lechassin wrote: ↑January 26th, 2020, 6:43 am
Mchoi595:
If your team has F1D caliber people involved, none of this will apply: warp the wings as needed, tweak a two-bladed prop, strip your custom rubber on the spot, win trophy. For the rest of us: build a straight plane that changes directions with simple, reliable adjustments that are easily incorporated into the 8 minute flight window by a novice. Luke uses only a wing shim and a rudder tab to change directions. He takes about 10 seconds to make those adjustments, and just as important, he can use just those two parameters and launch torque to troubleshoot most unforeseen problems. We know that a slight CG adjustment and offset wings help too, but we are skipping that for now to keep things simple and sturdy.
I don' t think that our F1D experience, as great as it has been, has much influence on SO. The primary influence is lack of time for SO, since an F1D build is about 60 hours! The planes and flying characteristics are so different, not a lot spills over. And remember, the two younger girls were first year SO competitors last season, so this has all been a rapid turnaround. But we only have about 60 flights on the books so far this year, we should be around 200-300 by this time.
You hit the nail perfectly in terms of importance of a straight, repeatable plane with easy, repeatable adjustments (did I repeat repeatable?). Basic trim of the plane is critical, and this year's planes are walking a fine line. Other years there was more latitude in CG vs. incidence, not so much this year. Anything flexing or warping can throw off a decent plane one week to no good the following week. the carbon spars help in this regard. Having good notebooks is more critical than ever.
Once a plane is basically trimmed, it is once again, as always in WS, matching prop, rubber, and conditions. For your particular motor stick and rubber selection, this has benefited certainly form the three-blade props.Another hidden benefit has cropped up for us. the small prop turns very fast, and centrifugal accelerations can overcome are-driven flaring and you may get prop motions that are not planned (reverse flaring, for example). A multi-blade prop will turn slower, which can help mitigate these unwanted inertial loads.
I do not think F1D experience negates the need to learn your plane, practice, test, practice, log, and practice. We have not even cut any rubber yet this year, we are using rubber form various prior years over a range of half and 1/3 rubber widths while we learn the idiosyncrasies of the plane. We have built about 15 props so far. Many have not performed at all, but all of them teach us something.
With the changing, and sometimes very difficult, rules each year, WS is different than any AMA competition. In most competitions, you can build on a cookbook of experience of other flyers over years of stable rules. In WS, especially this year, it is all about learning from scratch as fast as you can. then finding a rubber/prop combination that optimizes results.
BTW, with your flaring prop successes, you actually have a leg up on other teams in a LOW ceiling. Going to a high ceiling, any stiff prop will work, and it negates the findings you have on flaring props to some extent.
Congrats to Luke on his success! And, yes, SO is a team event. I have to keep reminding my kids, if you want to go to Nationals, you need to excel in all of your events!
Coach Chuck
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