stick lengths and position for 2 and 3 stage rockets

[leedrill]

im wondering if anyone can give me anyinfo from experience on attaching sticks to 3lb coreburner and endburner in 2 or 3 stage configuration im starting to confuse my self with ideas for the first two to break away. what kind of extra length id need to make my sticks please anyone with experience fill me in on some simple ideas that work

[psyco_1322]

The stick just gets attached to the top motor, not any of the others. You might have to make a stand off for the stick so it doesn't hit the other stages below. You will have to make some short sections of tube to couple the motors together. They just need to be tight enough the motors don't fall apart when its standing still, when they are burning, the motors will be pressing themselves together, so it's not an in flight issue.

 

I might have a pic, I'll look and post one if I can find something later.

Edited March 21, 2013 by psyco_1322

[leedrill]

cheers a pic would help i think but sounds easy enough if i get one made before you get back to me ill let you know how it goes

should i be making the stick longer though

Edited March 22, 2013 by leedrill

[dagabu]

A very novel idea is to attach three sticks to the upper stage all at 120° to each other, two just need to long enough to hold the other stages. This allows for tight fitting stages and balance with three sticks.

[WonderBoy]

I use a method similar to what Dag described, but I use 4 sticks. If I am making a multi-stage rocket, it is generally to lift a hefty payload, so I use 2 long sticks, then 2 short ones just to hold the motor in place. I don't like using couplers because it can more easily over pressurize the upper-stage. As I see it, the coupler lengthens the time that the upper-stage is "under pressure", like a bullet in a gun. The single wrap of tape on the booster stage in this photo is unnecessary.

 

 

 

WB

[leedrill]

thanks wb i like this approach i will give it a go looks like the easiest and would be very successful if done right do you just black match the two motors together and i might even still run the single wrap just using the opposite side of the tape as i assume you have it there just to hold the booster while transporting

[dagabu]

I use a method similar to what Dag described, but I use 4 sticks. If I am making a multi-stage rocket, it is generally to lift a hefty payload, so I use 2 long sticks, then 2 short ones just to hold the motor in place. I don't like using couplers because it can more easily over pressurize the upper-stage. As I see it, the coupler lengthens the time that the upper-stage is "under pressure", like a bullet in a gun. The single wrap of tape on the booster stage in this photo is unnecessary.

 

 

 

WB

 

Nice! I like that idea even more!

[psyco_1322]

thanks wb i like this approach i will give it a go looks like the easiest and would be very successful if done right do you just black match the two motors together and i might even still run the single wrap just using the opposite side of the tape as i assume you have it there just to hold the booster while transporting

 

You should really not need to do any "fusing" to the second stage. Maybe a little bit of roughing to the end of the fuel grain on the booster. When the engine burns out, there should be enough fire there to flash up and light the next stage. At most, you could put a pinch of powder there to add extra fire. To much ignition might try to light the entire core and might cause a CATO.

 

When I use couplers, they are attached to the lower stage, the one braking away from the rocket.