Estes Eagle Boost - two flights, two lost nose cones - help!

[jf_reinhard]

So I've flown my Eagle twice so far, once on an A8-3, the other flight on a B4-2. Both flights were great and it glided well. Unfortunately, on both flights, the nosecone on the rocket booster detached from the rip cord and I never found it. I was thinking maybe I had too much weight in the nose cone, but I don't know for sure. Since I didn't weigh the one square of clay from Estes that I put into the original nose cone, I had no way of knowing how much to use for the second nosecone, so I guesstimated. Maybe the knot came loose? I have no idea.

Any suggestions? I would really like to avoid having to buy more nose cones and expect to lose one with every flight.

Thanks,
Jim

 

[bcanino]

You mean from the pop pod, with the streamer?

Where did it detached from? Did the rubber band pull from the tube? Break? of untie from the nosecone? Can you tell?

I found the shock cord on the Eagle a bit too long for a B/G. ironic, for a Estes kit ( where they are usually way too short )

So I've flown my Eagle twice so far, once on an A8-3, the other flight on a B4-2. Both flights were great and it glided well. Unfortunately, on both flights, the nosecone on the rocket booster detached from the rip cord and I never found it. I was thinking maybe I had too much weight in the nose cone, but I don't know for sure. Since I didn't weigh the one square of clay from Estes that I put into the original nose cone, I had no way of knowing how much to use for the second nosecone, so I guesstimated. Maybe the knot came loose? I have no idea.

Any suggestions? I would really like to avoid having to buy more nose cones and expect to lose one with every flight.

Thanks,
Jim

 

[jf_reinhard]

yes, it was from the pop pod. It seems to have detached from the end of the shock cord. I know in both cases I tried a very strong knot.

 

[AKPilot]

Having seen a few people attempt to use the Eagle, I'd give you a sincere recommendation to forget about it and move on to an Edmonds glider. You're going to spend more time, effort, and money attempting to get the Eagle right than the pleasure of putting an Edmonds together and enjoying launch after launch.

Even if you get your issues with the Eagle sorted out, you're going to have other issues with the exhaust burning your empenage.

 

[chanstevens]

With the Eagle/pod, you've got a number of design-related isues stacked up against you:

1) Nose weight means greater energy involved at end of "stretch" that the shock cord has to be able to deal with, versus a regular cone.

2) Cheap/flimsy rubber, easy to break and prone to burning, especially given fairly small body tube which means very little wadding winds up being used

3) Boost glider designs favor shorter shock cords to prevent "Red Baron" effect of the glider getting caught in the shock cord trying to fly through it during deployment.

If you want to stick with something close to "stock", my recommendation would be to pick up about 4 feet of 125-150# Kevlar (Commonwealth, Flis, Semroc, BMS, etc.) and attach one end to a 20/5 centering ring, which you then insert from the forward end of the body tube as far back as you can get it, ideally against the front of the motor tube, using a dowel to drive it back there. Anchor the other end to the nose cone, though will probably need a little epoxy since it will break away the plastic eyelet, which means you can get rid of some of the nose weight. Prep with wadding as usual, but tie a bunch of slip knots in the Kevlar so that it packs up small/compact and eats up a lot of energy pulling open all those slip knots during deployment.

--Chan Stevens

 

[jf_reinhard]

AK and Chan,

Thanks for the recommendations. I think I'll buy some Kevlar, since it'll come in handy for a few other projects I'm working on. I'm almost done with my first Edmonds Aerospace build, a Deltie B, so that should be flying soon (today is the maiden flight of my Semroc Hawk). Only problem with that one is that Rob forgot to mention where I need to mark the fuselage to determine the CG. I'll send him an e-mail. Everything else is so far, so good.

The Eagle flies well. It's just that the booster nosecone and shock cord should've been better thought out by the Estes folks.

Jim