Welcome to the Water Rocket Forum, sponsored by The Water Rocket Achievement World Record Association.

Since our founding in 2003, we've become the largest, most sophisticated and ground breaking group supporting you, the serious water rocket flyer! Whether you are a beginner or an expert, the WRA2 has something for everyone.

A water rocket is a type of model rocket using water as its reaction mass. The pressure vessel (the engine of the rocket) is constructed from thin plastic or other non metallic materials (usually a used plastic soft drink bottle) weighing 1,500 grams or less. The water is forced out by compressed air. It is an example of Newton's third law of motion.


Hello Everyone. It is that time of year again. Time to approve changes to the competition rules for the new year.

You Can vote at:
viewtopic.php?f=32&p=19486#p19486

Please take the time to vote. TH:

Tomy timer question

This forum is for non-members to ask questions about our competitions. Please check our FAQ page before you ask.
Post Reply
SaskAlex
WRA2 Member
WRA2 Member
Posts: 238
Joined: Tue Apr 07, 2009 2:36 pm

Tomy timer question

Post by SaskAlex » Sat Feb 23, 2013 4:06 pm

I'm planning on making another attempt at the class B record this summer, and it's brought up another question. I don't mean to be a stickler for the rules, I just want to be sure I do it legitmately.

The current Class B record holding rocket (Millennium by Bruce Berggren) used a tomy timer on the outside of the rocket. I also used one on the booster of my JP-2 rocket. However, that does mean you have metal pieces (the spring and the shaft of the timer) on the outside of the rocket. According to a strict interpretation of the rules, that's not allowed, and I think some teams do take pride in avoiding even small pieces of metal like these. However, maybe one could say that these are enclosed by the plastic timer case, or maybe they are so small not to even to count as "parts".

My current booster on my new rocket also has a tomy timer on the outside to deploy the booster's chute. I could change it to an airspeed flap without too much hassle. So what do people think, is a tomy timer on the outside of the rocket okay?

Alex



User avatar
WRA2
Site Admin
Site Admin
Posts: 1063
Joined: Sat Dec 30, 2006 11:30 pm

Re: Tomy timer question

Post by WRA2 » Sat Feb 23, 2013 5:48 pm

SaskAlex wrote:I'm planning on making another attempt at the class B record this summer, and it's brought up another question. I don't mean to be a stickler for the rules, I just want to be sure I do it legitmately.

The current Class B record holding rocket (Millennium by Bruce Berggren) used a tomy timer on the outside of the rocket. I also used one on the booster of my JP-2 rocket. However, that does mean you have metal pieces (the spring and the shaft of the timer) on the outside of the rocket. According to a strict interpretation of the rules, that's not allowed, and I think some teams do take pride in avoiding even small pieces of metal like these. However, maybe one could say that these are enclosed by the plastic timer case, or maybe they are so small not to even to count as "parts".

My current booster on my new rocket also has a tomy timer on the outside to deploy the booster's chute. I could change it to an airspeed flap without too much hassle. So what do people think, is a tomy timer on the outside of the rocket okay?

Alex
Hi Alex,

No problem, that is the purpose of the Q & A forum. The metal bits inside the tomy timer would be allowed if enclosed inside a "bay". If the rocket should explode. That "bay" would separate from the rocket as a large piece rather than as small high speed dense shrapnel that small metal pieces such as steel washers, nuts bolts and screws which could be thrown at the speed of a gunshot.

From the safety rules.

The payload container has to be constructed from strong non-metallic materials to completely enclose any metallic parts carried inside (batteries, electronics, and mechanical components).
The payload section is to be attached above all pressurized parts of the rocket and cannot contain any exposed metal parts.
The payload section must be separate from any pressurized portions of the rocket.

What probably is needed is a rewording of the part stating that the payload section has to be attached above the pressurized portion since multiple stage rockets would have staging mechanisms and booster deployment systems in other places on the rocket. Maybe instead, we add another line covering staging/ booster recovery modules and that would do the trick.

Thank you for the input, your insight and experience building multiple stage rockets is appreciated. TH:


Lisa Walker,
:WRA2: Forum Administrator. :WRA2:
:WRA2:The Water Rocket Achievement World Record Association :WRA2:

Post Reply