Ejection charge

[Scott Nokes]

Hello all

When the summr comes, I will be doing my level 1 with my Loc hitch.
I will use the ejection charge at the front of the motor. However, just to be sure if the right amount, I'd like to do a couple tests.
Would it be ok to put the BP in the ejection charge well of my 38/240 case and tape over the end like the little disc that comes with the Aerotech motors?
Also how much securing down does it take to stop the rocket moving on the ground and damaging the fins or something

Thanks

 

[dr wogz]

do you mean a full burn of the motor to test the ejection charge? tape is typically used to seal up the charge well.

There are calculators to determine the proper amount of BP to use for the airframe.

Also, this can be practiced in flights prior to your L1. All my 29mm 'G' motors require me to measure out some BP into the charge well.

What is a 'Hitch'? not familiar with that one..

https://rocketrycalculator.com/rocketry-calculator/bp-estimator/

 

[Scott Nokes]

do you mean a full burn of the motor to test the ejection charge? tape is typically used to seal up the charge well.

There are calculators to determine the proper amount of BP to use for the airframe.

Also, this can be practiced in flights prior to your L1. All my 29mm 'G' motors require me to measure out some BP into the charge well.

What is a 'Hitch'? not familiar with that one..

https://rocketrycalculator.com/rocketry-calculator/bp-estimator/

Sorry Dr W.
I meant it to say LOC Hi Tech 45.

So can I put the BP in the charge well and ground test just the ejection to make sure I'm not over pressurizing it or under pressurizing it.

 

[rharshberger]

Sorry Dr W.
I meant it to say LOC Hi Tech 45.

So can I put the BP in the charge well and ground test just the ejection to make sure I'm not over pressurizing it or under pressurizing it.

Plug the flash hole with a bit of tape to keep the powder from falling out or if the ematch wire will fit through the flash hole you can do that. Just need to make sure the powder doesn't fall out of the flash hole, seal the forward end like normal. I assume you were not loading the fuel grains in the motor for testing.

 

[David Schwantz]

I always set my rocket in a cradle made of PVC. I have always thought it should recoil as in flight. For the most part the fin can should not move to much unless you put 30 grams of BP in her . I have also wrapped the parts in bubble wrap to protect the paint job.
Put BP in charge well as Rich states, ematch on top of the bp, tape over to hold all in place and then run your wires out the vent hole. Assemble rocket as flight ready, touch wires to battery.

 

[Scott Nokes]

Plug the flash hole with a bit of tape to keep the powder from falling out or if the ematch wire will fit through the flash hole you can do that. Just need to make sure the powder doesn't fall out of the flash hole, seal the forward end like normal. I assume you were not loading the fuel grains in the motor for testing.

That's correct, just wanting to get the ejection sized correct

 

[rharshberger]

That's correct, just wanting to get the ejection sized correct

I have done it the way I described several times running the ematch through either the forward closures small powder touch hole or through the lower payload bays vent hole as David suggested....just depends on how long your ematch wires are.