A fully operational Water Rocket Derby Launching System

[bugwubber]

Was cold and very windy today so no launches. Instead spent time making 4 drawers for the launcher to keep all the launcher parts, stakes, ropes etc in.
1/2" caps make great drawer pulls.

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[bugwubber]

Your observation about the amount of water impacting the launch speed is very interesting. We've never seen an experiment that proved it conclusively until now. That's very interesting. Is there a way to repeat the test with the same water volume in identical bottles only with weights added to the top (used water filled bottles). The repeat test would show if it is the weight of the water that slows down the launches, or if you are seeing an effect of the smaller air volume depleting the energy because it expands in a shorter time.

Time to invest in a launch journal :-). And somewhere besides the front yard to launch...

[ptx]

Nice idea to keep things tidy

[bugwubber]

Did some further testing today, this time hooked up to the house water supply. The water loading behavior was consistent with what we saw using the water tower, just higher pressure. Larger volume rockets filled faster, and to higher level than smaller volume. Rockets with similar volumes filled to just about the same level.

I can't say the fill volume was a constant % yet. I'll need to do some carefull measurements later to determine that.

As for launch speed, here are two videos that confirm it is total mass, not air volume that determines launch speed for a constant PSI. I moved the rockets around so launch tube position could be ruled out as a contributing factor. The heaviest 4liter rocket has the black tape bands. The lightest 4 liter has the green bottle on top. The smaller rockets are 1.5 liter bottles.

[youtube][/youtube]

[youtube][/youtube]

~Bugwubber

[bugwubber]

Here's a "walk through" video of the WRD Launcher.

[youtube][/youtube]

Thanks,

Bugwubber

[U.S. Water Rockets1]

Here's a "walk through" video of the WRD Launcher.

[youtube][/youtube]

Thanks,

Bugwubber

That snow isn't fresh is it???

[bugwubber]

Here's a "walk through" video of the WRD Launcher.


Thanks,

Bugwubber

That snow isn't fresh is it???

Ha! No although I did hear of snow falling today north of here. I've heard many lakes still have a fair amount of ice.

[ptx]

A lot of work there but with a very nice result.
Probably you can even try a rocket powered sledge.

[bugwubber]

A lot of work there but with a very nice result.
Probably you can even try a rocket powered sledge.

Thanks!
Kinda funny, didn't seem like work at all.

For horizontal, I'm kicking around pumpkin races. Maybe have all the kids bring their jack-o-lanterns and mount them on something like a skate board with a bottle stuck on the back end.