Hi............I think I posted almost every relevant photo of the highly modified Senior Telemaster I built. Do a thorough look see and you'll note among other things that as a result of suggestions that the flaps were cut in half. From 20" to 10". Turned out to be more than enough.

Experience.........putting flaps on a Senior Telemaster is fun and entertaining but really not needed and adds the weight of 2 big servos.

If you add flaps, you can make them any size you want. If you look closely you'll see posted photos of both the 20" and 10" versions.

Opinion: Doing it again I wouldn't add flaps and would rather build more to save cost, weight and time. The two piece polyhedral wing however was/is a winner. Super strong and very, very stable. Trims out beautifully for hands off giant circle climbs at about half throttle.

I did NOT use the trialing edge stock supplied with the kit to make either the flaps or the ailerons but rather purchased a denser 1 1/2" TE stock.
I wanted to have about equal aileron control surface area with about 1/2 the length. Worked very well and I would repeat the design.

For what it may be worth.........I made extensive modifcations to the Senior Telemaster for added strength and of course I thereby added a lot of weight. In re-evaluation of what I was trying to do I think I would and likely will build BTE's Flying King. It is both a stronger design and a superbly prepared kit. In fact there's really no comparison it kit quality.

Don't know of your building experience level but doing what I did with the Senior Telemaster was virtually a scratch build......especially the wings.

Best of luck, Blue