RE: My new Dick Sparplous Challenger .40
Very nice indeed. One question though because it's hard to see in the photo. Does the pushrod to the elevator have a support around it in the centre to stop it from flexing? If not then you might find you'll suddenly run out of up control on a hard turn. The pushrod is then in compression and will try to bend. Glad to see it uses a clunk tank too, I've had a lot of success with them set up as Uniflow, but you could try packing the rear end out maybe 1/8" to 1/4" so all the fuel will get used. In flight the model will yaw out a little so angling the tank compensates for this and you'll most likely get a much cleaner stop at the end of the flight.