model rocketry question

[btp2k2]

how much of that toilet paper stuff do you really need to cram in the body to avoid burning the chute when the nose pops off for decent?

[Breaker]

Hey btp2k2,

Back in my days of model rocketry I can remember using about 3 of those 'toilet paper' like sheets of wading. Of course it all depends on the size of the body tube of your rocket; larger diameter tubes will require more wading. A good rule of thumb is to use enough wading to create one inch of 'blockage' (for lack of a better term) in the tube (enough that you can't see light passing through the body). Also, the wading shouldn't be packed tightly, it should lightly crumpled and slipped into the body tube. Fight the urge to push it all the way down on top of the engine - it only has to go far enough so that the parachute can fit in and the nose-cone will install.  The only purpose of the wading is to protect the parachute when the ejection charge blows so you don't need a ton of it. If you're lucky enough to recover the wading after the launch it should re-usable (that's the sign of using a perfect amount) - assuming the parachute is in good shape as well

Hope that helps.

Breaker.

[SithMaster]

wait your using toliet paper like stuff to create blockage?

[Breaker]

Hey SithMaster,

The description is accurate. I remember recovery wading being almost the exact size and consistency as toilet paper (okay, it was thicker); but it was treated  to be fire resistant.

Breaker.

[Tahnok]

Allow me to make this completely clear. Do not use toilet paper! I'm not saying that you were suggesting to use toilet paper. I'm just making absolutely sure that someone reading this realizes that, while they may look the same, they are not the same and cannot be substituted. Trust me, I've seen people try.

Also, I wouldn't try to use wadding over again. It may be possible, but not a real good idea. Don't spend money on the rocket and then cheap out on a part that's essential to recovery.

BTW, I find a good rule of thumb is to have at least a diameter thickness of wadding in it, no less than 1" though. Not so tight that it will prevent the chute from coming out, but tight enough that the ejection charge won't singe anything.

[TOK]

I read it was OK to use toilet paper, as long as you soaked it in gasoline first as a safety precaution.

[werejag]

hehehehe

fire

[Bones]

Little late here but......

As an alternative to wadding you can install a baffle. These are available for a range of standard BT sizes and will only cost a few bucks.

Once a baffle is installed you will no longer have to use wadding in your rockets. I hear they do wear out over time but their life can be extended by applying an epoxy coating to the surface that comes in contact with the ejection particles and gases.

There are a few different manufacturers but I prefer the fliskits.com range because he offers outstanding support to the rocket community.

[Havok]

Thanks for the tip Bones - I've built a bunch of rockets, and haven't heard of this before. Should save a bit of money...