U Can Do 3D
 

Thanks a million for the pics, I guess I have another thing for my to do list...

David

Well....
 

Flew mine for the first time today.....

This is a keeper....

I need to work on the KE tuck and engine thrust. This plane is truely a blast.......I lost one aileron servo (came unplugged during flight) and flew for a while with little loss of roll speed. This plane does the best slow KE that I have ever flown. Looks a lot like the 40 % Edge's do.......

The Saito 100 with the APC 16x4 W prop is killer......

I really like this plane so far.....

Pug

about 3 weeks in
 

I've been testing mine now for about 3 weeks, and like I thought after my first trip to the field, I still believe it's a keeper. This thing is a blast to fly, simple as that. Very forgiving airplane.
I've tested a bunch of different props on my SurpassII, most recently the 16x4W with very favorable results. This engine is very easy to use, and has a lot of torque for a 91, It'll pull this airframe out of hover with anything from a 14x6 thru the aformentioned 16x4W. A flying buddy brought his UCD out for the first time this week and gave me some stick time with his Surpass on a 15x6, and I really liked it, that's about the only prop I haven't tried, so that'll be next weekend's test for my plane.
As for the CG debate, I started at 5", and now I'm completely satisfied at 6.25". It'll harrier completely stable at this setting, waterfall tight, land at a crawl, and do the most shocking low altitude wall to waterfall. The more I moved my CG rearward, the less rudder coupling as well, another added bonus of the 6.25" setting from the book's 4-7/8". Great Planes really has a winner here.
Eric

U Can Do 3D
 

Hey Eric,

I've got pretty much the same setup as you, same engine etc. I've tried a 14x6, a 15x4W and now I'm about to try a 16x4W. My CG started at 4 7/8 and I'm currently at 5 7/8 and it's not quite enough to get a good hover or waterfalls. In hover it still falls out nose heavy. Waterfalls catch at 270o. So I'm moving the battery farther back. For you to get 6.25" where do you have the battery mounted? At 5 7/8 I'm about to formers back from the last former in the radio compartment (I cut a hole in the bottom of the fuse). One thing I do notice is it doesn't seem to matter if I move the CG back the stability of the plane doesn't change, no pitching or anything. Flys very stable!

David

Guys.....
 

I'm starting to dial in my CG as well. Also working on the mixes.....how do you guys have your's set up?

Thanks,

Pug

Stability
 

That's what I've found too. I started out with my 1800mah pack and receiver right on the rearmost former in the radio compartment, and then started adding weight to the tail. To get to 6.25", it took 3.25 ounces. This is where I really like it, so last night I put it back on the CG machine, removed the weight and marked where I wanted to cut a hatch and mount the battery. It is really about halfway between the stab and the ailerons.
For Waterfalls, mix in up spoileron with your down elevator and it'll tighten right up. Up Spoileron for Harrier as well will calm the rocking, that combined with the rearward CG will all but stop it.
Mine has gotten easier and easier to hover as the CG has moved back, but I do have 2 washers under the left side of the motor mount to get in some right thrust, and it could probably use 3 truthfully, but my cowl lines up so good I don't want to mess that up.

U Can Do 3D
 

What is everybody using for a spinner with all these lage wide blade props?

U Can Do 3D
 

I'm going to get a custom cut tru-turn for a 15x6 APC I plan on testing out in the next week or so. http://www.tru-turn.com They have a 2 1/4" which if you let them know what prop will go on it they can custom cut for a small fee if needed...they are well made and balanced!

eness76 - I'm going to do what you are with a hatch to begin testing moving the CG back...mine is at 5" now and flies and hovers great but I am curious to see what differences the move back around 6 will make.

I just finished up my review on the U-CAN-DO-3D. I have some pictures and videos. I also added 2 washers to obtain the factory recommended 2 degrees of right thrust. I have not seen a reason to add more though yet. I hope you all enjoy the review when it's posted in the next week! I worked hard on it to present it well through the internet medium.

Re: about 3 weeks in
 

That's encouraging... mine's at 4.75" now, I can't wait to get it back in the 6-6.25 range and fly it. I'm in the middle of moving the tank back to the CG, the former is clearanced and I just have to relocate the throttle servo and run a new control cable.

I'm using a 2.25" Dave Brown aluminum. I had to clearance the prop openings to fit the 16x4W prop, then rebalanced on a high point. I had to do some work to the adapter nut to get the spinner to fit, not too much of an effort really.

David

POWER
 

Will a Saito 91 4cycle have enough power to pull this plane from a hover?? :) Thanks John

U Can Do 3D
 

I can't believe you guys are still dabling with them little power plants on your UCD. Last week I changed my YS120NC out for a YS120SC, probably the strongest YS120 ever made, and Sunday at the field the UCD finally came alive. I have som 15-20 oz in the tail, including my battery, and it finally started flying somewhat tail happy. I bring it up, out of sight ha ha, throttle back, and it does a power of inverted flat spin ever so slowly. It does have a balistic vertical with this SC though, but man, all this power is FUN.
DKjens

U Can Do 3D
 

I think I'll go for the tru-turn.

