Kestrel Ex

[Anonymous]

I hope this is the right forum for a build thread.

I was lucky enough to get a KestreL from John awhile back. I’ve had it for a few months and have read the instructions a few times and thought about what I want to do with it. The instructions are very good as is the quality of the kit. My goal is to send it higher then any other kestrel has gone. This is a pretty lofty goal considering some of the flights I’ve heard of so far. I mostly fly Ex and happen to have a 54mm motor that I made, that is 32.5″ long. I’ve flown this motor a few times and have gotten a tad over 29K at Balls 2006 with it.

At this point I don’t plan on any radical changes to the rocket other then shortening it some. It will still be dual deployment when shorter (AT 54/2560-2800) motors are used. I hope to begin construction in the next few days.

Tony

[John A. WilkeParticipant]

Tony, I can’t wait to see it… Knowing you, I’m guessing you’ll get a LOT of length out of the kit. You gonna do the chute in the nosecone again 😯 That is something I’ve never quite had the nerve to do, but you have done well with that technique.

Which propellant? When? I gotta be there!

[Anonymous]

I’ve done some work on the KestreL..but mostly more thinking and some sims. Below is a couple of my old 54mm min dia rockets and motor cases.

The top orange rocket was built in 2002 and flies to just under 20K with the AT K700. It’s dual deployment and has about 20 flights on it. The carbon fiber rocket was built in 2002 http://www.rocketryforumarchive.com/showthread.php?t=23810 and has gone just over 29K. It has about 8 flights on it. I’ll use the info I’ve gathered from these rockets to help ‘stream line’ my KestreL. The motors in the photo are an AT 54/2560, AT 54/2800 and an Ex case that I made.

In the below photo you can see the parts of the Kestrel lined up with the motor cases. My Ex case looks like it’s going to barely fit.

I won’t have much room for the electronics bay in the bottom part of the rocket..but I think it’s enough. The pencil is pointing at the bottome of the electronics bay. It’s in there about 1 caliber.

I think I’ll be able to get about 5 inches of length out of the rocket and I’ll be shortening the span of the fins by about 7/16 of an inch. I have some more sims to do before I start doing to much cutting.

Tony

[Warren B. MusselmanModerator]

Tony – I want to find out more about deploying a chute from the nose cone. I’ve never had a chance to examine a bird that does that and I have a 54mm MD DD bird designed to fly on an L that I’m trying to shorten a bit and deploying a chute from the nose seems to be the only option – aside from shortening the e-bay/coupler by going to one of Adrian’s altimeters. I think I want to do both to try to squeak every last inch out of the design.

Where does the charge go? In the nose?

Whatever I learn from this I want to apply to a 4″ MD project I’ve been fiddling with for a 5 or 6 grain 98mm motor I want to fly at BALLS.

By the way, we do have a couple forums for build threads – a general construction forum and a composites forum.

Warren

[Bruce R. Schaefer]

Where does the charge go? In the nose?

I’ve blown charges from the top but never with the chute in the nose. Do you blow from the bottom and tie the chute low on the harness so the nose clears leaving the chute out? This is good, guys.

[Anonymous]

Warren, A couple of things need to be done in order to be able to deploy the chute from the nose cone section. The interior of the nose cone must be smooth. If it’s not the chute or shock cord will hang up. I used a small flapping drum..1″..on the inside of thee KestreL’s nose cone to smooth things out. You also need to attach the shock cord to the tip of the nose cone. For the kestreL, I tied a knot in the end of the shock cord and then flared out the end and epoxied it into the tip of the nose cone. On my rockets I use a ‘zipper less design. So my nose cones get a section of body tube epoxied to them. I hope the below photo shows what I am talking about..

So, on the kestrel I cut the shoulder of the nose cone from it’s original 2″ to about .75″ I only need enough shoulder to epoxy it to the body tube. This nose cone/body tube section is what house the main and slides onto the electronics bay. The ematch is placed up in the tip of the nose cone. I’ve tried placing the ematch right on top of the electronics bay but all it does is blow you chute up into the nose cone..it does separate but your laundry is packed up it the tip of the nose cone. I’ve always had it work..when the ematch is place in the tip of the nose cone.

The chute is attached to the top of the eleectronics bay.

Tony

[Warren B. MusselmanModerator]

Thanks Tony,

That’s kinda what I envisioned except for the zipperless nosecone/forward airframe thing. I figured you’d have to attach the shock cord at the tip and put the charge in forward of the laundry in order to deploy properly. The zipperless thing definitely intrigues me and as soon as I read your post, have been fiddling around trying to figure out how to modify this bird.

My main and shock cord certainly won’t fit entirely within the nose, so my assumption is that the airframe glued up to the nose is sized to provide that space. I can probably lose 8″ or maybe even 10″ of length with this method. Now all I have to do is figure out how to fit a GPS into the e-bay so I can find the thing after it flies.

Warren

[John A. WilkeParticipant]

Only Tony could take a motor that is this long and STILL cut 5″ out of the rocket. His motor is 7.5″ longer than the Pro54 6G-XL that came with the kit… and he is cutting 5″ out of the rocket length. In other words, the KestreL has 12.5″ too much room (which is amazing!).

The most common question I got on the KestreL was “how am I going to fit all that stuff in the rocket???” I could shorten it… but not by 12.5″. That is just amazing!

Keep the pix coming, Tony – can’t wait to see it!

[greywolves]

Hi everyone,

Very nice Tony.

Question John, the tail cone that comes with the Kestrel, does it have motor retetion built in? locking snap ring?

Thanks

[John A. WilkeParticipant]

Question John, the tail cone that comes with the Kestrel, does it have motor retetion built in? locking snap ring?

Thanks

The CTI 54mm loads have an aft closure, which is a ring that is screwed onto the motor casing to keep the reload captive in the motor casing. The tailcone simply replaces that flat knurled ring with a smooth, tapered one. There is no motor retention with either the ring or the tailcone.

Those who have flown only 38mm CTI loads are probably confused – the 54mm and 29mm systems have a separate ring (or tailcone). The aft closure is part of the reload on 38mm loads. That is why you can buy rings and tailcones for 29mm and 54mm, but not 38mm.

Regardless of size – everything is threaded with 29 / 38 /54mm CTI loads. No snap rings.

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