3D printing

[tmazanec1]

I did a Toastmasters speech on this new technology.
Does it have any application in amateur rocketry?

 

[tim cubbedge]

Lots of applications in rocketry & a handful of products already in production by a few vendors.
3D printed sleds, nose cones, centering rings, camera shrouds to name a few.

 

[tab28682]

I did a Toastmasters speech on this new technology.
Does it have any application in amateur rocketry?

Sure does. Quite a few people here in the forum are doing their own part printing. 3d printed parts of many kinds and even complete 3d printed rocket kits are available.

Do some searching here in the forum and you will get lots of results.

 

[djkingsley]

I print my own AV bay sleds, fin jigs, rocket stands, and motor mount jigs just to name a few, check out my https://www.thingiverse.com/Djkingsley/designs page to see some of my parts.

 

[Nytrunner]

Wasn't there an incident with a 3D printed rocket at NSL this year?

I think its a great prototyping tool. It just has its own quirks and design factors to incorporate (like z-axis lamination)

 

[jnelson]

AeroTech DMS motors now use 3D printed thrust rings.

 

[eggplant]

AeroTech DMS motors now use 3D printed thrust rings.

Is this correct? I haven't seen anyone else say this. It seems like a strange choice given the conditions at that end of a burning motor.

 

[djkingsley]

Wasn't there an incident with a 3D printed rocket at NSL this year?

I think its a great prototyping tool. It just has its own quirks and design factors to incorporate (like z-axis lamination)

Yes layer adhesion is very important, I am not a proponent of using 3D printed objects for structural parts of a HPR rocket. However there are many ways to use 3D printed parts in building a rocket, I do use 3D printed sleds in my AV-bays in HPR and nose cones of MPR rockets.

in my opinion PLA should never be used in a rocket, I have seen a lot of PLA go soft sitting on the pad on a hot summer day.

 

[ttabbal]

I have made and used AV bay parts, various jigs, grain cutting and coring guides, fin alignment guides. I could see making centering rings, nose cones, transitions, scale detail parts and probably lots of other things.

Use for rocket parts needs to be considered carefully. Layer lamination problems, heat resistance, and material strength. These are plastic parts, so in some cases you might need to reinforce them with fiberglass or similar. Any parts on flying rockets I plan on testing with low/mid power motors first.

My favorite plastic to print is PETG. It's stronger and more heat resistant than PLA, but easier to print than ABS. I keep meaning to try some of the high temp PLA, but it's still kind of pricey.

As for the thrust rings, that's on the Aerotech website. I believe they are ABS so they can take a fair amount of heat.

 

[OverTheTop]

I am in the process of building a Nike Apache and have made use of 3D printing for the NC (4"), payload bay transition (3"-4") and interfin spacers (scale detail and camera mounts) on the Apache. All the details are here on the build thread:
https://www.ausrocketry.com/forum/viewtopic.php?f=6&t=5019





I also tried to build the fins with a 3D printed isogrid core (bonded to CF skins) but I didn't have time to get the bonding right for the ABS. Went back to a G10 f/g core (CNC routed) for those fins.

The NC has had about six flights on my Velociraptor. No problems.



If the Melbourne weather manages to improve from its unseasonable unreasonableness it is currently showing the Apache will fly solo next weekend on an M840. I'll let you know how the transition goes! It has been designed well for flight, but I am concerned it may suffer "broken chalk syndrome" when it lands. Probably not, but possible.

 

[neil_w]

View attachment 304719

Two words for that picture: Awe. Some.

 

[djkingsley]

I bought a roll of the high temp PLA to try out and was not a big fan. PETG Is my preference for rocket parts also. I do have a roll of polycarbonate that should print at the top end of my current hotends capability, holding of testing it until the higher wattage E3D hotend gets installed.

 

[OverTheTop]

Many people shun the method for rocketry components. I think it is called skepticism and conservatism in a lot of cases.

It is a material like any other. It has specifications (assuming good process control ) so designs are still calculable. Z-axis strength needs to be figured in. Things have to be done differently than with other materials, and printing is not the only process needed for the parts usually. It is also slow. It is not suitable for all parts.

Learn about it, think about it, design it, build it in. That's what I have done.

 

[jnelson]

Is this correct? I haven't seen anyone else say this. It seems like a strange choice given the conditions at that end of a burning motor.

