What can you build with a Pringles can? A rocket that looks like a bomb!

When I first got my 3D printer I printed some parts for a Rear Eject Bomb Rocket MK II by Aslansmonkey I found on Thingiverse.  The design is supposed to eject the parachute from the rear of the rocket and calls for using a Pringles can as the body tube (with a diameter of 2.95" and length of 11.25").  I didn't have any Pringles handy at the time so I set it aside and moved on to other projects.  Recently, I decided to revisit that project and try to clear off some space on my bench.  I had a Pringles can (yes, honey, I ate most of them myself!) and decided to go ahead and try trimming off the metal edges and seeing what I could build.

I'd learned a lot about 3D printing since January, and reprinted some of the engine mounts and tail section using PETG for better heat resistance then layer everything out to see how to assemble it.

After trying different configurations I figured out how it's supposed to go together and started off glueing the inner engine mount.

The design calls for wrapping the main parachute (attached with Kevlar to the body of the bomb itself) around the top half of that inner engine mount and attaching a second small parachute (or streamer) to the nub that sticks down on the center ring (above) and wrapping that parachute around the lower half of the engine mount.  Upon the engine's ejection charge this inner tube should be pushed out the back, releasing both parachutes for separate recovery of the two parts.  At least, that's the theory...

I had the tail fin assembly with the inner body tube test fit (on the right, above) and attached that using JB Weld clear epoxy.  After connecting a long piece of Kevlar to the top engine mount and feeding it through the body (this will hold the main parachute to recover the "bomb" body after the engine mount ejects with its own streamer or small parachute) I glued two launch lugs to the Pringles can and glued the Pringles can onto the base.

I used a washer and nut to tie off the Kevlar so it wouldn't slip through the top engine block.

After the epoxy had hardened I decided to go ahead and paint the rocket (setting aside the internal engine mount).

I ran out of paint three quarters of the way through and will need to sand and repaint parts of the body but it's starting to look like a real bomb. I'll test spray paint some decals (the designer provided 3D printed stencils shaped to match the Pringles and nose cone contours) before repainting to decide whether that will work or if I should just print my own decals and use that.  The finished "bomb" is 20.5" tall and almost three inches wide.  At least this one looks interesting and is off my build pile!  Here's the test print taped up and after the stencil is removed:

This custom rocket plan came with instructions to use an E12-4 engine and a report by the designer that it flew to 450 feet.  I made an OpenRocket simulation, based upon my measured weights for the 3D printed parts, which predicts mine will fly 150 feet on a D12-3 and 354 feet on an E12-4.  I wasn't able to fully simulate the square tail section but accounted for the weight in this prediction.  Here's the summary and simulated rocket in flight.

It's joined the rest of my fleet (behind Miss Riley).