The Engineering Design Process ... With My Five Year Old Daughter (Pt. Three)

We had a short hiatus to start school but we did make some more progress this past month on the rockets! Following our disastrous first launch, (outlined in Part Two), we knew we needed some major improvements. My daughter identified several areas to improve and was especially focused on the launch pad and the fairings. In our trial launches, the launch pad failed to hold our rocket well and it toppled several times, while the fairings did not hold up to the stresses of launch (or water)!

The Launch Pad

After she saw a few examples online, she decided it would be best to attempt to build a PVC launch pad. We started with a simple H shaped base with a small hole to attach the air pump and it worked great on our tests (just bottles). Since the photo, we replaced the tape with glued end caps to improve pressurization but otherwise, she was very happy with the new "launch pad". A small black "o-ring" at the base of bottle insert helps maintain the pressure inside the bottle.

The Fairings

This is where it really started to get fun as we dove headfirst down a side path. Once my daughter identified what our fairings should look like, we talked about making them out of plastic because it would be waterproof and lightweight just like the soda bottle itself. So how can we make plastic fairings? It was time to dive into the world of 3D printing!

Everyone in manufacturing knows the processes and technologies used to make a product are almost always far more challenging and complex than the product itself, and rockets are no exception. Elon Musk says at SpaceX the robots used to build Falcon 9 are 100x more complex than the actual Falcon 9! Our exploration into 3D printing demonstrated that concept well as we learned about all the aspects required for success (and it's still a work in progress)!

We started with a basic design we found for free on Thingiverse and made some modifications to the model to suite our rockets. We also tinkered many times with various printer settings, filament settings, temperatures and speeds. We even had to re-level the beds a couple of times! All in all, after many failed attempts we ended up with a pretty slick fairing (pictured below).

Coming Next

Now that we had a basic fairing (it also has a base that attaches to the rocket) we were able to test the new rocket. The rocket itself worked alright so now its time to make some modifications so the fairing can house a parachute and open at the moment the rocket stops rising.

We also want to improve the pressurization of the rocket so we are going to print and test the gardena hose attachments we found on Thingiverse as well (and make the appropriate modifications to our launch pad). We hope to have a working rocket, parachute and improved pressurization system by the next post!