I double checked the prop, it is a 10 x 8,,,MAJOR oops

Hobby_man

got any pictures of the kevlar set-up?? Can you post them??

Here you go hobby_man. You can also see the triangle stock.

Another thing to think about - I used 4-40 rod to start out with, and I bent them. The carbon rods won't bend or break, might help prevent flutter.

That prop size set off a big alarm!

For a .51 I'd try a 12x4 or 12.25x3.75.

The picture of your handy work looks great, Thanks.

Did you make your rods or buy them somewhere??

Actually they're not rods, it's kevlar string. Will not stretch, and pretty strong. It will fray from the vibration though, so I put a drop of CA on the kevlar where it loops through the eyelets.

Everything needed to do what I did comes in Sullivan's flying wire kit. I don't know the part number. The kit was 16 bucks at my LHS. It also includes steel wire, but I didn't feel like putting a potential source of interference on the tail.

Hello Everybody i want to get a U CAN DO .46, and put a 2 stroke in it.......does anybody have a good recommendation on what size two stroke engine i should put in there, big enough to pull it out of a hover at a decent speed, but small enough so that i don't have to modify any engine firewall structure..... thanks

i have the TT pro .61 w 13x4 prop. it fits in the stock motor mount. the macs muffler would probly be better than the stock one but im just using the stock. i like this combo but i haveent flown any others to compare it to.

Got a ucando 46..from what I hear, and what I saw, it doesn't take too hard a landing for the landing gear to rip out, so I strenghtened inside area, where landing gear bolts come thru fuse floor, with hard balsa and epoxy....so far o.k....but my other problem is that I'm having a hard time adjusting low end...I installed a Magnum XLS 52 upside down to preserve the cowl from getting cut up too much...carb. is now 1/2 inch below tank...after breaking in per instructions, I'm now told to do this: fill fuel tank while pick up tube to carb. is pinched, then remove pincher only when ready to fire it up...upon start -up adjust high end, then go to low end and pinch carb. tube again.....if engine stops abruptly, idle needle too lean.....if engine doesn't or sputters, idle needle too rich....I haven't been able to discern the difference yet....in 5-6 flights, all were dead-stick landings...if I don't get atop this problem, sooner than later, I won't be so lucky as to land it in one piece....is there a more understandable way of adjusting low end, anybody out there?????????

Im selling my UCD3D if anyones interested. http://www.rcuniverse.com/market/item.cfm?itemId=44809.

jerry jake i have tt.61 pro on mine and it likes to be a litle on the lean side but not too much, when i unn up to full then ease back to idle it will slowly creap up more rpms.but if i pick the nose up while idling if it revs faster then starts to die its too lean. its probly something to do w/the tight cowl.

The carb is below the fuel tank, so fuel siphens into the carb aon it own. I added an inline fuel filter and this helped. I then made my line from the tank to the carb go below the engine mount with a large loop and up and over the engine mount wit a small loop and this is where the filter is and then to the carb. The carb no longer siphens fuel on its own.

Hobby_man

I put a super tiger 51 ring in mine. It is upside down, this causes a fuel siphoning problem, that can be fixed.

Hobby_man

Got a problem with my UCD46.
Running an OS Surpass 91 FS with a 15x4W prop
Pretty well balanced out however i am starting to move the battery back to get the CG more aft.
Problem is in level flight i require about 3 degree up elavator to maintain altitude, this is at quarter to half throttle so it is not sinking. Thought it was down thrust that was needed, added a few washers behind the engine but this did not do anything.

Any thoughts, great plane but clueless at the mo.

where is your CG now? Are you sure that the ailerons are centered at nuetral? what does it do inverted?

Ailerons are centered at neutral and in line with the stab, 0 incidence, inverted requires some down elevator to keep it level, will get the wing on later and verify c of g.

Squid1

If you move the CG aft to a point that you need for inverted flight no down elevator or better the plane is climbing slightly inverted with sticks neutral, your CG is right for 3D.

Chuck

If you need up elevator for level flight you have too much down thrust.
Try this:
Trimm it for level flight at half throttle not to get too fast because of possible structural damage. Throttle back to idle. If the plane climbs, too much downthrust because you had to trim up under power and vice versa.

Chuck

good call chuck. i didnt know how to check the thrust.

Thanks for that, hopefully the weather will clear up over here sometime soon and will get some time to try it out, will remove the downthrust in the mean time that i have put in there, while we are at it what is a good way of checking right thrust.
Cheers
Squid1

Questions I had about my upsidedown engine that put the carb. 1/2 inch below fuel tank are now moot as on it's 8th flight, my u-can-do lost the elevator and , of course crashed...two things I will do different on the next one....(1) ca both sides of hinges at the same time...I did it by applying ca one side at a time and that was wrong , I was told....Hinges swell when ca is applied and the WHOLE hinge absorbs the ca therefore the one side that's inthe wood swells, so all is o.k.....when one applies ca to the other side after sliding it in the wood, that part of the hinge has already swelled when hinge was inserted in the first side, so hinge is not properly attached to the wood because it didn't swell enough..it sounds logical to me...does anyone disagree with that?? When I picked up the pieces, I noted that the hinges were still in place on the stab side and that's the side that I applied ca to first...(2)...I was advised to cut away a small amount of the covering to expose the hinge slit, drill a hole in center, then apply ca with those little squeeze tubes and put the small nozzle into the hole, then squeeze to be sure the ca goes where it's suppose to go to do it's job...that also sounds logical to me...if I live long enough I may be able to do all these little things that are so important and be able to go thru a season without a crash........that would be nice!!!!

never heard of that it wicks ca but i didn't know they enlarged at all. sounds like you didn't use enough ca how many drops did you use. what prop how much power did you use when it blew the tail off.

Cutting the covering around the hinge slot is a very good idea. I always do it. I think the CA can have a tendency to wick around the outside of the slot onto the covering if you don't do it. I myself haven't ever drilled a hole in the center of the slot, but it makes sense and probably does help.

The UCD intructions tell you to remove a small of film away from the hinge slot and drill the hole, so far so good with mine

OK squid1, here we go:

It takes some time to do the flightcheck for right thrust.

First all controlsurfaces need to be straight and zeroed especially the rudder. Fly the plane under power straight up vertical. If you have unlimited power use less than full throttle. You want to have the plane to stop the upward movement after some way up.
It's not that important in the beginning in what direction the plane is falling with zero speed. You want to check the upline. With still upward vector, if the plane is turning right - too much right thrust, if its turning to the left - too less right thrust.

Important: The vertical stab has to be glued in straight, rudder trim center and you checked that the weight distribution around the longitudinal axis is even. To check this on the bench, support the rudder, lift the plane at the spinner until the maingear is off the bench. The wings should stay level. If one wing is dropping add lead to the other wing until OK.

I can tell you, you need a lot of uplines because wind is always a factor. I check this in the morning at our field when there is no wind whatsoever and nobody around. It's kinda boring also for the clubfellows.

Chuck

Lifting the airplane by the spinner is not the correct way to check lateral balance, as the crankshaft centerline isn't in line with the fuselage.

You need to find a spot on top of the fuse that is dead center, and lift there.

Another way to check right/left thrust is to pull into a hover and see how much rudder input you're having to give. Mine always went left(I was constantly having to input moderate right rudder to keep it pointed up), so I added right thrust to the engine till it didn't want to go the same way every time.