bzrogers

My Feedback: (7)

How much expo are you guys adding to your flying surfaces?

I put 20% all around for starters...Any sugestions

cmassa

I fly mine on high rates all the time with 75% expo (Futaba 9C).

Chris

smartwork

My Feedback: (5)

Well, I finally got mine assembled and thought I would post the results after I read soooooo many of these threads to get tips along the way.

Engine: Saito 100 - mounted at 90 degrees to avoid inverted engine issues, remote glow starter, and on-board glow starters.
Prop: APC 15x6
Spinner: factory and still has to be cut for APC (but included in weighing)
Pushrods: upgraded to 4-40. Pull-Pull installed on rudder. Rudder servo installed in bottom of fuse near elevator servos.
Servo Arms: Dubro Supers
Servos: Fut 3003 on throttle, Hitech 425s on ailerons & elevators, Hitech 605 on rudder
Servo horns: Dubro heavy duty - 2 on rudder for pull-pull
Tail wheel: Sullivan with custom linkage (see in post above)
Covering: factory with some added checkerboard and silver
Canopy: painted inside with Petra Silver and canopy is attached with small silver screws. Small ply blocks installed inside fuse for canopy screws.
Fuel system: 3-line - used fuel dot
Receiver: Hitech 8 with GP charge jack/switch in side of fuse
Battery: whoppin' 1700 Nicad (heavy 6 oz)

And the final weigh-in - including spinner although it's not yet cut and not mounted in the photo - was exactly 7.5 lbs on our company postal scale.

After all the reading, I was certain weight was needed in the tail for the Saito 100, but it balanced on the money at about 5.5 inches.

Looking forward to getting it to the field. Thanks to everyone who has posted along the way. It helped a TON during decision-making and assembly.

-s

RC_Junky

My Feedback: (1)

Smartwork, looks excellent. I'm sure you will be more than happy with your engine mounted @ 90 degrees, a lot less headaches at the field. Keep us posted.

coomarlin

My Feedback: (1)

I set mine up for 30% on low rates and 40% on 3D rates. But since I have yet to fly the plane I couldn't tell you what is the best. I'm just waiting for some decent weather.

Doc Halliday

I too built mine with all the mods on this forum ,tank on cg,pull pull on rudder,sullivan tail wheel and it is one fun plane to fly.The problem I was having was the YS 91 AC I had in it but I just bought a new 91 FZ YAHOO!!!!!! hopefully no more idle problems or dead sticks.



Thanks all for the help, Doc

hfleming

My Feedback: (1)

I just got my UCD yesterday. I'm putting in an OS 1.08. I'm tuning the pipe on the bench now. So far I'm around 11000 with the APC 16x4W, and I have yet to cut any off of the header. I'm concerned about midrange throttle response on the pipe. If I can't get it right I'll use standard muffler. I'm going to make a custom header to position the pipe centered under the fuse. I'll post pics when I'm done.

seanychen

My Feedback: (4)

A NiMH 1650 6V pack is 3 oz. That will bring your total weight down to 7 5/16 lb.

Changing to a 91 size motor will save you another 2 oz, bringing total weight to 7 1/4 lb.

seanychen

My Feedback: (4)

And you don't need the remote starter for the side mounted Saito, do you?

smartwork

My Feedback: (5)

Yes, the NiMH battery would shave a few ounces and so I can do that just about any time I need/want to. As for dropping the engine to save 2 oz, not a chance - After reading most reviews between the .91 and 100, the decision on the 100 became easier and easier.

As for the remote starter, nope... don't need one for the side mount... one of the reasons I went that way.

-s

seanychen

My Feedback: (4)

Sorry, I meant motor MOUNT!! The furnished mount is their GP 120 mount, weighing 4 oz. I got a Dave Brown 91 mount (not adjustable), and it weighs 2 oz. This mount is designed for OS 91 Surpass, and Saito 100 has identical mounting as OS 91 Surpass. I got this mount because I messed up too many times with the furnished 120 mount. Can someone say STUPID?

Besides, going from Saito 100 to Saito 91 would save like 1 oz, not 2. Going to OS 91 would actually add 2 oz. That's not worth the power downgrade.

smartwork

My Feedback: (5)

Oh cool. Thanks for the update on the engine/mount. I actually was toying with the idea of using the left over mount I had from my Sig Extra. It was very close to what you're describing in the major weight difference. It was going to require some redrilling that was going to make some parts a little thin so I stuck to the original. Your route sounds great though. Did the holes line up on the firewall or did those require redrilling in the mount?

Thanks again for the update.

-s

seanychen

My Feedback: (4)

I had to re-drill the firewall and relocate the blind nuts. Good thing the new holes are rather far away from the original holes, so I didn't compromise the firewall strength.

The Dave Brown mount has a circular back profile, so no hole I can drill on the mount will line up with the original firewall holes.

chris540

My Feedback: (5)

Thinking about getting one of these. I have a couple engines I could use.

1. tt 91 4-stroke
2. Super Tigre 90 2-stroke

Which engine would you guys recommend.

