Tim,
if I may make a suggestion, run the pressure to the Uniflow not the overflow, I think it will work better for you
How did portland go for you?
Uh...
It's one of those concatenation of stupidities that result in disaster. Much like Chernobyl, except that the results were only mildly disappointing instead of earth-scorching, and the committee that made all the errors only had one member.
To start with, I crashed the Waiex the weekend before. I hadn't been flying for over a month because of all the rain, and I get hammered by allergies every spring. Moreover, the
last time I had flown the Waiex, I had brought the wrong handle along with much wider line spacing, and it had been an absolute handful. Add to that the fact that I was having a really bad engine run. So there I was, with a plane not flying right, half of my brain cells on sick leave and swimming in snot, and an engine running way too rich. So do I bail, and just practice my level flight for six minutes? Of course not -- I try to fly the pattern. So I scraped the top of the Waiex off, by doing an outside loop whose bottom line was trying to be six inches below the pavement.
(An alternative suggestion can be brought forth by observing that the
only times I have
ever crashed that Waiex to damage it is when
Richard Entwhistle's dog is watching me fly. You make the connection).
That's not enough to give me problems last weekend.
Go back a bit: my #2 plane is a Sig Skyray that my nephew sold me ($10 with a barely-run OS FP 20 on it -- tee hee!). I reworked it with all the Brett Buck mods. The two-wheel landing gear used up some tank space with wires and hold downs and stuff. So I made a tank. I go and make this dang tank for the Skyray that's all pretty and everything, but it is ambiguous about which is the uniflow and which is the feed tube (they're right next to each other, etc.).
Since the Skyray came with an engine that's much nicer than the OS 25S that I built the Waiex for, I've just been swapping the one engine between two planes (if I splatter that engine I'm hosed). So, naturally, I swap the engine from Waiex to Skyray for the contest.
There are
no decent flying last week -- even the contest was rained out Friday. So I don't fly the Skyray until my first try Sunday. It flamed out on the first flight, after four or five maneuvers. Dang -- I thought I just had it way too rich.
Then comes the second flight. Same thing, only this time I flame out in the middle of a loop. I manage to save it (to applause -- thanks guys). To pile embarrassment on indignity, I had forgotten the wingover on the second flight. So I was offered a chance to try again -- but I still hadn't figured out what was going on with my engine, and didn't want to risk flaming out over concrete during a 3rd -- and possibly more splinter-ific -- try.
So, that was Portland last weekend. But I got to watch Paul Walker fly -- twice. And I got to talk to all these folks that I never see. Scott Riese was nice enough to point out good and bad maneuvers for about half a dozen flights, in response to a question I had about hourglasses, and I realized that I'm making my corners
much too tight on the squares. So it was worth the trip, even if I did go home with yet another prize for coming in last.
And, I know what it looks like when you get feed and uniflow tubes crossed -- that's got to be worth something.
Here's a sketch of what I'll build if I feel the urge to put uniflow and feed tubes right together, ever again. I'm not sure how one goes about lettering 1/8" brass or copper tubing (engraver?) -- but it's what I'll do, none the less.