Visual Aid (Loop Size)

[Motorman]

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[Brett Buck]

Help me check my math. If my plane is 70 feet from handle to thrust line and I wanted to make a circle out of coat hanger wire to hold at arms length (3') that would represent the size of a loop, how big would the wire circle be?

I got 30" dia.

   That's a lot closer than your first edit...
   
radius of the loop is 3 feet x tangent(22.5 degrees), so about 1.225 feet or 13.5" 2x to get the diameter = ~27".

    Brett
   

[Tim Wescott]

I think it works better to get a good feel for where 45 degrees up is, and possibly for 45 degree spacing on the ground, and then adjust your loops to that.  But I could be wrong, and it's an interesting approach.

Note that the line length doesn't matter as long as you assume that the lines are pivoting around your eyeballs: 45 degrees is 45 degrees.

You split a bunch of ping-pong balls in half and mill a slot corresponding to the path taken by the plane for each maneuver, then hold it up to your eye as you fly them, to make sure you're matching the pattern.  Brett, or other pilots who were flying in the Pacific Northwest in the decade before I started flying could comment on the efficacy of that approach  .

[Brett Buck]

You split a bunch of ping-pong balls in half and mill a slot corresponding to the path taken by the plane for each maneuver, then hold it up to your eye as you fly them, to make sure you're matching the pattern.  Brett, or other pilots who were flying in the Pacific Northwest in the decade before I started flying could comment on the efficacy of that approach 

   Oh, Rich had something like that, but, more on point he had a loop radius gauge that had a about a 3" string on it, he would hold or tape the string to his cheek, then look through concentric wire loops, each of which was calibrated to show various corner radii.

    Brett

[Trostle]

One way to visualize the diameter of a 45^o loop is to mark a 45^o angle on the surface (pavement or floor or grass) you are standing on with two pieces of tape.  Length of the tape does not matter, but the longer the legs, the better the visualization.  The edges of the 45^o loop would be tangent to the vertical lines above the tape markers regardless of the line length.  A 45^o loop is smaller than what most people fly.

Oversize loops are even more apparent when watching the horizontal eights which are to be 90^o wide which is 1/4 of the circle diameter.  It is fairly easy for a judge to visualize this 90^o section of the circle.  It is surprising to see how most horizontal eights approach 120^o and in the wind, those eights approach 150^o.  Yes, the better pilots do a better job of keeping their loops closer to 45^o and their horizontal eights closer to 90^o, but when they do, many will say they are flying too small.  (Yes, some pilots do fly too small, but their scores should not be penalized any more than the pilot who flies the same degree of oversized loops.)

Plackards placed at the 45^o segments around the circle are useful tools for the pilots to size their maneuvers, but it takes practice to use them.  They are also useful for the judges.  Unless the pilot or judge is familiar with using them, the placards can become a distraction and have very little use.

Keith

[Craig Beswick]

Motorman,
check your PM.

Craig

[Tim Wescott]

   Oh, Rich had something like that, but, more on point he had a loop radius gauge that had a about a 3" string on it, he would hold or tape the string to his cheek, then look through concentric wire loops, each of which was calibrated to show various corner radii.

    Brett

Dangit, if only I'd gotten started 10 years earlier.

These days you could make that arrangement more secure by getting a nose ring, and using a clip.

[Tim Wescott]

... Got to the contest and was told my stuff was below 45 ...

Everybody does their maneuvers big.  It may be the judges that need calibrating.  Get confident with your maneuvers, and then use that as a basis for arguing with the judges!

[Brett Buck]

Everybody does their maneuvers big.  It may be the judges that need calibrating.  Get confident with your maneuvers, and then use that as a basis for arguing with the judges!

    There are definitely people who *do* routinely fly undersize, although they are in the minority. Usually their figures tend to be unrecognizable, and it is *very common* to coach people to fly larger in order to better manage the shapes, bottoms, precision. When people start to learn to fly square maneuvers, they typically make them *much smaller* than they should be or can be.

     Or, they fly a lot by themselves, and can't tell the difference without resorting to mechanical measurements. I know this because *that's exactly how I started*, I flew day after day after day, nearly every day for several years,  with angle and height markers to indicate 5 feet and 45 degrees, and at times, 5 foot radius markers. I was nailing the 45 degrees and at least attempted to nail the 5 foot radius. The first time I flew with other experienced modelers, Dan Lutz (one of the local fliers in Lexington, KY) ran out of the pits and screamed at me *MUCH BIGGER*! Because while I was hitting the 45 like a laser beam, my airplane and engine were in no way up to the task, the shapes were unrecognizable, and I would get a better score if I opened up the maneuvers and gave up size accuracy for superior shape and precision accuracy.

    I have told people to fly larger on many occasions, because while they might be flying the right size or even too small,  they are committing  many more serious errors in the effort and may be beyond the capabilities of their airplane, and their score would be greatly improved by flying bigger but more accurate and precise shapes.

   And in any case, no matter what the comment or advice, the judges have usually seen thousands or tens of thousands of flights from all sorts of skill levels, and are in perfect position with perfect perspective to see what might improve the pilot's score, because they just got done figuring out what errors the pilot committed.

    The point of stunt competition is *not* to more accurately execute maneuvers - it's to make the judges think you are more accurately executing the maneuvers.   Advice like that, or even just the posted results, are *always,* repeat, *always* critical input. It's really the only evaluation that matters, far from arguing about it, it is telling you *exactly* what you need to know. Take advantage of it!

    Brett