Flis Cougar 660

Flis Cougar 660 - High Performance Competition Kit

I pulled some kits out to build over the July 4 (2010) holiday weekend. Among them was this Flis Cougar 660 . While it's not an old rocket per BAR classic standards, it is old in the sense that it's been hanging around my house for several years waiting to be built

I can't recall when I bought it. It might have been the NARAM in Evansville back in 2003, or it might have been at NARCON that same year down in Austin. But I got it because of its Estes-Sprint-competition looks.

While there are some finishing details I would do differently (if I had to do it over) I'm nonetheless quite pleased with the way the rocket turned out.

I also have been building an Astron Mark clone from Semroc, and decided to build both rockets with the same paint scheme.

The kit is very nice and includes a couple of really kewl extras:There's a 6" x 60" competition streamer and a very cleverly done pop lug, shown at right.

The included wire, under the orange sticker, is to be cut and formed to hook the lug between two fins aft and a tiny hole bored in the airframe forward.

The package included the components shown below. Besides the competition streamer, there's a more common crepe streamer for sport flying and a sheet of 1/64" birch ply for the fins along with three fin patterns. The competition streamer is the white object rolled up in the centering ring. As you can see, I chose the basic elliptical pattern. The fins are supposed to be mounted on the boat tail, but I moved them forward (and changed the root cut a little to maintain the sweep angle) to give it a more Sprint-like appearance. Furthermore, I opted to use 1/16" balsa in lieu of the competition ply.

The motor mount includes only one centering ring forward. And this is OK. I've seen competition flyers roll up vellum into egg lofter airframes and insert a motor tube and get it aligned without great difficulty. So I know it can be done. But since I'm not competing, I cut a longer motor tube and used two rings thus simplifying the motor mount build. Keep in mind, I'm re-engineering this to Doug's paradigm and not because it's in any way lacking. It is in fact a very well crafted competition bird IMO. Removing a little weight by eliminating a ring and shortening the motor tube are certainly good steps toward getting a competitive edge.

Since I opted to forgo the pop lug, I glued it in place after beveling the ends. Not sure if that really reduces drag, but it looks faster

Overall, the kit looks pretty nice. I like that style of nosecone. Again, it gives the bird a Sprint-like appearance.

Lastly, here's a close-up of the fins. I cut them from scrap 1/16" balsa I had on hand. As you can see, there's another vendor's logo on the rocket now. Thought Jim Flis would get a kick out of seeing that. (Sorry, Jim

)

I'm looking forward to flying this bird. The ½A3-4T and A3-4T motors are the likely woosh makers. I might even try it on a ¼A3-3T. I have a few A3-6T's which might work nicely, too.

And since I left out the motor block, I could even try one of the old A3-5m's I have.

I ran some sims and found the rocket to have marginal stability, less than 1 caliber with the motor loaded. On a long, skinny rocket, that's not very good. But these high performance designs, with their boat tails and unswept fins, tend to be that way. So adding some nose weight is common and to be expected.

5g of nose weight worked well in Rocksim. That, plus the weight of the chute and wadding, should make it plenty stable.

Here's how it was done. I drilled down about one inch into the base of the nosecone with a 5/16" bit, then bent some piano wire into a U, with some barbs formed on the tips at 90°.

I mixed up some epoxy, then added 5g of bird shot and poured the slurry into the opening with the piano wire in place. This gives me some nose weight and supplants the screw eye as well.

By the way, isn't RustOleum awesome?

I used Great Plane EZ-mask vinyl masking tape, and usually get outstanding results, but this time, for whatever reason, the paint wicked up under it and left some fuzz

I thought I had burnished the line adequately, but evidently not

The roundel turned out sweet.

The flag isn't nearly as tilted as it looks due to the camera perspective. But it is tilted a bit, unfortunately. I put it on, and kept studying it. I'd look at it, and it would look OK, then I'd look again, and it'd be tilted, then I'd look again, and it'd be OK. I finally convinced myself it was good and proceeded to dry the decal off. Then I realized it was indeed crooked

Oh, well. Stuff happens

I like the overall results anyway, and look forward to flying it soon.

On August 21, 2010, the Cougar 660 had its maiden flight on an A3-4T motor. It really needed a bit more delay, but that's not available. I do have some old A3-6T motors, but not sure I trust them.

I substituted a 1" x 27" streamer, and next time, I'll go with a bit more - it came down kinda fast on that one.

I recently had some decals made up. This one used a stencil font. I like the way it turned out. It adds that little extra that makes the rocket really stand out.

8-26-2010