Model Rocket - B & C Engine Size
by NEATman, published
UPDATE - I've added "Rocket 2 - Payload.stl" It's the same size rocket, but with a payload section at the top. It also has a new lighter weight motor retention system, made from a cleverly bent large paper clip to keep the weight down. To assemble, straighten a large standard paper clip. Bend the "U" at one end, insert downward, from the nose cone end toward the tail end. Then bend the paperclip out sideways, and add the knee bend and loop at the end. It acts like a torsion spring to retain the rocket motor.
I tried unsuccessfully to properly print out the rockets that were here on thingiverse, so my son and I designed our own in solidworks. I think it was mostly due to learning the limitations of our TOM, and not a problem with the existing designs. You will notice that this is a "all at once" print, where you print the fins, tubes and nose cone all at the same time. There are connecting ribs between the parts so that the fin section will stabilize the other tall thin parts - you'll notice in one of the pictures that the print failed near the end when the tall skinny tubes were tilting around on the ABP conveyor belt.
It is currently just a simple design, but I hope to design a version that will include a mount for a "Spy-pen" camera to take video, and possibly one that will launch gliders when the nosecone is ejected, perhaps a propeller retrieval option for the nosecone - and any other wild ideas my 4 & 7 year olds come up with...
This was printed on a Thing-O-Matic, with a MK6 extruder, ABP (which made the first attempt unstable), the layer height is .35mm, feedrate of 30, and we used white ABS so the kids could color the sections with markers.
I have added a STL without the connecting ribs - just make sure you have a solid foundation - the incomplete print in the pictures was because the conveyor belt on my ABP was too "floppy" when the parts got that tall.
1.) Download file & create g-code
2.) Print parts
3.) Trim away connecting "webs" - these add stability during printing
4.) Assemble - glue sections together, leave nosecone a light friction fit (sand as needed) - Paint if desired - use 2 drywall screws for the original design in opposing holes to secure the motor - use one of the remaining holes for the guide rod on the launcher. For the newer design, bend a large paperclip as shown.
5.) Launch! (if you lose/break/destroy it, repeat steps 2-5)