Well if you are going to participate in the World's largest control line Fun-Fly, you need access to a Ringmaster!
If you don't have and can't buy, beg, borrow or steal one, you will need to build one. You can buy kits from suppliers such as Brodak, RSM Distribution and others but if you want to scratch build one here are plans files for two Ringmasters. Just download the file (s) and take the file (s) to a copy shop or office supply store and have them print them at 100% and you will have full sized plans for an S-1 Ringmaster and/or a Baby (1/2 A) Ringmaster.
Have fun (I scratch build and it is a great feeling to have done it all yourself)!!
Thanks to Pat King
patdk@aol.com for these plans!