Thread: Discussion ST Model ASW28
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Old Jan 07, 2009, 03:19 AM
Mr_Cash is offline
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Originally Posted by evo62
I found it porpoises really easily so I might try reduce the elevator throw. It was a bit harder to fly smoothly then I though it would be, maybe the short fuse and long wingspan? ... clovus
Check the neutral transmission position of your elevator. Is it perfectly flat?

If its up, twist the control horn to bring it down to flat. Retry.

If its flat, twist the control horn to bring it to slightly below flat. Retry.

Can you shift any weight forward, without adding weight? Such as shifting the battery forward. If so, shift it forward 1/4" to 1/2" at a time, and retry. Keep shifting forward, until your at the max forward, or at the best flight glide result. Experiment to find the best position.

Note, where the center of gravity (CG) becomes, as you shift the battery forward, and back, and compare that to the factory recommended CG.

Generally, if porpoising, you need more weight forward, or more down elevator while at the transmitter neutral position, or both.

Sometimes it flys better, at different CG positions, than what the manufacturer suggests.

For example, my 55" $65 RTF Harbor Freight Wild Hawk, fly's best with both 1) the battery moved forward about 1.7" from where the manufacturers picture suggests its supposed to be, and 2) a net slight down elevator. When both these changes are made just right, it changes from a "terrible awful impossible flying plane" out of the box, to become a "beautiful sight to behold gliding glider".

In addition to putting a small spot on the underside of the wing, at the manufactures suggest CG, you might try to calculate it yourself, using the "nasa center of gravity calculator", putting down a second CG mark on the under wing.

Last, if you ever find that perfect sweet spot CG, put a spot on the under wing for that too. Or at least note it relative position, to the spots you've already made.

Generally, make only one change at a time (for porpoising, elevator down or weight shift forward), and then test, change, test, change, test, ... noting the change result.

Lets us know what happens.

(A last adjustment for porpoising, is to add weight to the front, but only do so, as a last resort, if the other two adjustments above don't get rid of it all.)
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