that sound right
but try it anyway
i hope i works out

i know it's not common to do this. but if the specification of the torque are higher then STD servos. Do you really think they will burn or brake if they used UNDER those torque numbers ?
when i look on the UCD ELE , it's not that big surface for one servo. (i'm talking on each half). yes on the glider i didn't have any issues of vibrations but i think the forces at times where much
higher then what it will ever be on a UCD.

using micro servo will save weight of 2 STD servos...

i'm not sure still debating here , i have STD servos ready to install (Hitec 545BB, Futaba 3001,Tower TS-69BB (from my Kangke Fun 50 - almost identical plane to the UCD46)
. but the Micro are more impressive in SPEED , TORQUE and WEIGHT.

most of this depends on how much throw you have
and how hard you fly
if you fly smooth then you should be alright

i'm trying to get as much throw as i can get using the Du-Bro long arms, and probably most of the time smooth but i don't want to worry about servo breaking if i will do some 3D.

which prop is recommended with OS 70 ?

apc 14x4w

In Colorado a 13X4W. A 91 at this elevation would use a 14x4w.

won't it be easier on the engine with the thiner air to swing a bigger prop ?
i understand that the engine got less power here , but the air resistant is less as well.
don't they cancel each other on the engine part ?

i never thought about that
in pitt my dads ucd with a 70 had a 14x4w

the new ucd im building right now for him has i 91 on that will swing a 15x4w poroop

There air density is extremely negligible. I'm a mechanical engineer thus I know all about fluid mechanics, thermodynamics, etc. The air density changes by a factor of less than 1%. This results in a great loss of oxygen content, and at my altitude of 7500 ft. my engines have a power loss of 25% with respect to sea level. Its absolutely disgusting, and that is why I have to really overpower planes.

-Matt

it's almost ready to fly , probably tomorrow maiden flight.

i got today at the hobby store 13x4W. W = 3D ? is it worth the extra (it's about $8 prop)

its about half the price of the 14x4w, so its perfect

Success ! went today relatively late , it was after 5pm already . so not much time was left for me to try it out.
fueled it , checked radio . throws on low rates are as the manual , high rate are as much as i can get.
CG a bit behind the recommended.

at start i the engine didn't fire up (OS70). the niddle was too closed.
opened it and the engine start right away.

took off , had to trim the AIL only few clicks to the left and the plane tracked like pattern plane. i was surprised how slow it can fly. i did few slow rolls and landed . landing was very easy with that slow speed that this plane can go.

i will program tonight the radio for more advance mixes . but bottom line i'm very happy with it. test flight was piece of cake .

power wise on the OS70 with 13x4 doesn't look too promising so far. but it may be out of tune, too early to know.

I think you'll find that the os70 is a bit underpowered to get the full potential out of the plane. I have th Saito 82 on mine and I wouldn;t call it overpowered by any stretch. Congrats on your flight!

i'm getting about 10k RPM with the 13x4W on 5% nitro. maybe the 14x4W will work after all with 10/15% nitro ...

Give it a shot and see how you like it. If it doesn't work out and you don't have to ream the prop too large I'll take it off your hands.

i had to take the OS70 out because of broken sping valve . so today me and my friend assembled it back with new springs.
earlier i balanced the prop as well. i was flying with it till now not balanced.

well the engine wont idle on the ground over 30 seconds.... it dies . but this is not why i'm posting now.(could be the springs are too new and tight ? need to re adjust the valves ?)
the real annoying thing now is the noise the plane does. i heard that in the past at our field with the same plane and Saito82.
i hear the wing vibrate or harmonics/resonance into the wing/covering. very annoying.

very weird , i didn't do anything except new springs to both valves ,and balanced the prop. anyone know this problem ?

it's loader then the engine sometimes !

Pretty common. Mine sounds like a drum every time I rev the engine. Sucks, but nothing you can do about it as far as I know.

yeah i figured it's pretty common. but i'm sure something can be done just because mine didn't do before.
maybe the way i installed the engine this time on the mount. too tight or too loose. i did installed the bolts and nuts opposite to previous time.
and i noticed that one of the shims touch the engine case. who knows ...maybe that transfer the engine vibration better now. maybe my engine vibrates more now because of different
valve clearances . maybe the covering got loose somewhere in the wing . i'm sure there is a reason for that. i refuse to accept this it was so much nicer before ...

I've had 4 of the 46 Do's and they've all sounded like that. Some not as bad as others but they all did. The reason is is that there is only 4 ribs in each side of the wing and the monokote drums in between them. You could try some saddle tape on the wing and see it that helps. [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXE102&P=7]Dubro saddle tape[/link]

Mine changes from day to day. One day it will sound like a snare drum then the next it is relatively quiet. I have tried heating the covering with a gun or an iron and it doesn't seem to make a difference with mine.

It gets peoples attention when I hover and provide my own drum roll. :-)

yeah i checked it again today. there is some relatively low RPM range when the drumming starts , anything below it or higher and it's fine.

Do you have any pics showing how you reinforced the firewall and LG?

hi i have been looking for some 3d planes and i really liked the ucd 46. the only problem that i have is that i am not sure if it will hover with a 55 ax since i am flying at 7000 feet above sea level. and if it can hover i wont have enough power to get the plane out of the hover. what engines do you recomend me in order to hover this plane? it can be a four or a two stroke. What props should i use?

the last thing is, the plane really needs a a high torq servo for rudder?

thanks

I doubt that the 46 will hover very well with a 55AX at 7000 ft. Most of all you won't have enough power to with it to be comfortable trying to pull out of a hover.
I've had 4 of the 46's and find the Saito 82 with a 14x4w APC prop to work the best. Maybe an OS 60 would work well on it, not sure.