Build Thread: 7 cell parasail w/ RC control

I got a test flight on Sunday. The fight was to 1312 ft. It looked like things deployed before the rocket reached apogee. The two solid state switches were tested in series and seemed to work right, but when I pulled the right lever down on the radio, that's when it seemed to deploy. I never turned on the switch for the other channel. The switch and lever both should have to be active to fire the charge. Back to testing and redesign on that.

The chute deployed correctly. I was able to steer it. It didn't work as well as I expected, I could only turn it one way. It was as if the right channel wasn't working and it was stuck in the neutral/middle position. I could only get it to turn one way by backing off the left channel. I had to keep the left channel near the center to keep the chute going straight. Because the back edges were down there wasn't as much forward speed as I would have liked. I'm also thinking the angle may need to be adjusted to give it a little more downward angle and more forward speed.

Somehow, the pilot chute didn't stay connected to the line on the top of the chute, the pilot chute and the d-bag went off over hill and dale. It might still be floating for all I know. Another d-bag is next on the list.

It took five flights, but I was able to fly the chute. Some more engineering and testing and I think It will be working pretty well.

The same idea had come into my head a short while back. Now I am wondering if it should just stay there for a bit. (Or not, because historically other people's struggles have not really been much deterrent.

1tree said:

The same idea had come into my head a short while back. Now I am wondering if it should just stay there for a bit. (Or not, because historically other people's struggles have not really been much deterrent.

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If you want to try, go for it. I'll tell you, I put all the RC stuff inside a 4" coupler. It has worked OK. Getting the parachute to deploy correctly has been the hardest part. There are lots of resources that will tell you how to fold and pack a parachute for skydiving. Unfortunately, that is to pack into a flat rectangular pack but for a rocket, you need a long round pack. Nothing out there to help with that.

If you do decide to build it, let me know how it goes. I'm not overly satisfied with my servo set up and how it steers. I also think I need more down angle on the chute as it doesn't seem to have enough forward speed.

I am seriously looking at the idea. My big problem is that the best info on the parachute has been a series of YouTube videos. I am still looking for a template that I could print out, blow up and use. Perhaps I expect too much.

Anyway, I have been scrambling, trying to figure out just how big a rocket would be needed to house the servos. From what I have found so far, I could possibly get away with a single servo, though that would not allow me to brake and two is norm. Also, wasn't sure how realistic sizing the rocket to a commercially made chute would be. I am sure, it could be done, but not really what I want to do.

At any rate, I figure a rocket could well make the Christmas wish list. And it would be pretty cool to extend the fun to flying it back down after the launch. And I have serious doubts I could take up RC parachuting while not annoying the wife without tying it to the rockets.

1tree said:

I am seriously looking at the idea. My big problem is that the best info on the parachute has been a series of YouTube videos. I am still looking for a template that I could print out, blow up and use. Perhaps I expect too much.

Anyway, I have been scrambling, trying to figure out just how big a rocket would be needed to house the servos. From what I have found so far, I could possibly get away with a single servo, though that would not allow me to brake and two is norm. Also, wasn't sure how realistic sizing the rocket to a commercially made chute would be. I am sure, it could be done, but not really what I want to do.

At any rate, I figure a rocket could well make the Christmas wish list. And it would be pretty cool to extend the fun to flying it back down after the launch. And I have serious doubts I could take up RC parachuting while not annoying the wife without tying it to the rockets.

Click to expand...

I also had a hard time finding a pattern. I did find a set of written instructions on how to make the chute be they were pulled off the site years ago. There are sites that will sell you a chute, but they won't tell you how to make one.

As for size, I looked at man-rated chute loading data. A beginners chute is rated at about 0.5 lbs per square foot of canopy. An expert chute was rated at ~2 lbs per square foot. My 4" rocket I use the chute with comes in at about 10 lbs so I made my chute about 20 square feet.

As for the size of the rocket, I found 4" was good because it allowed enough room for the servos and the chute. You might be able to get everything into a smaller rocket if you use a "winch" servo like they use for RC sailboats. The hardest part is getting enough "throw" on the steering lines. A 5" or larger rocket would definitely be easier to get everything into.