I always tune my engine with full tank, you have a good point there tho. but my question is, will an overheating engine die like how it did in my case?


thanks

Well, there are many variables that can kill an engine like that. You have to get your tuning correct first. How far is your IB regulator from the carb? The nearer the better

my regulator is pretty damn close to the carb (~3") I think it just overheated, which was caused by hot weather+not rich enough to cool engine temps down a bit. oh well, I am done with glow engines, I just got myself my dream engine/plane (DA 50/Yak).

thanks for your help Rajul.

After practicing some more this weekend I think I figured out what the plane needs to stay low. Part of my problem has been a faulty Cline,but I have that fixed now. I didnt get very low this weekend,very windy, at least I didnt do any Dork-Rolls!

I broke mine in half(one just behind the wing,other just infront of stab)twice & they both flew again. I used carbon fiber tubes overlapping the break by several inches each way,had to channel out some to get them embedded,then use Pro-Bond Poly glue after tack gluing with CA. Didnt add much weight and they are stronger now. The Do is very weak behind the wing-only balsa there.

Man,was it awesome out there last night. Dead calm,I got out late,started flying about 6PM but it was worth it,I did more in 2 hrs than the whole weekend 0f 20-35MPH wind. I need more of that,I could practice without any hits,the Do did everything I asked of it. I got some things sorted out,it will do inverted harrier,man is it a different feel,needs a whole lot of opposite rudder,way less elev,way less throttle,its like a different plane. Did some T/r down to about 8ft now & getting confident,I transitioned from harrier to hover with little climb out,I was on the throttle too much before,now I just slowly,gradually ratchet it up,only one click at a time till its vertical. Its easier when no wind to knock it around. I felt I had a 40% in my hands,does the Giant Do feel any smoother in the wind?

It was awesome flying here in NJ yesterday, and today is more of the same. Sounds like you are progressing well. Slowly bringing up the throttle or burping the throttle a couple of times are good ways to transition to a hover from a harrier without gaining much altitude. Spoilerons fight the transition but I use 50% to harrier the UCD. Inverted harriers are MUCH easier than upright on EVERY plane I've flown, once you have the skills. Inverted harriers have virtually no wing rock and transitioning to a hover is MUCH easier, just push the elevator and slowly increase the throttle. Looks really cool and is actually much easier to do once you can harrier inverted.

I'm taking my 50cc vision out tonight, if it doesn't rain. Winds look light.

Have fun.

I've heard that, and have seen a friend harrier inverted well a plane he doesnt harrier upright very good,must be me again.,but I dont give up easily. The theory sounds good,fin&stab in clean air,but the Do becomes a high winger inverted,that should make it more stable too,sometimes its better to just fly it than think about it.

I have a U Can Do 60 sitting around in the box waiting to be built. And, I have a Saito 82 looking for a home. Will this 4-Stroke work in this plane? I am not looking for extreme 3D performance...
Thank you all for your thoughts on this!
Rob

Rob, The 82 will work but I think you'll be disappointed with the performance. I have an 82 in my 46 and it does good in there but I think you'll need a YS 110 or a 125 Saito to really appreciated the 60.

Will I be disappointed in the 3D performance of the plane... For example in hovering?
I guess I was afraid to go to a larger engine as the instruction manual has an addendum in it with a warning to not use anything larger than a .91 FS.

Hovering requires the most power/weight and is the most stress on an engine,the Sa82 wont cut it for that,but will fly the plane and do anything that doesnt require more thrust than the weight of the plane,the 60 UCD comes in somewhere between 7.5 to 8.5 lbs. The engine size on the instructions is best if this is only your second or third plane,if you have a lot of building and flying experience you could opt for a larger engine but might have to make some modifications for the airframe to hold up to extra stress.

Hello first post here,
I have a UCD3d with an OS 4 stroke 91 pumped. I have flown twice with a 15*6 prop, and it seems very underpowered. I am flying in CUernavaca Mexico, 3000ft Elevation with temperatures on the 90's. I just got a Saito 4 stroke 150, and JR8611a servos. From your experience is this engine too much for this airplane? Thank You. And also would anybody help me program my radio Futaba 9 CAPS?
Alex

just got my first ucd any quick building tips problem areas? using .46nt for now and ds811 servos ..

Hello and welcome to the thread. Are you talking about a 46 U Can Do that you have the 91 in? If so the 91 should do okay in it but at 3000 FT you probably will have to use 30% nitro to have some power. The Saito 150 is way too much engine for the 46, I don't know if it's too much for the 60 size but it sounds like it is.
For programing the 9 Cap radio I would recommend this book.........[link]http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXFJZ7&P=ML[/link]

Hello, welcome to the U Can Do thread. Are you talking about the Evo 46? If so you'll be able to get the plane off the ground but will probably be very underwhelmed with the power of the Evo 46. The problem with a 46 size engine is that you'll end up with too small of a prop to throw too little of air over the control surface. For some serious 3D you'll need a larger 2 stroke or 4 stroke. These planes fly very slow and you want a lot of wind going over it in the slower speeds.
For building tips, you'll need to beef up the landing gear area. Some of the guys on here have "pinned" it to make it stronger. I'm sure they'll chime in here to write how they did it. Also, you'll find that some on here have put tail wires on it to strengthen the tail feathers.

