Tantrum has flown!

[Dave_Sawatzky]

Put 2 flights on Tantrum this morning.

Seems to fly ok. I flew it pretty conservatively and haven't tried anything very radical yet. Seems to track well and flies predictably. Handles well on the ground during takeoff and landing with no tendancy to wander. Seems to have ample power on the vertical. Roll is pretty quick on high rates. Tried a few blenders which worked out fine. I think I may have overdone the right thrust (4.5 degrees... similar to Funtana) as it actually pulls a little to the right during the vertical lines. Rudder does not seem to be quite as effective as I had hoped. Waterfalls were pretty pathetic I'm afraid (Funtana never did them very well either). Aileron rolls are quite axial and rolling circles are easily done. Rolling harriers look ok too. Not too sure about knife edges yet. Definitely will require a fair bit of power to maintain level knife edge. Just a little bit of down elevator is required when inverted. I have a hunch that the c of g can still go back a ways. Snap rolls seemed a bit mushy to me but hopefully it is just a matter of finding the right amount of elevator and rudder to make them crisp. Seemed pretty stable in upright harrier (not much wing rocking). Haven't tried inverted harrier yet. Tried hovering at around 80' up. Too early to draw conclusions on that.

I will need to find another way of attaching the wheel pants as the solder joints to the mounting plates broke from vibration (I kind of expected that).

All in all, I think we may have a plane here. Stay tuned.

Dave

P.S. By the way Tom, I did close up the aileron gap with white electrical tape.

[Tom Hastie]

Congrats. Glad to hear it's flown. Can't wait to see it in the air sometime.

I was gonna ask about sealing the aileron gaps. Good to hear you did it. I've flown before and after with comparable aileron gaps to what you had, and found a large difference in roll rate.

Regarding knife edge, if you need high throttle to hold knife edge, you might be getting servo blowback on the rudder. One experiment to try is to move to the outermost hole on the rudder horn, and the innermost hole on the servo head. This will give you less throw, but more mechanical advantage. If knife edge is improved, you know you need a torque-ier servo.

How's the trim inverted? That will tell you how much further aft you might want to move the CG. I like to have mine so I just need a breath of down elevator when inverted. (The further aft your CG, the less down elevator you'll need inverted). Moving the CG aft and using less elevator throw should help sharpen the snaps.

Tom

[Dave_Sawatzky]

Thanks for the feedback Tom. All has been duly noted. Just an additional bit of info... when I got home, on close inspection, I found that 2 of my 3 rudder hinges had let go... that may explain why it had less than ideal rudder function. In fact, the majority of the hinges on the plane show signs of coming out.

The reason? Well, I have had problems in the past with CA hinges tearing (not coming out, but actually breaking in half). A certain club member who shall remain nameless (but whose initials are A.B.) recommended a technique of making a line on each side of the hinge with crayon at the point where the hinge flexes. The idea is that that part of the hinge doesn't get saturated with glue and therefore mainatins a greater strength. The problem, as I have now discovered, is that the glue doesn't get to any part of the hinge where it can start to wick because it is blocked by the wood and monokote where the hinge enters the control surface.

I have pulled out all 10 of my aileron hinges and found that there was virtually no wicking of glue into any of the hinges.

So I will be replacing all my hinges before flying again. Hopefully I will see an improvement in rudder authority with all 3 hinges working properly.

stand by for further updates.

Dave

P.S. Hey nameless club member whose initials are A.B. You might want to check the hinges on that goegeous black and red Cap 232 before taking to the air on your maiden flight!!

[miketoner]

Really glad to hear that your maiden flight went so well. looking forward to seeing Tantrum in the air. On the maiden flight, it is a good thing to fly a little conservatively, with nothing too drastic.. except maybe for a harrier, or a waterfall, some knife-edge flying, a rolling circle, not to mention a blender... ;)

[Dave_Sawatzky]

OK, I'm the one with egg on my face. Turns out that when you use this crayon technique, you are supposed to drill a hole in the wood through which the CA can travel... OOOPS! Not to mention that my pull tests were too gentle to catch the problem. Humble pie... my favorite desert!!

[Dave_Sawatzky]

I'm up to 7 flights on the Tantrum now, the last 5 of which have been made with properly afixed control surfaces. The previous complaint of ineffective rudder has been invalidated. Amazing what a difference it makes when all rudder hinges are sound. I'm now very pleased with the overall performance (which I would say is very close to the Funtana .40... this was the design goal). Knife edge flight is now excellent although requires some mixing to remove some minor roll coupling. On high aileron rates, rolling harriers are fast, but easy to control... makes me look much better than I am! Hovers are stable and pretty easy to maintain. Maybe the Funtana is going to be a Tantrum wannabe?

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