Forget about upright flat spin, won't do it, possibly because of the pitch to gear with rudder input. Inverted flat spin however is great. I'll do a power off inverted flat spin, and it'll just parachute down rotating around CG, or close. Slowly feed in power while removing some elevator and aileron, and it'll pick up speed, but won't be as flat anymore.
DKjens

I know this has been discussed at length but any New ideas on where the CG should be I am at 5 3/8 behind the L.E. and it feels like it could go back another 1/2 in. and still land OK. any one know of any problems with C. G back that far.
Thanks Mike,

I may have too much elev. and rudder inverted it wants to pitch nose up and stop rotating.

I have only flown my UCD a couple of flights so far due to the weather, but so far it's done great. I am running 605 servos for everything but a 645MG on the rudder, and a standard servo for the throttle. I changed all the rods out to 4-40's, mounted the horizontal stab permanently to the fuse (no epoxy, I just lock tighted the bolts), used heavy duty servo arms everywhere but the throttle. I am also running a saito 100. The engine was tricky to tune, but once I got the low end tweeked, I now have no problems with loading up, or carb flooding. Right now I am using a 15x6 prop with a true turn spinner.

For all the fun things this airplane can do, the rudder has to be the only frustration I have with mine - note: this is my first "made for 3d" airplane. The roll coupling has to be the worst I've ever had on any airplane, its simply amazing how much aileron has to be mixed to the rudder, I too have about 3/4 inch mixed - is this normal for 3D aircraft? on the bright side, I was able to mix out all the roll coupling. Pitch coupling on the other hand is driving me nuts - at low rate rudder 1.5 inch of travel, I can <almost> mix it out, and its flyable. Once I get out of low rates, and go to medium setting of 2.5 inches or the 3D rates 4 inches, it seems as though it goes from pitching to the gear to pitching toward the canopy! Its so awkward, I gave up on trying to use the mixes and just hand fly it. It is fun as heck tho, with a little practice, you can snap from knife edge right into a hover just like from upright flight lol. It would be nice to be able to mix out the coupling... could do some really silly knife edge stuff then.... I have the CG at 5" back from leading edge of wing (seems to be a good balance point for inverted flight requires little to no elevator)- will it help the coupling to move it? Has anyone played with the stab incidence yet (mine is 0e-0w-0s)?
For Smartwork: I have the Saito 100 on mine - you have no worries about power. Still quite rich, I'm running 8900 rpm on a APC 16x4W (peaks at 9250) on 15% nitro/20% oil heli fuel approx 600ft PA- hovering at about half stick, it doesnt rocket out of a hover, but it does pull out with authority. I havent tried a 15x6 yet, I suspect as many have already stated that would be the right prop for this combo - I have yet to use full throttle for anything other than pulling out of a hover or bailing out of high alpha stuff. Also, while you dont absolutely have to have it, consider a cline regulator if you invert the engine, its just makes life easier when it comes to setting the low needle - I can idle at 1000 rpm all day without loading up, and the transition is very nice.

About to hinge my ailerons. One person mentioned using after-market hinges to space the aileron off the wing 1/8" (but sealed gap) in order to allow more aileron travel.

How does everyone like your aileron performance with the CA hinges? Working OK or wish you had more travel?

-s

smartwork

Not that I am using them yet, I am able to get full 3D throws and I used the stock CA hinges, and the gap is negligable.

desertrat
I don't think is normal for 3D planes to have this much rudder coupling. They just tried to make the rudder to large and got way to much rudder above the center line of the plane. Other than remaking the rudder and slanting the hinge line back at the top I living with it is the only choice.

Mike,

is that plane doing a flat spins, and blender?

I had my throttle rod connector slip and my Saito 100 was in pretty much 90% throttle for about 7 minutes...

Lots of vertical motion with flat spins down, and throw in a couple hundred loops...

Just kept it pretty high and floated it down to the runway.

Also per the other "coupling" threads...

There IS alot of rudder coupling. But it'
s not nearly as notcieable at low speeds... the speed which I feel this plane was MADE for.

It's not really a speed demon, and those mondo wings are horrible for snaps and rolls anyway. But for low speed, high alpha moves it is sweet. Also as a slower speed "pattern" trainer, it's not to bad...

I hope someone comes out with a carbon fiber gear for it... that gear that DOES come with it is like 4 lb gear on a 7 lb plane... I've got a "spring stiffenener" between the 2 sides.

upgrading to the 4-40 rods is a must, the 2-56 crap they included will simply bend up like a wet noodle.

Try scuffing up the 2-56 rod with 80 grit, then 3M77 some Uni Carbon, (the thinnest you can find) wrap the Uni 2~3 times around the rod, then soak with thin CA.

Super strong, super stiff and a lot lighter than 4-40 rod.

Every little bit helps, I got mine down to 6lbs 7oz w/Satio 91.

Darrin C

Hi,

I am also using a saito 100 inverted. However, I am having serious carb flooding problems. Any suggestions?? How did you keep yours from flooding.

