, and you're rockin'.

Or buy tubing. Standard Estes sizes are super cheap compared to any other aspect of this hobby.

 

[thzero]

IMO cardboard or FG are going to do a much better job than a 3D printed body tube. All the rockets where I've used printed components utilize a cardboard BT with a printed NC and fin can. Could I print a BT, absolutely. If I made it as strong as cardboard it would be significantly heavier. If I made it as light as possible, even a single wall BT will be heavier than cardboard, it's going to be much weaker than cardboard. Cardboard BTs are relatively cheap, readily available and easy to work with. I just don't see the benefit of using a 3D printed body tube beyond being able to say I made an entirely 3D printed rocket. I know I can do it but it just seems like a waste of time to me personally seeing as how there are much better alternatives out there.

There are and there are not. Someone up in Canada was mentioning in another thread of there own printing body tubes, why? Because for the smaller size that you cant get with mailing tubes, that getting estes, etc. body tubes was quite expensive.

In the States? Sure, body tubes are cheap.

But then again, just because you can use an existing material doesn't mean that people aren't interested in exploring other alternatives. FG itself, nor BlueTube, etc, etc. wouldn't be available if people had just say 'no, for hobby rockets even big ones cardboard is only thing'.

Oh I can print body tubes that are colorized and no painting required. I can also just print a single layer sleeve too.

 

[thzero]

Or buy tubing. Standard Estes sizes are super cheap compared to any other aspect of this hobby.

Again, depends on where you are.
And some times... its just because you can.

 

[r-dub]

I've built countless kits from "standard materials", etc. - and I'll certainly build more in the future. I'm about to dig into my first full fiberglass build in the next month or so. My experimentation into 3D printed rockets is exactly that - experimentation! I love the challenge of doing something different and new, and I really enjoy the design and simulation process involved in 3D printing my own rockets. Anyone can make a rocket from cardboard tube and some wood fins. But I challenge anyone to CAD up a rocket to be 3D printed and fly reliably, safely and efficiently flight after flight!

Since my original post, I've designed and flown several 3D printed designs - all of them quite successful in their own right! Since that first little 3FNC in my original post, I've printed a 3-cluster (18mm motor) PETG rocket standing over a metre tall. Next was a D/E powered carbon fibre filled PETG rocket that has an awesomely slow liftoff.

On my latest build, I decided to really challenge myself - a 3D printed, minimum diameter rocket designed to hit Mach 1. Also made from CF filled PETG, standing 800mm tall, this rocket took a G125 motor to do the Mach attempt. It sim'd out to Mach 1.04 in a "conservative" Open Rocket sim. I first flew it on lower power motors to prove it out, and just recently flew on the G125. The flight was perfect- straight up and completely out of sight in the blink of an eye. I just barely saw the parachute deploy at 1000m, but lost the rocket in the glare of the sun, and never saw it again!

For the record, that first little rocket in my original post is still flying strong after dozens of flights, including a few hard landings after frozen parachutes didn't deploy. PLA is tough if you know how to work with it