Does any one have one of these planes from Great Planes
I pickup one yesterday and would like to know what motor to run in it
Thanks

It list a .91 for the top end power, BUT I wonder how much 3-d "U-CAN-DO" with a 7+ lb plane with a .91? Probably not as much as you think! I have a 6.5lb G.P. Giles 202 with a strong Saito .91, it will hang, and pull out REAL slow. I cant imagine what it would be like a pound heaver. I'm not saying you can't hover a U-CAN-DO-3D, with a .91, but you aint gona have a whole lot of clicks left to slap the tail around like you'll need to. It looks like a job for a strong 120 size engine to me. Lets face it, hovering is one of the backbone maneuvers for 3-ding. I would have to see one before I bought one.

Green

I am right there with you! I almost bought this plane till I saw how Big it was. I am sure a 91 will fly this plane and probably well but, I just don't think it will have the power to weight That I was looking for with a 91. Someone put a 120 in and report back please!

They say a 61 or 91 2 stroke. Or a 91 4 stroke. I think a good 91 2 stroke is going to have the power. In fact that is really what they recomend. I am putting a 91 MVVS in mine.

Someone needs to calibrate the scales at Great Planes. Every one of there planes comes out about 1/2 lb heavier than they list it. I wouldn't be surprised to see it tip the scales at close to 8 lbs. If it gets anywhere near 8 lbs, a .91 anything aint gona do it!(hover effectively, that is) Don't take my word for it though, just take the bait, or bolt on a 120. I like G.P, but there planes always come out heavier than they list, thats all. Someone buy one and let us know for crying out loud!!!!

i flew my 3D today it weighs 7.5 with a os 91 fx and a 6 volt pack it's going to have plenty of power even for hovering... going to be a good flyer ..has a lot of rudder authorithy

That is the difference between 7.5 and 8 lbs.

more importanly what is the wing loading for the u-can-do?

There is a thread started about this plane in sport and pattern. One guy put a YS 140 on it. Said it was way to much power and has trouble slowing down and if he did it again would use a YS 91. One guy put a 120 in his and said the instruction book is correct. The plane will not sit still on the runway and much more difficult to hover with. The instruction book says The OS 91FX
hovers almost as good as the OS 91 4 stroke but motor of choice is the OS 91 4 stroke

I have one on order and I am leaning towards the O.S. 108. The power to weight ratio is good on the engine and I think it would be perfect since mostly I am hearing a 91 2 stroke is not enough and a 120 is two much

What does everyone else think

for those that have them allready,..what is the ground clearance?,..i.e. how big a prop can you put on it without making new landing gear,.. and how does it fly on it's side?
I'm building a Funtana now for a 30 cell electric system,.. and this plane could probably do well on it with only 20 cells and lower gearing if it has enough clearance for an 18X10 prop. The Funtana will have a 20X11 on front that in testing is making about 17 lbs thrust. for the smaller "u-can-do-3D" , 20 cells and the smaller prop with less gearing would probably be right,.. at just over 10# thrust. If it flies on it's side well, it could be a future project.

gwright
I have one with a Saito 100 on it and I am using a 16X4 prop with 2 1/2 inchs from the bottom of the prop to the ground
I din't know if that will help

I am flying my new Ecstasy, which is a 7-1/2 lb. proto-type with a 90 ST, Mac Long Header and Tuned Pipe & an APC 15x4W prop. It has 1255 SQ. Inches of wing area that hovers just over 1/4 throttle. An OS91 FX should be great on this aircraft. I would question the 91 - 4C. With my personal taste, I think I'd go the 120 4C if I was going the 4C route. The 91 4C will fly it for sure, just not quite enough HP for my personal taste .
Kevin

Saw one fly this weekend with a brand new OS91 4 stroke (not broke in yet).

An acclomplished 3D flyer owned it. I flew it also. The OS91 4 stroke works for this plane.

The plane came out at 7 lbs 10 oz. with some fuel in the tank.

The airplane torque rolled, knife edged, waterfalled, and flat spinned. The owner touched the rudder on the grass also.

The airplane flys very well with the OS91 4 stroke. After watching it fly and flying it this weekend, I would question adding more power.

The owner watched a demo of the airplane fly at Chattanooga and it too was powered by the OS91 4 stroke.

Just my 2 cents. I thought exactly like everyone else concerning the potential lack of power of the OS 91 4 stroke until I saw one fly.

latch66

Thank You!
It's about time someone responded with some positive comments about this plane with an os 91 4 stroke up front! I just bought one and was so mixed up on which engine to use. I am now going by the book ( Great planes book) and using an OS 91 4 stroke. Anyone out there use an os 91 4 stroke and were not happy with it flight performance?

Latch66 - what prop did he us on his OS 91FS?

I'm doing a review on the U-CAN-DO-3D for the RCU Magazine and putting the OS 91FS up front. Once done I'll have lots of pictures in the review and video of this thing doing the 3D routine...you will be able to see right here what it can do. Shooting for November Issue which is about 40 days give or take.

A buddy of mine brought out his brand new UCD3D to the field today. My first thoughts were about how big this plane really is! He powered it with a YS 60 helicopter engine, but I don't know what size prop he used. We didn't weigh it, but I'm guessing 7 to 8 pounds.

He let me fly the UCD3D, and to be honest I had serious doubts that a 60 would be able to do much more than just fly it. But I was wrong! I was easily able to hover and torque roll, with enough reserve throttle to easily climb out. It had plenty of power for "3D flopping around the sky". Knife edge was good, but more power would probably make it better.

Overall, I was VERY impressed by what this plane is capable of doing! I've never flown anything like it before. It reminded me a lot of how the Cap 2x flys in G2......and I like the way that simulated Cap 2X flys! Considering what a 60 powered UCD3D was capable of doing, I would think that a lightweight 90 such as the OS 91FX or the ST 90 might be the ultimate power choice.....especially with a mousse can pipe.

The U-Can-do Latch66 is referring to is swinging a 15x6 APC. Its a great show to watch, but Hal Jennings is flying it. I am not sure that its a "fair" demo for us common folk. Hal can make a lot of stuff look like it flies great. Hal told me himself that it is plenty of power, but not enough "get out trouble" power for the inexperienced pilot.

Thanks jnjacksn,

You saved me from having to track down Hal because I could not remember the prop he was using.

the APC 15x6 is what the manual shows being used w/the OS 90FS so I was leaning towards that one anyway...now I know it's definitely the way to go. thanks for confirming!

Os 91 fs with 15*6 apc!

Now that we know what engine and prop. How about what servos, speed and torque?

U-CAN-DO-3D, OS91FS Pumped, but no servos yet.

ST 90, APC 15x4w.
Old Futaba S-131S on ailerons and rudder, S-131SH on elevators. 5 cell pack for more power and speed.

a person at my club has one with a saito 91, and it flier great. it will hover and do all 3D. He says anything above a 100(if you get that) is too much!!!!