engine for the u can do 3d .46

[barrett]

i was wondering if any canadian guys are playing with this bird. I know its not a precision f3a aricraft, but this is the closest catagory. Ive done quite alot of reading, and alot are finding that the CG and flight power is best with a saito .90 (or is it 91?), and a saito 100 for some a little higher above sea level flyers. also a lot were saying that a .61 2 stroker would work good. any opinions?

[can773]

Are you sure you are reading about the UCD 46?? There is also a UCD 60 which came out first and is probably what you have been reading about.

The powerplants you listed would work well on the larger size, but for the 46 size a YS 63, Saito 72, or the 50 size two strokes would probably be more suitable.

[barrett]

yup im sure that its the .46. both ucando's are weighing out tail heavy for the most part, alot of people are getting away with 1.2 4 stokes in the .60 size one.

my main concern is that i was comparing the saito 72 and the os 61, both have the exact same weight and the 2 stroke os has a little more power, so if the 70 size (20oz) motor is recomended for the .46, why do they say not to go past the .50, which weighs 14 oz, while the .60 weighs 20 oz.

i know the plane weighs out perfect or even still tail heavy with the saito 72, and i mean if i put the .50 in there, i would be neading to add weight in the form of lead, why not in the form of reserve power.

any opinions, or anyone with first hand?

[can773]

I was reading through RCU about this after I posted, I see what you mean. Some of the posters planes are getting awefully heavy over 6 lbs. If you can keep it around 5.25 and in balance than any of the 60-70 four strokes will pull it fine. The servos appear to be in the tail from pictures, if they are getting tailheavy planes and they have servos at the back then that is the problem. Move the servos up front and no more problems.

You would be better to attempt to keep it light than have a 6.5 lb model with a 60 in it. I am sure it can be done but I have yet to see one so maybe it cant.

I have a Flip3D that weighs up around 5.5 lbs with a YS63 on it (I live at 3600' asl) and it has no problems for power from any attitude.

[barrett]

i would like to keep the servos in the back, because if i moved them up, i would make them a pull/pull setup, and im too lazy to do that right now, ha. but i think im gonna buy myself a saito 72, see how she does. This plane is quite big i thought for a 40 size, and in my opinion is almost a 60's size plane, especialy with such a thick wing.

and yeah ive read everything on rcu about it, and you can see me (painly) asking questions over there about it, with not much luck on the 60 sizer.

im building this plane with all 3003's, so this should help the weight situation quite abit

[can773]

Too lazy for pull-pull, now that is lazy hehe :)

I put the servos as called for in the tail of my Flip (Futaba 9402's, not the lightest on the planet) and I really wish I hadn't. I am flying it on the tail heavy side and have an 1100 mah 4.8V pack right in the nose to keep it flyable :) After the Worlds is over I think I am going to get some of the new 9650's digitals (which are about 1 oz lighter each than the 9402's) then I can get rid of the wheelpants and put in a 720 NIMH pack, and I should be able to balance fine and lose about 1/4 pound in the process.

Put some smaller servos back there if you got em, might save you a headache later.

[barrett]

all i have for smaller servos are hs-81's, std. so i dont know how well they would hold up. actually i am really considering doing a pull pull on it now. would make up for my lack of servo quality, and hopefully prolong there lives.