Jet Freak

[sooner.boomer]

Has anyone built a (full size) Jet Freak? I built one last year, and have only recently been trying to get it trimmed to fly. The dang thing is too nose heavy! It's built exactly to plans. I've tried balsa and plastic nosecones, but no joy. I even tried making a "staple" out of solid-core solder and crimping it on the rudder. If I can't get something worked out, I may try to add on some pop-up trim tabs to the rear end of the wings (which will add so much weight it will glide like a rock - problem solved!).

Plans: Jet-Freak.pdf

[mwtoelle]

Has anyone built a (full size) Jet Freak? I built one last year, and have only recently been trying to get it trimmed to fly. The dang thing is too nose heavy! It's built exactly to plans. I've tried balsa and plastic nosecones, but no joy. I even tried making a "staple" out of solid-core solder and crimping it on the rudder. If I can't get something worked out, I may try to add on some pop-up trim tabs to the rear end of the wings (which will add so much weight it will glide like a rock - problem solved!).

In my experience, a front-motor boost-glider with a fixed pod is going to be nose heavy before adding any trim weight. Both of the Estes Falcons (K-13) that I built needed extra weight on the tail to get a good glide. I have found that really small gliders are a bit more difficult to trim properly. Something as small as the Jet Freak should probably be flown in calm wind conditions. Good luck finding these conditions in Oklahoma.

[MarkII]

Add trim weight to the lower rear corner of the rudder-like tail. In this photo of my micro-scaled Jet Freak, you can see where I added the trim weight. This location gives you the most "leverage" to counterbalance the weight in the nose.

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[rokitflite]

Upscale it, and radio control it. That is my new solution to the problem... FORCE it to behave right . This design looks good and simple enough that its worth a try! A BT-60 motor pod would be nice

[AstronMike]

I built a flew something very similar to this about 20yrs ago, and had the issue of getting it decently trimmed. Add a *little* weight to the nose, no, now the tail, etc. Blah!

It flew well enough, but only on a dead calm day, as the first little disturbance caused it to start spiraling in. It's very difficult to get a straight delta planformed glider to be reliably trimmable unless you 'make something occur' to said wing. That Jet Freak doesn't appear to use any such mechanisms.

As Rocketflite alluded to, adding elevon tabs would make it MUCH easier to trim, but then you've also added complexity - how to make those flat for boost and up whatever amount for glide. Another idea is to bend the very tips of the wings up *very* slightly, as in barely noticable. Just enough to give you a 'trim envelope', and not enough to throw off the boost.

In this instance, slightly warped balsa may not be so bad for the wings, as that can also act as 'preset decalage'. Since I'm assuming yours is already built, and with straight 'stuff', you could just add *tiny* tape based trim flaps. Micro elevons, in other words, and use the minimum amount you can get away with.

It doesn't matter how well something boosts if it doesn't glide, and it doesn't matter how well something glides if it doesn't boost.

Might have to make that BT60 upscale with Readiboard after all, and use a nice warpy piece.

[rokitflite]

10 months later, RC upscale is under construction

[rokitflite]

Done! I love it so much I wanna do a LARGER one!