Yep, I have seen them myself. Apparently they've been tested quite extensively. All the 29-54mm motors have them (don't know about the larger ones). Looks like they're on the RCS site as well: https://www.rocketmotorparts.com/Thrust_Rings/cat1577810_2125751.aspx

 

[eggplant]

Yep, I have seen them myself. Apparently they've been tested quite extensively. All the 29-54mm motors have them (don't know about the larger ones). Looks like they're on the RCS site as well: https://www.rocketmotorparts.com/Thrust_Rings/cat1577810_2125751.aspx

Interesting. I have only flown one DMS motor and it used the old paper thrust ring.

 

[FredA]

I know of a great application.
I've used it myself.
Successfully used in a very high performance rocket (M powered minimum diameter) flown this year at Balls.
A game changer for one [critical] part of every rocket.

But not mine to talk about.....
It is my understanding that there is an upcoming article for Rockets Magazine.
Watch your future issues.

 

[Winston]

I am in the process of building a Nike Apache and have made use of 3D printing for the NC (4"), payload bay transition (3"-4") and interfin spacers (scale detail and camera mounts) on the Apache.

Nice!

 

[jderimig]

Like a previous post its all about the application, knowing your process and engineering.

I use PLA (!) ejection charge holders. 3 flights so far, no problems, 3g+ charges.

 

[BLKKROW]

3D printing has limitations just like a lot of other manufacturing process. However, if you know the limits of your printer and the material you will be surprised how useful 3D printing can be. I use it a lot for my rockets while building, flying and for recovery.

 

[cerving]

I've been wondering if anybody had tried that, apparently the temperature and pressure of the BP charge isn't enough to compromise the structural integrity of the wells. Good to know...

Like a previous post its all about the application, knowing your process and engineering.

I use PLA (!) ejection charge holders. 3 flights so far, no problems, 3g+ charges.

 

[Winston]

I've been wondering if anybody had tried that, apparently the temperature and pressure of the BP charge isn't enough to compromise the structural integrity of the wells. Good to know...

That is surprising. Short duration must be the reason.

 

[jderimig]

That is surprising. Short duration must be the reason.

In testing (on the ground) the piece was just barely warm after firing, not much heat gets transferred to the charge well.

 

[Delta-IV]

I use 3d printed parts in my RSR Kits that Apogee is currently selling. The plastic is ABS which is strong and somewhat light weight.

 

[Incongruent]

I use 3d printed parts in my RSR Kits that Apogee is currently selling. The plastic is ABS which is strong and somewhat light weight.

Oh good, it is ABS. If it's ABS you can sand the pieces so the dust fills the cracks then wipe the it with acetone to dissolve and solidify it smooth.

At least, that's what I heard. Maybe the parts end up too small or something.

 

[ttabbal]

ABS can be acetone smoothed easily. It also increases Z-layer bonding. It's often done using the vapor rather than the liquid directly. Another option that works for other plastic is epoxy coating. Or even fiberglassing depending on the shape and requirements.

Acetone processing is one reason to like ABS. It can be a pain to print, but once you get a process down it's not bad for most things.

 

[OverTheTop]

Acetone processing is one reason to like ABS.

I have not tried the acetone treatment yet.

I use cyanoacrylate glue for the surface finish. Sand, apply CA, sand, Apply CA, sand. Done. Sanding CA is not so bad, and less CA is used as the steps progress. I use Loctite 401.

 

[K'Tesh]

With the support of several others, I formed a team with Doug Bertelsen (and his crew) and now with the Boyces (Boyce Aerospace Hobbies). We're trying to create replacement parts for the original Cineroc, as well as parts that may allow a person to print one of their own (to use with either digital or film formats). Printed in black ABS, the results are very hard to tell from the real things after sealing the layers with acetone, then sanding down the ridges with 320, then 400 grit sandpaper.

With a little polishing, and proper application of the tape, it'd be even harder to tell one from the other.

 

[ttabbal]

Just thinking this thread should be bumped.. I made a crayon nose cone.. Pretty simple, still learning 3D CAD, but it was fun. Printed in ABS for 54mm tube.

 

[Cabernut]

I took an introductory course at my local library on how to use their MakerBot. Cool because I can now try 3D printing parts. What I'm cautious about is the fact that they only use PLA. I don't know if it's high-temp, just that the nozzle is set at 210C.

Question:
Considering I don't have a choice of another material, what kind of parts are best suited to PLA?

 

[GlenP]

Has anyone made a 3D printable model for the fin can for a Centuri Screaming Eagle?