My high speed needle is set at 5 turns out as recommended from the manual.

Any suggestions would be greatly appreciated.

Scott

Not sure WHEN you are getting flooded, but I ALWAYS empty out the tank and then "run" the remaining drops out of the engine at the end of a flying session. Otherwise, it'll pool and "gum up" around the glow plug and make it harder to start next time around...

otherwise you are running still too rich...

I HAD THE SAME PROBLEM EXPECALLY AFTER FUELING,, I PINCH OFF THE LINE NOW WHEN FUELING SEEM TO HELP.. I ADDED AN ON BOARD EGNITION TO.. WHICH HAS SOLVED MY LOW IDLE PROBLEM..


BRUCE

5-turn out is only for break-in. If during break-in your engine is flooded, keep the glow starter on.

After it's broken in, you should run about 2-turn out for another gallon for a rich, yet flyable setting.

5 turns out is the recommended break in setting to be extremely rich. The needle ends up at between 2 and 3 turns out when leaned out.

The flooding wont be so bad once you lean it out to normal flight settings, but you have to have a hemostat or something when you are fueling - 5 turns is WAY rich, I bench ran the first 1/2 gallon through mine as I could see there was going to be a problem trying to run that rich inverted. After a lot of tweaking, I finally got mine to a flyable state inverted, but the low end never really was <right> until I added a Cline regulator. The Cline makes all the difference in the world, granted at 60 bucks its a tad pricey, but for the convenience and performance, its well worth it.... and you can move the fuel tank back to the CG

I have just spent an afternoon experimenting with the new (but broken in on a bench) Saito 100 mounted in the UCD inverted. I have arrived at a few tips to share about this setup.

1 - Starting. I have attached a 90 degree bent piece of pushrod into the needle valve in order to be able to judge exactly how far out the proper setting is in number of turns. I set the position of the bent pushrod pointing directly backward when at this setting. I counted the number of turns from that position to having the needle valve closed completely. I can now open the needle valve from completely closed to the proper setting in just a few seconds. Fuel the plane with the needle valve closed. Advance prop clockwise to the compression cycle so the starter motor can get a head start. Attach the glow driver. (I have a remote one just above the wing) Open throttle to just above idle. Open needle valve to proper setting. Punch it with the starter motor. Starts first time, every time.

2 - Settings. The low speed idle will need some adjustment. This is not because the setting is that far off with the engine being inverted. IMHO, it is because the range for the proper setting of the low speed needle is very narrow in comparison to an upright one. This is how it seemed to me when trying to get a reliable low idle, with good transition. 1/8th turn in any direction other than proper was not nearly as good.

I the tank has any fuel in it at all when the motor stops, and you are near the plane, be sure to close the needle valve.

Also, when setting the low speed idle, and you think you have it good, pick up the tail of the plane so that the fuse is level. You should hear very little (there will be some) change in the idle speed.

Just some Texan experiences with this combination that I thought I would share with y'all.

For those of you that are running Saito's with cline regulators on your UCD's, how about posting some detailed pictures. I've been contemplating the cline, but after looking at my setup it seems like there is very little room between the carb and the firewall to fit a cline.

SO...what is the best APC prop for saito 100?

I have now put a cline regulator in mine to improve the general running of the engine. I also took out the stock tank and installed an 11 1/2 ounce bubbless bladder tank from Central Hobbies. ($18.00). I did this to be able to place the tank closer to cg, and to be assured a good fuel flow regardless of the attitude of the plane. I placed the cline regulator on about a 1.5 inch length of tubing curving back and into the area underneath the carb. (Remember, the engine is inverted. This would be the area above the carb if looking at an upright engine.) I have not flown the plane yet, but I will post some good info on it when I do.

Most peopel are using 15x6 props. There are also those that are using 16x4w. I've only ran mine with a Zinger PRo 15x6, and it was quite good, but I'm sure an APC would be even better.

I'm running an APC14x8 during break-in (about there now) and will switch to the 15x6...

The more I fly this plane the better I like it...

I flew mine over the weekend for the first time. I am truly impressed. I have a new OS 91FX on it which is running through a perry pump. Once I got everything set I didn't have to touch it all weekend. (about 12 flights) Fuel tank is on the cg which worked out great. Cg is at the rearmost point indicated in the instructions and needs to go back a bit more to suit me.
Absolutely wonderful plane!!!!!!!!!!!!
Okay one downfall is severe tuck with heavy rudder but I can live with that.
First time I tried it, I did the most beautiful knife edge spin I've ever seen!
basmntdweller

basmntdweller

I'm sitting here trying to figure out where and how to mount my Perry pump. This is my first time with a pump and I have several questions:

* Where did you mount it?
* Do you use muffler pressure to the fuel tank?
* How are you fueling the tank?
* Are you using the stiff semi-flexible urethane tubing to the crankcase or just fuel line tubing?
* How important is it to have the vent hole down?

I hope that you don't mind me asking? Thanks