U Can Do 3D
 

LOL nice engien chouce, same here, i have a saito 120 on mine, balanced pretty much were the kit calls, i think i am 5" back, flys great, hovers great, waterfalls super tight, flatspins, everythign
rockets out of hover, will give throttle then back off and bounces up and down like a pogo stick, tail slides for about 10 feet before it starts to fall out, even more if i steer it.
just my 3cents
thx
chris

UCD-3D
 

This plane sounds like fun. Now name some places to get a good price on one. Thanks John

U Can Do 3D
 

You will be lucky to find one. Tower is backordered until mid Nov.

UCD-3D
 

Has anyone tried a lightweight gasser on the UCD-3D? Would that combo work? May have to shorten nose and keep radio gear towards the back? Thanks John

U Can Do 3D
 

captinjohn.

I have my UCD 3d, and have yet to put a mount on the firewall for that very reason. I have toyed with 4 off the wall ideas for powerplants. The two main drawbacks I can see about gas would be the weight increase, and more importantly, vibration on the airframe. You would definately have to reinforce the firewall, and all the glue joints you can get to, as well as double up the former where the wing dowels slide into.

1. RCS 1.4 gas powered engine. Significantly heavier than a glow counterpart, but could fly for about a dollar a month on fuel (gas).

2. Homelite (or similar) 20-30 cc conversion with electronic ignition. The electronic ignition is a must to keep the weight down. 3ww-24 would make a great turn key engine, but its alot of $$$$$$$.

3. Totallly opposite end of the spectrum. .36 or .46 two stroke with a 1.5 to 1 belt drive unit. (Still tryin to figure out the mechanics of that for longevity and power.)

4. Using a DeWalt or other high quality drill motor, and go electric, with a belt drive. We have a harbor freight store here who has cordless hammer drills on sale, which might have enough cajones to be an option. I think it would be hillarious to use the stock batteries, charger and slip them in n out LOLOL.

Then again, we do have a swap meet next weekend, if I can come across a deal on a 100 or a 120, my decision will be made for me LOLOL.

Steve

engine choices
 

My reason for still messing with my 91 is that it's more then enough for the airplane for me. I've hovered it low on every prop I've tried and it very confidently pulls out, it will even walk down in a tail slide and confidently stop where I want it to, so I can't ask more out of it. Plus I don't need a hunk of weight in the rear to get the CG where I want it, but to each his own. I'm glad you all are having fun with 120s in it, it seems to accomidate a wide range of engine selections, which makes it fun for all of us, that's the beauty of that huge wing and light weight.
CaptinJohn,
Mine has an OS on it, but my brother has a Saito 91 and the power seems to be very close, and the Saito is a lighter motor so you probably wouldn't need as much tail weight as we did if you want to move it back behind spec. As I've never seen one in person with the Saito that's my best guess, but "Mecam" posted a video some time ago of his UCD with a Saito 91 and it looked like it had plenty to pull out of a hover.

My personal opinion is the 91s have plenty of power to do the maneuvers, but it's not going to be TOC power to weight ratio. I bought my 91 specifically for this project, and if I had it to do all over again, I would. I really like the combination, and my background is 21 years in RC with many of those competing in pattern, so it's not like I'm just coasting around the sky and the 91 is just getting by. Everybody is different though, on this project I didn't expect ballistic missle vertical performance, just some close in, low speed, 3d. I got my fill of the balistic performance when I used to have my Saito 180 on my Goldberg Ultimate!

U Can Do 3D
 

Glad to hear you are pleased with the OS 91 FS in this plane. Sounds like I will enjoy it as well. I just finished mine last night. I am hoping for 1st flight this weekend! :D

U Can Do 3D
 

Tower has a Tru turn 2 1/4" jet spinner cut-out for 120. It should fit the 15x6, but not the 16x4W. There are 3 left when I checked last night.

U Can Do 3D
 

With the 91 4 stroke, is 15x4W the best prop for 3D? Or is there a better prop for it?

props
 

I've been testing a bunch on mine, and my analogy is like with a car. I felt like the 15*4 was like a car spinning it's tires coming out of the hole, it felt like it was wasting some of it's power over revving that prop. The 16*4w was more like the car bogging out of the hole. But once it spun up, there was a lot of bite with that prop, it just doesn't transition quite fast enough. The 14*6 was actually pretty good, much to my suprise. They've all been pretty good, I'm just looking for the best of the bunch, the 15*6 is next. I really liked it on my friend's UCD.

Okay.....
 

I see that we have the engine and prop just about worked out......but how come no one wants to talk about how they are mixing out the tuck?????

Pug

U Can Do 3D
 

Gentleman - I've finished up the review in our RC Universe Magazine on the U-CAN-DO-3D. For those who have built it, are building it or are thinking of getting one I hope this review give you a feel for the whole 'U-CAN-DO-3D' experience!

I hope you all enjoy it!

http://www.rcuniverse.com/reviews.ph...ew&reviewid=44

Re: Okay.....
 

The tuck, as I think you mean it falls toward the gear when in knife edge, seems to happen more at certain speeds with me... anemly the faster I go, the more it "tucks"... However, the U3D will knife at about stall speed with my Saito 100 and a 14x8 prop and I hardly notice any falling away at all.

I'm pretty sure it's a combination of CG and aileron differential...

I think with such a long moment, the forward CG has more effect...

I plan on really experimenting/tweaking the settings when time allows...

If you're "in a hurry" just throw in some rudder>elevator mix and simply dial it out.