Wattage Cap 232 - tip plates?

[Brad Trent]

A clubmate with no 'net access has asked me to pick your brains on the idea of adding tip plates to his Wattage Cap 232. He feels that it stalls much too easily in turns, and wants to know if these will help. He is using an Astro 020 and 8 cell HeCell pack, has loads of power, but may be somewhat high on wingloading. His wing was warped when purchased (seems to be common on these, from my thread search!), but has been straightened, and washout added.

If tip plates will help, what size and shape is suggested?

Brad

[Ollie]

A tendency to tip stall is caused mainly by the highly tapered wing planform which overloads the wing tips. BTW, tip stalling is an asset in snap rolls. A highly tapered planform reduces mass near the wing tips and increases roll rate.

When the plane banks in a level turn, the wing has to produce more lift so that there is enough to take care of the weight of the model and enough to provide the centrifugal force of the turn. If the air speed isn't increased then the stall margin is reduced. To retain sufficient stall margin the airspeed must be increased in the turn. The greater the angle of bank, the more the airspeed has to be increased to produce enough lift. Additional washout will provide more tip stall margin but won't do much to prevent stall else where if airspeed isn't increased sufficiently when entering a turn.

Tip plates may help the tip stall some but the added drag and weight at the wing tips may have side effects that are worse than the original problem.

[Brad Trent]

Thanks for the reply, Ollie. I'll pass the info along. This is the same flier for whom I posted a few weeks ago, looking for a replacement model for the Cap, as he feels it's traits are a little outside his abilities right now, hence the desire to tame the stall. If anyone has any suggestions for a substitute plane that will use the same power train, similar "cool" looks, but a more forgiving flight envelope, please chime in here as well.
Thanks,
Brad.