We flew ringmasters (and crashed them) during my earlier years. I agree that they are beautiful and tough. Our problem was as kids, we thought that the greater elevater angle the better. You guys have taught me different. That may be why we crashed alot of Ringmasters (and others through the years). This is a great place to find knowledge about flying. Thanks again
The eye of the beholder, I suppose. Jim 'Uncle Jimby' Aron's Ringmaster (cover model for the RSM Ringmaster Kit) got 20 appearance points at VSC.
Tough, unfortunately, it isn't. Fortunately, given that the world has been graced with close to 1,000,000 of them over the years, the weak spots are well-known. The worst of all, by far, is the tendency for the fuselage to crack right at the wing leading edge. With the stock parts this will likely happen before you even get the engine started the first time. The stock doublers are of such poor quality and of such a shape that it's essential to replace them with real plywood that goes back much further. AND use the "t-joiner" as Tom described above, AND the leather fillets (or something similarly tough) and pass on the Fox 29/35 unless it's tricked out. If nothing else, if you use the stock doublers, the engine will keep coming loose until the doublers have been completely compressed, from 3/32 start with, to about .005 after a dozen flights.
The most dangerous problem is the bellcrank mount. The same crummy plywood just flat-glued to the spar will let go pretty quickly when subjected to the pull-test. There are a variety of methods to fix this, but at least replace the kit plywood with real 1/8 aircraft ply and reinforce the connection to the spar. And don't use model cement to put it together.
If you fix the first two problems, and use (as is highly recommended) a small, high-rev motor, you might encounter the third problem. Since we started running better engines with better props (a 15FP works remarkably well on a kit Ringmaster), learned to cut the elevator travel to a reasonable amount, and generally learned how to trim, there have been a spate of Ringmaster wing failures. The reason is pretty obvious - the structure of the wing is absolutely terrible. All the wood is right down the middle of the structure, which is the worst possible place to put it.
Back in the good old days with Foxes and +-60 degree "flipper" elevators, and kit leading edges carved from what appeared to be solid hickory (or balsa that closely approximated that) it never cornered hard enough to put any stress on the wing. Now. we are all clever guys who use the finest contest balsa, Veco 19's, and +-20 degree elevators that make it do full AMA stunt patterns with panache and decent scores. That is, until the wing folds and comes fluttering down at your feet.
So everybody needs to be careful trying to shave off weight. For reference, after seeing about 5 of them "clap hands", DO NOT, under any circumstances, do ANYTHING to remove "weight" from the first open rib bay, In particular, while it's fine to hollow out the leading edge starting about halfway out on each wing, DON'T do it in the first rib bay after the sheeting ends. If anything, you need to ADD something there to strengthen it.
Trimmed and powered correctly (and the *power* is almost everything) the airplane will fly recognizable square 8's, hourglasses, or just about anything you can think up and can be nursed through to 500-point patterns if you are really good. Not bad for something with a reputation of having a tough time doing the OTS pattern.
Brett
Topic: Ringmaster Technical Questions (Read 7602 times)