A couple of weeks ago we saw the episode of 'Ask This Old House' where they build 3 projects for kids - a garden, indoor putt-putt course and a water rocket. They've got an article on their site about how to build the rocket and some other family friendly projects.
The guy they had on the show to demonstrate how to build a rocket has his own website at http://www.sciencetoymaker.org, and you can also check out his original plan on how to build a water rocket. He's got step by step videos on what to do, a materials list and launching tips. That's where we went to get our plans.
After raiding a couple of recycling bins for 2 litre pop bottles, we headed out to Home Depot to pick up the PVC pipe needed for the rocket launcher. Unfortunately the one near me does not stock it. Next we tried Canadian Tire - Bingo. Well, almost. I didn't realize it at the time but I bought CPVC instead of PVC and the instructions specifically call for PVC. In the materials list which I had printed out and brought with me it says 'PVC--not CPVC!--plastic pipe', unfortunately I somehow missed that.
When it came time to put the launcher together, the CPVC has a smaller diameter than PVC and the bottle does not fit as well. To seal the bottle to the tube, you use a candle to heat and expand the tube. This turned out to be the most difficult part with the CPVC, I assume it is much easier with PVC which does not require as much expansion.
In any case I eventually got it to seal after wrecking a few feet of the CPVC, and wrapping the expanding section in teflon tape. I also had to cut down the outside of the tire valve to get it to fit within the CPVC cap and the hose clamp I had on hand to secure the cable ties was just big enough to squeeze over the ties.
After much fiddling around it is now working well. We've probably launched it 30-40 times and it's great fun. Both Lauren and Joshua love it and so have the other kids that have been over to see it. I'll probably build another one out of PVC as the bottle seal on the launcher leaks on me for every launch, but until then we'll be launching this one.
The guy they had on the show to demonstrate how to build a rocket has his own website at http://www.sciencetoymaker.org, and you can also check out his original plan on how to build a water rocket. He's got step by step videos on what to do, a materials list and launching tips. That's where we went to get our plans.
After raiding a couple of recycling bins for 2 litre pop bottles, we headed out to Home Depot to pick up the PVC pipe needed for the rocket launcher. Unfortunately the one near me does not stock it. Next we tried Canadian Tire - Bingo. Well, almost. I didn't realize it at the time but I bought CPVC instead of PVC and the instructions specifically call for PVC. In the materials list which I had printed out and brought with me it says 'PVC--not CPVC!--plastic pipe', unfortunately I somehow missed that.
When it came time to put the launcher together, the CPVC has a smaller diameter than PVC and the bottle does not fit as well. To seal the bottle to the tube, you use a candle to heat and expand the tube. This turned out to be the most difficult part with the CPVC, I assume it is much easier with PVC which does not require as much expansion.
In any case I eventually got it to seal after wrecking a few feet of the CPVC, and wrapping the expanding section in teflon tape. I also had to cut down the outside of the tire valve to get it to fit within the CPVC cap and the hose clamp I had on hand to secure the cable ties was just big enough to squeeze over the ties.
After much fiddling around it is now working well. We've probably launched it 30-40 times and it's great fun. Both Lauren and Joshua love it and so have the other kids that have been over to see it. I'll probably build another one out of PVC as the bottle seal on the launcher leaks on me for every launch, but until then we'll be launching this one.
Joshua drilling the end cap for the tire valve
Our first successful launch
Getting ready for the next launch
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