Pre-flight testing for Raven 3 dual deployment

The Rocketry Forum

Help Support The Rocketry Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

k3td

Well-Known Member
TRF Supporter
Joined
Dec 13, 2011
Messages
102
Reaction score
3
Location
Georgetown, TX
Here's my plan to test - this will be my first dual deployment flight. Would appreciate any feedback.

Already:
Using FIP program, calibrated the Raven and ran the Test Flight Simulation. Set main deployment for 480' for 3" MAC Performance Arcas kit.

Next:
1. Repeat test flight simulation with e-matches attached - safely away from black powder or anything flammable!
2. Calculate BP required for apogee and main charges based on tube volumes
3. Test apogee and main charges with e-matches/BP in rocket prepped as planned for launch but without Raven - using the 3.7v Li-Po battery that I will be using in the Raven

Thanks!
 
What's the apogee expected and why so low on the main? Are you testing to see if the Raven can fire your planned choice of ematch? That's reasonable.

Calculate the powder and ground test the deployment. The main is a bit more critical as you may have a tighter pack with a larger parachute.
Apogee not as critical as because one is usually pushing out a smaller chute. Ground test both though to be certain.

You using shearpins on the main chute bay? If not, you'll need to be careful that the force of a too aggressive apogee charge doesn't push the chute/nosecone out by momentum. Kurt
 
Be VERY careful when you try using the Raven-supplied LiPo to directly power your ematches. Any short of that little bugger, it will puff up and get wicked hot wicked quick. Don't ask me how I know this.

My suggestion:

Verify it will fire your igniters with the simulated flight option. Thereafter, merely use Christmas tree lights. To get these bright and white, you need much more power than an E-match--so if it will make these white, it'll fire your match, no problem.

I typically ground-test as prepped for flight, with a spent/dummy motor installed to seal up the MMT. If I have to run leads in to the av-bay to fire the igniter, so be it...



Later!

--Coop
 
I've found the EggTimer Rocketry Remote switch helpful to ground test charges. Just put it in place of your electronics on a temporary sled: https://www.eggtimerrocketry.com/page48.php

He also came out with a Wifi switch that could fire an ematch: https://www.eggtimerrocketry.com/page55.php

They're designed to turn-on one's electronics but I found the remote switch helpful for an MD rocket charge testing.

Now the EggTimer TRS can do ground testing from the control box which is very nice I used on a 38mm MD diameter DD which will unfurl the main with an
Archtype cutter. Kurt Savegnago
 
Thanks for the comments and suggestions!

First flight will be on a 3" MAC Performance Arcas kit and a Pro38 2 grain H motor, so I set the main deployment close to 500' instead of the default 700'.

Also, I'll use a 9 volt alkaline battery and manual switch to test the apogee and main deployment charge sizes instead of the 3.7v Li-Po battery.
 
If you have a tight launchsite, just make sure your chute is freshly packed and loose. Use a chute protector on the shockcord and don't use a bag for now. I have a tendency to fire the main up higher so the video camera has more
"hang time". I have more area to recover so I will pop the main at 1000 to 1200' for the video rockets and 700 to 900 for smaller rockets. If there is a deployment issue, the extra time sometimes helps.

Also, you'll find you can learn a lot by a downward facing camera on the upper bay to catch the apogee deployment
if you can do that later on.

I was nervous about a 3.7V lipo but a lot of folks us 'em and they fire the several kinds of ematches I have O.K.
I'd worry a bit if sitting out in cold weather for a long time and would charge them up after one flight.

Kurt Savegnago


Thanks for the comments and suggestions!

First flight will be on a 3" MAC Performance Arcas kit and a Pro38 2 grain H motor, so I set the main deployment close to 500' instead of the default 700'.


Also, I'll use a 9 volt alkaline battery and manual switch to test the apogee and main deployment charge sizes instead of the 3.7v Li-Po battery.
 
Thanks for the comments and suggestions!

First flight will be on a 3" MAC Performance Arcas kit and a Pro38 2 grain H motor, so I set the main deployment close to 500' instead of the default 700'.

Also, I'll use a 9 volt alkaline battery and manual switch to test the apogee and main deployment charge sizes instead of the 3.7v Li-Po battery.

For my 3" and 4" rockets with a single altimeter, I set the main deploy as low as I can. 400 ft on the HiAlt45 and 300 ft on the Stratologger. I've had lots of flights on those rockets and know how the mains deploy. Starting at 500 ft is probably a good thing with a new rocket, but if you get consistent deployments that will work lower, drop the main deploy.
 
Back
Top