Cheap DIY soda rocket for a kid’s birthday party [Free Plans]

Today, we build a cheap rocket for our kids
birthday party from a soda bottle. The web is full of cheap soda rocket plans. Most of them require PVC pipe, garden hose
adapters and a few hardware parts for 20 to 50 bucks – which is already quite cheap. As part of our kids birthday party we wanted
10 kids to build each their own rockets. So 20 bucks per rocket was still a bit too
much. We started to design our own even cheaper
version with 3D printed parts in FreeCAD with a total cost of less than 5 bucks for each
rocket. We printed the parts on the CR-10. For the parts to be water tight we increased
the flow at the 3d printer to 113%. The 3d model and a set of free plans are available
on our website. Link in the description. The first part of the rocket launcher is made
by cutting a piece of electrical conduit to a length of 35 cm. When we tested this step with our kids cutting
the pipe straight was actually quite challenging for them. So for the party we created this simple jig
where the conduit is clamped in place. The saw cut is then guided and results in
a straight end. This end is then closed with a 3D printed
cap. The cap is secured with a bit of superglue
and then genly tapped on the pipe with a few hammer blows. Superglue should not be handled by kids so
we took over this step after they prepared the pipe and the 3d printed parts. In the hole of the cap we glue a bike valve. To create a really tight seal we insert a
rubber seal in the 3d printed part. The other 3D printed parts are assembled with
screws and secured to the conduit with hotglue around 10 centimeters from the end with the
valve. If you don’t have 10 screaming kids around
you and have some patience epoxy or a glue used for PVC pipes creates a better seal but
in a hurry hot glue works just fine. For the rocket launcher we need 5 wooden scrap
pieces in total. All the dimensions can be found in the plans
on our website. For the largest piece the kids connect the
corners to find the center point of the board. Here they use an old hand drill with an auger
bit to bore a hole. They then nailed the larger piece on the two
smaller ones to create the stand. During the party we used a dap of hot glue
to hold the pieces in place and the kids can drive the nails home. Another scrap piece gets a center hole before
it is cut in half and two mounting holes are drilled in each part. The kids use these pieces to screw them into
the base and secure the conduit in an upright position. From a pure functional perspective the rocket
launcher is done and we could start launching soda bottles. But we don’t want to launch soda bottle
— we want to launch rockets. So we cut some pieces of craft foam on the
laser cutter so that the kids have fins, a cone and some decorative elements. If you don’t have a laser cutter you could
also use a water jet, a CNC or an exactor knife to cut the craft foam. The last thing missing is a remote trigger. At the moment you would have to hold the brackets
with your hand and would get wet during the launch. So we cut more scraps in shape on the bandsaw. This part can now be slit over the two brackets
and holds them tight while pressure is being build up in the bottle. With a piece of rope attached to it you can
pull the trigger and launch the rocket. When all the rockets are finished it’s launch
time. We fill the rockets half with water, then
build up some pressure with a bike pump and launch them. This was a super fun project to design the
rockets and build them with a bunch of kids. If you liked this video also check out some
of our other videos, don’t forget to subscribe to keep up with new videos and follow us on
Instagram for a look at future projects.

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