Oh, Chute!

[JimJarvis50]

In my 2021 NARCON video, I talk about a method I use to get reliable opening of the main parachute. The problem I'm trying to solve is how to keep the chute from tangling in rockets with heavy payload sections, such as the Tarleton State SLI rocket in the attached video. These payload sectgions tend to point downward and it's easy for the chute to get tangled.

The method I use consists of a piston with two long harnesses coming from it. One harness goes to the payload/cone section and the other goes to the deployment bag and pilot chute. The main is retained within the deployment bag until the pilot chute carries it up above the other rocket parts. Then, the main is pulled out in an orgained, vertical deployment. I don't often get a nice video of it, but we got one for this flight.

Jim

 

[Handeman]

That looks very much like what I am doing with my L3.

I have a pilot chute attached to the nose cone that pulls the d-bag out of the payload. The shroud lines are pulled out first, then the bag comes off the main, allowing it to inflate.



The only thing I would try to adjust on your flight is that fincan being so far above the payload. The main seems to open way before the fincan hits the end of the shock cord causing a large shock to the system.

Is there any way to balance the load on the drogue so the fin can isn't so far above the payload when the main is deployed? Would having the drogue close to the payload work better? Shorter shock cord? Just brain storming for possible improvements to an already nice process.

 

[JimJarvis50]

That looks very much like what I am doing with my L3.

I have a pilot chute attached to the nose cone that pulls the d-bag out of the payload. The shroud lines are pulled out first, then the bag comes off the main, allowing it to inflate.



The only thing I would try to adjust on your flight is that fincan being so far above the payload. The main seems to open way before the fincan hits the end of the shock cord causing a large shock to the system.

Is there any way to balance the load on the drogue so the fin can isn't so far above the payload when the main is deployed? Would having the drogue close to the payload work better? Shorter shock cord? Just brain storming for possible improvements to an already nice process.

The team used one of the 3-loop OneBadHawk harnesses. It's a 30' harness, but the third loop is only a few feet away from the end of the harness. I'm not a fan of that (I like 1/3, 2/3), so the fin can stays high. I suppose putting the drogue closer to the payload might be better for that harness, but the thing to do is to use a different harness. When I get 3-loop harnesses, I have Teddy put the loop where I want it.

Jim