Need help with ground testing

[JHydrazine]

Hello Everyone,

I just completed a build of a 4" BSD Little John set up for dual deploy.
I am employing an RRC2 altimeter with Newton's 3rd ejection canisters using 0.5gm of ffff powder for the drogue event and 1gm for the main (starting points subject to change with testing results).
I am looking for methods used for ground testing the setup as this is my first attempt at dual deployment. I seem to recall past threads/video of testing methods (rocket horizontal with a vacuum source at the ebay vent hole).
Questions:
1) I have drilled 3 ebay vent holes and if the vacuum method is used, do I need to seal 2 holes and use the last for the test?
2) After removing the vacuum source, I assume the drogue charge will be set off immediatly ( simulating apogee) and then the main ( the alt is set for 500ft)
Is this what I should expect?
Any input is greatly appreciated.
Thank you

 

[blackjack2564]

I have the same rocket and same alt.
I broke the test into 2 phases.

1 the RRC2 has a self test mode. rather than using live charges, you can use mini xmas lights if you have them.
do this test outside of rocket. Hook up either, if I remember correctly toggle the #2 switch immediately after power on [check your manual] and the self test mode activates. First lighting or firing the apogee event then the main.

Once I established that part of the unit functioned , I [using the lights] slid the unit into a paper towel tube, place hand over one end and sucked a vacuum from the other end . Standing in front of a mirror just dropped my hand from the open end and watched the lights blink.

Now I know that the sensor works and the firing mechanism also.

2. I load up the rocket exactly as in flight. complete with motor in tube, shear pins, shock cord etc.etc. ,taping the empty casing shut so the apogee charge can't vent out the back.
run the ejection charge leads out of the vent holes in the
e-bay[ rather than using the altimeter] Now you can fire the charges directly off a 9v battery. First the apogee , then the main. You will of course need extended leads for firing the charges to be safe. Hopefully all will work on first try, if not adjust charges till it does.

I use 20ft of TN for app and 20 for main. 1gr bp app and 1.5 for main [also 3 2-56 nlyon shrearpins in NC] Here's a link to my build and flight. My favorite load for this rocket is the J-275 in the 54mm 852 case. 5 flights on them have all been picture perfect and between 4200-4800ft depending on temp and wind.

https://www.rocketreviews.com/reviews/all/bsd_little_john.shtml

 

[JHydrazine]

Jim,

Thanks so much for the information.
By the way, your build detail on Rocket Reviews was used as a primary reference for my build.
Thanks again.

 

[blackjack2564]

By all means.... please post the results of your flight and what motor you used.

And don't forget the pictures. We all love pics here!!!!