Do you think the tt 91 would be enough to pull out of a hover?


thanks for the help

seanychen

My Feedback: (4)

Thunder Tiger 91 4-stroke is about right. Its power is between OS 91 Surpass and Saito 100. However, it weighs 25 oz. It also takes an extensive break-in procedure. Once break-in is done, use APC 15x4W prop. It will swing this prop at 10,000 rpm, and will pull out of hover steadily no problem

chris540

My Feedback: (5)

Thanks for the quick reply. My tt 91 is already broke in so I'll give it a try.

seanychen

My Feedback: (4)

Super Tigre G90 swinging APC 14x4W should also be pretty good. It's just at hovering rpm it won't be as steady as 4-stroke.

Flyfalcons

Just maidened mine today. Only got a five minute flight in before it started to get dark. The 3001 servos held up very well, and the 4735 rudder servo seemed to be plenty. Airplane felt rock solid at 6-1/8" CG, but it did want to pitch forward during hovering. Moving the CG forward would correct that problem, but would hinder flat spin and other aerobatic performance, so I'll leave it where it is. I'm running a Saito 91 with an APC 14x6 and was able to pull out of a hover easily. We'll see how the performance degrades as the weather gets warmer, but I was only running 15% heli fuel today, so there is room for improvement there.

For some reason, I forgot to try a Knife Edge Spin. That's one of my favorite moves, so I need to remember to try that next time. I did fly a UCD before and it did nice, but not tight, knife edge spins. I did try a Blender, some Walls, some hovering, and a Waterfall. The best part about this plane, in my opinion, is how relaxing it is to fly on low rates. I think set up with low rates, this plane would make a nice second aircraft. Takeoff and landings were no brainers, and it would be difficult for this plane to get away from a pilot experienced with four channel aircraft. Don't get me wrong, I'll be wringing this thing out for all it's worth, but it's nice to not have to worry about making a perfect approach or watching out for tipstalls.

Here is a list of my mods and setup:
4-40 rods with ball links on all surfaces
Dubro heavy duty servo arms
Dubro heavy duty rudder control arm
Futaba 3001 servos for ailerons and elevator, JR 4735 for rudder
Futaba 9C transmitter, 127DF Rx, 700mah Rx battery pack
Saito .91 swinging an APC 14x6 prop with 15% heli fuel
Dubro fuel dot, remote glow igniter
I will soon be installing a Voltwatch in the cockpit

I can't wait to get some more flights in on this plane - it's a winner!

JohnVH

My Feedback: (38)

:thumbup: Thats what I like to hear

BAS

My Feedback: (28)

Flyfalcons, seems like your cg is really back there i am in process of finishing mine up have cg at around 5 and 1/2. I thought i would start there is your elevators really sensitive at that cg?? on high rates how does it handle?? thanks Bruce

Flyfalcons

Bruce,
I was a bit concerned myself, but I didn't want to add any weight and I had heard of people running 6", so I didn't think the extra 1/8 was going to hurt much. I didn't do much extended inverted flight, but I don't think it will start climbing on its own. The airplane is quite comfortable on low rates, and I am running 20% expo on the elevators at that setting. On the recommended high rates I was using 30% expo, and again, it felt fine. My 3D rates are just a little more than recommended and I am using 70% expo on the elevators there. The plane never felt twitchy, though on 3D rates I think 'responsive' would be a good term. I think the only real downside to the 6-1/8" CG is the higher rudder-elevator coupling. Tomorrow I'm going to start mixing out some of its coupling, though I am not aspiring to achieve Pattern-like perfection. I'm sure your plane will fly great with a 5-1/2" CG.

I should also mention the the plane didn't pitch-up on landing as some IMAC style planes do when they are tail heavy. The plane has positive pitch stability, but I haven't run the tank low just yet. Remember, the farther aft the CG is, the lower wing loading you will have (assuming you didn't add or subtract any weight during the CG shift).

BAS

My Feedback: (28)

Ok sounds good will be flying mine here in Iowa when it warms up . thanks Bruce

LSP972

My Feedback: (13)

<<...how relaxing it is to fly...>>

That is what sold me on one. I wish that damned boat would get here...

Steve

Flyfalcons

A word of warning: If you are using aftermarket hinges, PLEASE make sure you can go through the full range of travel with no binding at all. I just broke two of my three elevator hinges on the right elevator today, and upon further inspection it looks like I may have had some CA seep into the hinges and cause some binding. Something like this wouldn't have been a problem on a normal model with <30 degrees of travel, but with the large throws on the UCD, it looked like it was enough to snap the hinges in half. Fortuantely I was able to get the plane down safely, but that was the plane's first flight of the day and I was looking forward to really wringing it out. So far one of the most impressive maneuvers I have done with it is a Parachute. Going straight down, yank back on the elevators. Most IMAC planes will go into an Elevator at this point, but the UCD just stopped dead in its tracks. I added a little power and flew away just like normal. I have never seen a plane just stop like that, and I have been doing some wild stuff with my DP Extra. Hopefully I can get my elevator re-hinged, because this thing is a real gas to fly! Everyone watching was impressed by how the plane looks and flies.

James Devine

I have read several posts suggesting that the UCD firewall needs to be strenghened. The only way I can think of gaining access to the back of the firewall is to cut a hatch in the side of the fuse about an inch back from the firewall. I am looking for suggestions before proceeding.