Thank you guys! The Airplane is a Ucan do 60 to 91 size, and the engine I put on was a 4 stroke os 91 surpass. I am going to try with a Saito 150 as the 91 is underpowered. Anybody has done this? I am worried about the warning not to go any higher than 91. Should I reinforce the firewall area? if so how can I do that?.
Thank you all
Alex

It will take the weight of that engine,I had a Moki 1.35 which is near the same weight as the SA 150,mine was 8.5 pounds and flew quite well. I did add tri stock to the firewall,landing gear formers. In that heat,you might want to take the cowl off at least for break in,fly only in early AM or late PM. You should have plenty of power to hover & pull out.

The evenings have been awesome for 3-D, on Sat, I tried ailevator mix on for the first time to do 3-D, I seemed to have a bit more roll correction authority while in a harrier, everything else seemed about the same. It does make straight line rolls better, a little more axial. I did some walls so low the tail wheel smacked the ground as it rotated,the hover started only a few feet up,I got out after only a couple torque rolls,got a little shaky on that one but at that height,how bad could it go in?

Went out last night,I love evening when the winds are light,the Do is best in light winds,you can really get DOD. The engine doesnt transition well when its 85 or higher,even took the cowl off,same thing while TR'ing. At about 7:30 to 8:30,it ran perfect. I found out that ailevator hurts the rolling harriers,it helps snaps & rolls,and doesnt hurt the harriers at all. I wish it was on a switch. The Do is definately not a real good windy day plane,especially in 3-D mode,but every week I get a little lower in hovers/TR's,the rolling harriers are very slow and easy to keep up with,elevator & harriers are getting rediculous easy,land & take off,turn around right in front of me,pull to hover so slow,it looks like a 40%-all possible in light wind. I need to stop flying & finish the Giles(it should handle wind better)but it gets better each time out,I just dont think I'll ever want to fly the Do on those nasty,gusty days again. I'm gonna hear it from my flying buddies about that: (wind pu$$y!)

HI Guys,
Got a bit late into this thread so I dont know whats been said...Anyway here are my thoughts on the UCD 60.

Building: Dump all the hardware and upgrade it for 3 mm (thats 4-40 FOR ALL OUR AMERICAN FRIENDS :-) ). I mounted the motor sideways (OS91FX 2st), as the tank looks way too high to run a 2st inverted, mounting it sideways brings it about 1/4" below the needle valve on the OS which is OK.

I run 3305 futaba servos on rudder and 3010 every where else..all @ 4.8v

The plane balanced perfectly (5" from LE) with the battery above the fuel tank and the extra weight of the upgraded HW.

Flying:

I have about 4 deg right thrust on the motor and it still needs a little right aileron to hover, but makes torque rolls easier!

I flew this thing last wekend and WOW, makes you look like a real expert. Hovers almost hands off, Elevators are alot easier inverted, Blenders are OK but not as flat as I'd like, but I've only flown this thing 4 times! cant wait for this weekend. I'd guess at this stage I feel its not as capable as my funtana; but still GREAT FUN!!!

One final note on the engine...the os 91fx (I'm at about 200 ft above sea level here) hovers at about 2/3 throttle with 10% nitro on 15 x 6 APC..which is ok, but doesnt really give you a quick getaway when you get in trouble. I would suggest a saito 1.20 or OS 1.08 may be better choices......I have a moki 1.35 doing nothing at the moment.....but that would be a bit too much weight I reckon..

Anyway if you reading this thread and are still unsure if you want to buy a UCD.....its a bit of a no brainer....BUY ONE! A genuine rc bargain...

PS: for those UK chaps, buy some imperial allen keys as the kit hasnt been Europeanised yet!!

Welcome to the Do club,its a bit clumsy for some things but it has its place IMO,good plane to learn TR/hovers and elevators/harriers are possible,but it might take some modifications which are well covered in this thread if you feel like reading. Extremely slow, very high alph KE is what I like most,you do get something in return for that goofy looking fuse. By the way,you need more power--OS 1.08 minimum,even the Moki 1.35 will work on a Do,I've been there,maybe YS110 or Saito 125 is the best power/weight.

I flew the do yesterday, with this Saito 150 and it flew great! Lots of power for hovers and vertical climbs. Motor is still breaking in, so ill update later. I put the rj8611a servos. very fast and powerful, the airplane tracks very good.
Thank you all

I'm going to put a little life back into this thread for a short moment by asking this, I have a Saito 100 in my Do, It is brand new has 2 tanks ran through for break in procedures. The question I have is I picked up a gallon of Cool Power 30% today to try out its performance in this plane/engine combo, do I need to run a few more tanks 0f 15% in this engine before I switch to 30%? I don't want to fry this engine just yet I know that this question probably belongs in the engine forum but I thought since I got the idea from this thread then someone here could maybe help me out out.

Thanks

I always run 30% in my Saitos and YSs. I even run it for break in. You will be fine. Just run it a bit rich at first. The Saitos need to be leaned down quite a bit on the low end. Even during early running.

You'll be fine to run the 30%. Any you won't believe how much better your engine will run. Not only more power but better transition and idle too.

Thanks
Barry