I was excited about the Wisp. This was my first 2 Bit model (Old Time ROG models with 26″ span or less) and I spent a lot of time making it look beautiful (if I do say so myself). In addition, there was additional time spent installing my first working DT. At 29 grams and 75 square inches, it just might need that DT. I built the model per plan, including the carved prop (8″D x 6.25″P) and the 3″ per tip dihedral. These two things concerned me – my intuition was telling me both were strange numbers. Then, right before I left for Muncie, I re-read the MAN article – it said “up to 2 inches per tip” but the plan clearly says 3″ per tip – very frustrating.
I arrived in Muncie on Friday with plenty of time for testing before the Sat/Sun contest. Trimming out, the plane flies, but not beautifully. It seems to pull to the right for some strange reason, and there is a lot of wing-rocking. Then there is a sharp, right-hand, spiral dive when the power is low. After testing off and on through Saturday (2 Bit is on Sunday), I bit the bullet and cut the pretty tissue, the spar, LE, and TE and reset the dihedral to about 2″ per tip. I also changed to a 7.875″ Czech plastic prop. These changes improved the flights, but it still needs more work. I was able to coax flights of 85 seconds or so, but I am still battling the right hand spiral. I am sure it is a free-wheeling issue and I hope to get it sorted out. Here is an in-flight shot of the Wisp – it sure looks pretty in the air.
The Wisp in Flight