3rd

The UCD has bad coupling from rudder into elevator and aileron, as we all know.
Has anyone yet tried to reduce the height of the rudder? This could easily be done by coming down to the first cross member and cutting the top off. The plane has way too much rudder anyway. I really believe this would be benificial, and am toying with the idea of doing it.
Has anybody else tried this idea yet?

Landing Gear Replacement
With the stock landing gear being so soft, what replacement gear can be used?
I'm running an OS 91 Surpass on my UCD and had siphoning problems right off the bat. So I took it in for surgery and lowered the tank. Haven't had a chance to take it out for a test run. By looking at the bottom you wouldn't know that anything had been done to it, as I used the old tunnel and made it shallower. I dropped the tank 1.5 inches, and it was easy to do.
Loren

I waited till the crowd thinned out a little at the Muskogee Fly-in today, then fired up the Saito 100 and gave the UCD a test flight. I REALLY LIKE THIS AIRPLANE! C.G. came out at 5" with where I mounted the battery pack. I will move that back after a few more flights. Didn't try too much as this was only my 6th tank of fuel on the new Saito and I didn't want to push my luck at a fly-in on the maiden flight. Vertical uplines became unlimited at 3/4 throttle, and this thing is rock solid! Flight control authority is brisk and precise even at low rates! I never even went to high rates for the hovering with the vertical climbout over the top! Landing was easy, even as nervous as I was. Can't wait to get her up again and start wringing her out. What an airplane!

I've just read the whole thread...jeez it is a long one. My question is about using a OS 1.08 FSR, no one that installed one gave a performance report. I plan to use it since I have it laying around along with 425BB's and one 605BB on a 6 volt system. I plan to go with a perry or cline on that engine so that I can move the tank to CG from the get go. Which one is better. Give me any other tips that are hot off the press.

thanks,
LeRoy

I just took mine up for the first time yesterday and went with the Cline Regulator and a Saito 100... it worked flawless... no problems. It's amazing how much pressure builds in the tank. I would recommend the Cline to anyone, clean simple and effective... the price is pretty steep however, $60 ouch.

I put the OS 91FX in mine with the perry pump and tank on CG. I have about 15 or 20 flights on it now. I have not adjusted the pump yet but the engine is running pretty rich through the mid range. I'm not real sure which way might improve it though. The obvious would be to reduce pressure but that may have the opposite effect after adjusting the main needle to compensate for the reduced pressure.
The Perry is only half the price of the cline. That's worth a couple gallons of fuel and burning fuel is the best upgrade you can get.
later,,,basmntdweller

I am going with the perry pump to start with. The cline requires that I tap the crankcase for a pressure source, where the perry is just a bolt on. I have to go with simplicity in this case. I still want to know how everyone thinks the 1.08 will do in this application.

LeRoy

Yes the perry is only have the price of the cline, but with the cline you won't have problems with inconsistant richness levels over the throttle band. There are no finicky adjustments on the cline. Just consistant fuel delivery throughout the entire band.

NOSRAM,

I decided to do what you suggest about the rudder coupling issue. Although I haven't flown it yet I believe it will be a helpful fix. I plan to fly it tomorrow (weather permitting). This time I took pictures of what I did throughout the process and will post them sequentially over the next 6 posts including this one. The whole process was quite easy and took less than an hour to complete. Overall, after cutting off the top of the rudder and then adding a new cap for strength and to get the new desired height the rudder height was reduced by 2.25 inches.

This first picture shows how I simply cut away one side of the monokote down to the first cross member of the rudder. This gives visible access to everything that needs to be cut.

Here is the 2nd picture of 6. This picture shows the cut away portion of the top of the rudder. Note, I never peeled away the monokote from the other side (didn't have to).

Here is the 3rd picture of six. This picture shows the rudder remaining after the top has been cut off. The tail section looks kind of dumb at this point. The cut off portion is laying on the table. I used the exacto saw blade shown below the rudder to cut it off.

Here is the 4th picture of six. This picture shows the new top which was added to the rudder for both strength and to get the new height. It is a solid piece of light balsa which is 5/16" thick. I just eye-balled the shape and glued it with thick CA. My UCD is currently balanced at 6" so I didn't care if I added a little extra weight to the tail but it really didn't change the balance point much that I could tell.

Here is picture 5 of 6. This picture shows the completed tail section. I just used white monokote and plan to re-trim more color after I'm sure it flies OK.

Here is picture 6 of 6. This picture was included to show the entire fuselage and to give an idea of how the overall proportions look after shortening the rudder by 2.25".

My Saito is working awfully well without any pumps.

Of course, it's upright !

mt

Definately give us a flight report.

Excellent, I was wondering on my way home how to word the email:
Fixed Wing, have you engineered the rudder shrinkage yet?
No need, you have the job done, excellent. Better hurry and try it before DoDad sells his

I was at our flying sight yesterday with my UCD 3 D. I was having trouble in knife edge with mine, pulling to the left and rolling to the left. I mentioned this to an experienced modeler about this problem and ask him to fly my plane. He took off went into knife edge straight across the runway. He then did a knife edge horizontal loop. Then he did a knife edge loop in the vertical and commented at the top of the loop that the plane was a bit nose heavy to do it well. I watched him as he flew the plane and did not put in controls on the elevator or aielrons. I quietly said maybe I need more practice. He politely nodded. Will be curious to see if this improves performance of the plane by cutting a couple inches off. This pilot proved at least on my plane it wasn't necessary.

Has anyone flown one of these with on 70 4 stroke? Has anyone mounted the engine right side up or side ways instead of unside down?

Well I flew the UCD for the first time today after having removed the top 2.25" of the rudder (see earlier posts and pictures). It flew as hoped for with very little coupling needed. The plane was as stable as it has always been in normal flight. There is no apparent loss of rudder control (remember, its a huge rudder to begin with) and the plane still does knife edges and knife edge loops with ease but now without the need for a lot of mixing. Transitioning from a left to right or right to left knife edge can now be done without a lot of roll or elevator correction. It's now flyable on hard rudder maneuvers with just manual use of the sticks. However, after several flights I did reset 3% elevator mix (used to be 12%) and no mix for ailerons (used to be 5% mix). Flat rudder only circles are very easy now both upright and inverted. There is less wing rock in harriers and hovering even seems a bit easier. I wish I had done this from the beginning but who knew? I agree with NOSRAM's earlier post stating "for all its good points its a shame that Great Planes couldn't have finished the job, with no rudder cross coupling, and a tank at the correct height."

That's the best news I've had today.
Wish I had the same belief in myself!! Guess I will do mine now, unless you are offering. Are you going to tell Doodad?

What if I ADDED about 1.5 inches of rudder BELOW the rudder?

If you took 2.5" off the top as well, it would be perfect

I would highly recommend that if you shorten the rudder (originally designed as a "balanced" rudder), you should also implement a pull-pull configuration vice a single pushrod. Snipping off the forward leading section of the rudder (the part that attempts to "balance" the rudder) would then require more torque to properly control. I guess if you are a using high quality, high torque (pref. coreless) rudder servo (single pushrod), you could get away with it. Just my 2 cents worth.