RE: Hangar 9 produced the Twin Otter!
For those interested in flying 3 blade props. I have found the MASter and Graupner's to be really heavy. The Master are not efficient at all, the Graupner develop more thrust, but also are power hungry. It simply takes extra amps to turn these.
The solution. I started using EMP propellers, from Hobby King. They call them TGS sport. These propellers are actually designed for electric, have a blade shape very similar to APC electrics. They are far lighter than anything out there designed to handle any power.
They make an 11/8.5 and a 12/8. The 25 Eflite might turn the 11/8.5, while the 32 will turn the 12/8 ( actually close to scale size).
An extra bonus is the price, about a third of the others.
I'm currently using 12/8/3 EMPS on a Twin Otter (not Eflite's) and a 84" Buffalo, along with a 15/8/3 EMP on my 96" Turbo Beaver. I have found them far better balanced out of the package than any of the others.
I used the Dubro 2" 3 blade spinners, had to open the blade notch, but they spun up fine. I believeHobbypartz carries them in the US FWIWflytreetimes