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Water Rocket Bobsled Derby Race

Posted: Sun Mar 02, 2014 2:30 am
by bugwubber
The race will be held next weekend. Each Den from our pack will be given a bobsled platform with a 4liter water rocket installed. Dens will have to build a shell out of posterboard and duct tape.

We will then race them with reckless abandon!

I will post pics and video here.

Re: Water Rocket Bobsled Derby Race

Posted: Mon Mar 03, 2014 4:30 pm
by Spaceman Spiff
bugwubber wrote:The race will be held next weekend. Each Den from our pack will be given a bobsled platform with a 4liter water rocket installed. Dens will have to build a shell out of posterboard and duct tape.

We will then race them with reckless abandon!

I will post pics and video here.
That sounds like a lot of fun. You must have the best scouting events ever!

Re: Water Rocket Bobsled Derby Race

Posted: Mon Mar 03, 2014 7:35 pm
by Water Rocket Expert
Better than the ones I used to go to.

Re: Water Rocket Bobsled Derby Race

Posted: Wed Mar 05, 2014 9:01 am
by bugwubber
Thanks!

Here's the fence being transformed into runners
CAM00834.jpg

And here's 9 motors ready to go.
CAM00833.jpg

Re: Water Rocket Bobsled Derby Race

Posted: Sat Mar 08, 2014 11:45 pm
by bugwubber
This was an absolute blast!
CAM00853_8473.jpg
I'll upload video tomorrow after I get home. A GoPro went for a ride as well. Hopefully I can get that video.

Re: Water Rocket Bobsled Derby Race

Posted: Sun Mar 09, 2014 12:10 am
by U.S. Water Rockets1
bugwubber wrote:This was an absolute blast!
CAM00853_8473.jpg
I'll upload video tomorrow after I get home. A GoPro went for a ride as well. Hopefully I can get that video.

Where did you get your own Pepsi Machine from?

Re: Water Rocket Bobsled Derby Race

Posted: Sun Mar 09, 2014 1:18 pm
by bugwubber
U.S. Water Rockets1 wrote:
bugwubber wrote:This was an absolute blast!
CAM00853_8473.jpg
I'll upload video tomorrow after I get home. A GoPro went for a ride as well. Hopefully I can get that video.

Where did you get your own Pepsi Machine from?
It came with the BSA camp. First thing we thought was- would it keep the drinks warm enough? But alas it was off.

Re: Water Rocket Bobsled Derby Race

Posted: Mon Mar 10, 2014 8:44 am
by bugwubber
So we had a bit of good fortune we were able to take advantage of. The parking lots and roads at the camp had just been plowed to a smooth hard snow pack surface on Friday. Even with snow tires and 4-wheel drive, it was slick driving. Perfect for the bobsleds!

Each rank was given an identical bobsled chassis and powertrain on site.

They then made a shell for their sleds out of posterboard, foam core posterboard, and duct tape.
CAM00846.jpg
We added 2" ABS plastic ice blades to the back ends of the runners to help with directional stability on the slick hard surface after they completed the shells.

It was an absolute riot.
[youtube][/youtube]

Onboard Rear Facing Camera
[youtube][/youtube]

Re: Water Rocket Bobsled Derby Race

Posted: Tue Jun 21, 2016 7:05 am
by addstogether2
Hi that bob sled idea is great. I am also a Cub Scout Leader here in Melbourne Australia and we have at least two water rocket nights a year.
Not much snow though.

I built a quad launcher for our cub pack as well loosely based on your original launcher.

Re: Water Rocket Bobsled Derby Race

Posted: Tue Jun 21, 2016 11:52 am
by bugwubber
addstogether2 wrote:Hi that bob sled idea is great. I am also a Cub Scout Leader here in Melbourne Australia and we have at least two water rocket nights a year.
Not much snow though.

I built a quad launcher for our cub pack as well loosely based on your original launcher.
Thanks! The origin of the bobsled derby idea was actually a wheeled pumkin chariot derby. Unfortunately October is pretty well packed so that idea never got out of my head.

Would love to see pics or video if you have any :-)

Re: Water Rocket Bobsled Derby Race

Posted: Wed Jun 22, 2016 5:43 am
by addstogether2
Here are the original pics of the quad launcher.

It had to be modified as the dads helping were using the launch tubes as a lever to tilt over the head to put the rockets on.

As you can see it is two way hinged, 1 to tilt over to load rockets and the other to launch.

All pegged down for safety.

I don't have photos of launch on my phone however will upload when I get a chance.
Al

Re: Water Rocket Bobsled Derby Race

Posted: Wed Jun 22, 2016 2:09 pm
by bugwubber
addstogether2 wrote:Here are the original pics of the quad launcher.

It had to be modified as the dads helping were using the launch tubes as a lever to tilt over the head to put the rockets on.

As you can see it is two way hinged, 1 to tilt over to load rockets and the other to launch.

All pegged down for safety.

I don't have photos of launch on my phone however will upload when I get a chance.
Al
Nice launcher!

I noticed when I had ours tilted horizontally and all the weight of the 5 rockets were off the launcher the high strength steel bar would bend enough at 100psi that the middle rocket would come off of the o-ring and vent. So, we launched the bobsleds at 75psi. I like the metal launch tubes and flex hoses you used. I think going back, for heavy Cubscout use they should really be metal and not PVC. I did manage to break a tube in the cold moving it around once.

One other thing we ran into in the launches was problems with rockets that were launched more than once. Had to keep a bucket of water nearby to rinse sand out of the rockets that came from previous landing. Had a couple of them really lock on to the pvc launcher tubes, to the point where we had to cut the rockets off.

Anyway, those issues aside, it was a lot of fun!

Re: Water Rocket Bobsled Derby Race

Posted: Sun Jun 26, 2016 9:13 pm
by addstogether
Yes the Cubs really do enjoy their rockets. We launch ours at the local high school who have a nice big oval and open area and let us launch there.
We have a standard weighted fall off nose cone and parachute system that we use a slip knot to attach to the rocket. It works OK most of the time as long as its not pushed down tight. I will post some pics of some of our launch days soon once I go through the archive.

Al

Re: Water Rocket Bobsled Derby Race

Posted: Sun Jun 26, 2016 9:45 pm
by addstogether
With the launcher we had to use non plastic components and hydro-static test it to well above the pressure we are ever going to use it at to comply with our safety standards and regulations here in cubs. The o rings have to be replaced each launch day due to the wear and tear like you also discussed.

Addstogether and Addstogether2 are both me the 2 is my work login.

I have been building and launching Water rockets for at least 10 years however only joined in 2010.

Re: Water Rocket Bobsled Derby Race

Posted: Wed Dec 06, 2017 8:29 am
by thampson
Great project :). For some extra fun see if you can an add RC control to the front runners . will make it fun for the drivers to steer them .. we did this with our water rocket car :)

enjoy

-todd-