SonexBuilders.net

Greetings,

After two whole flights <g> on my 912UL Onex, the main thing I noticed is how much adverse yaw there is. Most of my time is in RVs and I was surprised how much more adverse yaw there seems to be in the Onex. The rudder is also very light and surprisingly effective. I wonder if this is all partly related to the small vertical stab?

Takeoffs and landings seem very honest for the tailwheel version. Stall "seems" (pending airspeed verification) lower than advertised, even though I have the short wingtips. The overall flying qualities seem very light and sporty.

The biggest issue is the brakes, which are terrible. The project already had the machined hub mechanical brakes when I bought it, so I thought I'd leave them. That seems like a mistake in retrospect. Basically they pulsate, squeak, and are too weak to hold for a proper runup. They also have a tendency to stick when they're on, though that could likely be fixed by rounding the corners of the actuator as they recommend. I'll have to replace these soon to keep from embarrassing myself, and also to be able to put the wheel pants on. I didn't bother installing those since I knew the brakes were going to be questionable.

My Dynon D180 has been misbehaving as well, and I may end up having to send it off for repair. Fortunately the EFIS side has been perfect, but the EMS side has been dropping out. It dropped my engine readings for minutes at a time on the first flight, but after pulling it out and verifying some wiring, it only lost readings for a few seconds at a time a few times today. If it can keep liming along, I may just order an MGL iEFIS MX1 and hope it gets here before the Dynon quits working.

Cheers,
Rusty

Pulsating brakes - make sure the drums are truly centered on the wheels. Snug bolt holes to wheel does not necessarily mean they are. If the drums are off center to the wheels - the brakes will pulse. The wheel set up information sheet mentions the point without telling you why it is important.

Sadly, slop in the holes is well known Azusa feature. Last week I spent an afternoon trying to get them as well centered as possible. They looked 100% better when I got finished tweaking them, but if it made any difference I sure can't tell it. My plan now is to try to live with them until I can replace them with something better. I'm still thinking of mountain bike disc brakes. I used them before on another plane, and I have the parts sitting on the desk. I'm trying to talk myself into just clicking on the O'Keefe order page to be done with it though.
Rusty

I put Matco brakes on my Onex and I couldn't be happier with them.

I can verify that the Aeroconversions hydraulic brakes do NOT have the stopping force needed (for a differential brake set up.) They are marginal for low speed taxi but worthless for directional correction on landing in a crosswind.

I ordered a set of the O'keefe hydraulic disk brakes for the 5" Azusa wheels on Feb. 24. They were in stock. It is now March 15 and they still have not arrived. They said they were out of town and said their son would ship them right away but I am still waiting.

I didn't know how much I relied on brakes until I didn't have them. The Y tail in a crosswind with the long moment arm of the fuselage needs all the help it can get to keep it straight on roll out. Fixing the pivot angle on the Flyboys tailwheel was a major improvement. At least I can get some steering to keep it on the 100 ft wide runway. Now I just need effective brakes.

Rick Caldwell
Xenos 0057 Ph 1 underway

All good info to know. I'm sure the full Matco tire and wheel option is probably best, but of course the most expensive as well. I really dislike hydraulic fluid and will try to stay with mechanical discs if possible. I fly out of a 6500 ft runway, so heavy braking isn't something I'll be needing very often. I just need enough braking to hold during a runup, and it would be nice if they don't squeak, squeak, squeak... and make everyone on the airport stare at me :-)

Rusty