Sunday, 17 July 2011

New Inline Deployment System using Air Commands STII

Escape Water Rockets Inline Deployment System
I decided to go for something simple first just to get us back in the air as we've been a long time grounded. The pod is following the rough design that Air Command produced for an Inline Deployment System and for the electronics i have ditched my RC system and bought a couple of STII's (Thanks George) to control our system.

Deployment System:

Servo Timers:

One problem I've always had is making sure my Correx disks are in fact circular and the right size, and as i wanted most things to be as accurate as possible this time round i came up with a solution which I'd like to share.

I remembered i had a Dremel cutter down the shed with a cutting disk holder attachment so i thought why not attach the disk of Correx onto this disk holder spin it and sand it while it moves. So that's what i did.

I bought 2 of the STII's from Air Command and i intend to do something different with the second one although i am not 100% sure what that is yet, the expandability of the timers will help me think though.
I reinforced the area on the skin for the servo with another piece of PET glued to the outside skin.

Thank you for reading



  1. Looking good Doug. :) Good explanation video too of the deployment mechanism.

    When you put the first rubber band around the skewer stick and hooked it onto the motor, I noticed that the nosecone was just sitting there without deploying, as if the other side was caught on something. The nosecone should be set up so that either side coming off should deploy the parachute. Perhaps the spring wasn't strong enough, or the nosecone is a tight fit on the ring sitting on the base and was getting caught.

    Great suggestion in getting the corflute disks circular. I too have a problem in getting them cut out nicely. :) Do you just use regular sand paper?

    Good luck with the flights.

  2. Hey George,

    Since the video i have infact fixed the rubber band sticking problem turned out to be nothing more than them sticking on the servo arm a little and not leaving at the same time. I now put a little RC silicone shock oil on the servo arm, this keeps it slipery for the bands to come off easier.

    As for the sand paper i used a course P80 to start and moved to a p120 and p200 grit afterwards checking the fit as i went on, its by no means quick but it does the job right. :)

    Regeards Doug

  3. I appologise i just noticed which part of the video you meant with the sticking, ive just tryed to make it do that again and i cant :S must of just been somthing i did at the time, on the other hand i have changed the rubber bands so the loop that holds them to the cone doesnt go over the rim, it now comes stright out the side so that may have contributed