My U Can Do just started the glitch thing on landing approach. I think mine is coming from the wheel pants. The little screws are loose. I lost a landing gear screw also this weekend. My thoughts are it was one of the two. Seems to glitch about 50' away and about 15' high on approach. Mark pirate:

My turbine flamed out twice today! What's up with that? Darn U-Can-Do!

WARNING!

Checking the needle setting on my Saito 100 after 2 flights today. Has less then 20 on it. Opened to full throttle, about to tach it, and it RIPPED the firewall off.

That COULD of hurt, but I was lucky.

Close inspection of the firewall, I can hardly believe this did not happen sooner. It came off CLEAN. There were only o few spots where the glue was actually holding.

I would be pouring the zap in, and running it arround that firewall. I know there are hundreds of them out there, and I can't believe mine is the only one to have this happen, but it simply is not worth the risk!

Hmmmmmm......
http://www.greatplanes.com/techsupport/gpma1270tech.pdf

the saito 100 is the same power as the .91 ys

My saito 100 was just nice breaking in. Other then wide open throttle to set the needle, I barely even flew it open throttle, except for up lines, and during easy manuevers.

Others have way over powered there U-Can-Do's, and the Saito 100 seems tobe THE motor of choice.

"Hmmmmmm......" Tomapowa, I do not understand the reason for the post.

Everyone that purchased the U Can Do had a copy of that sheet in the box. (except for early kits)

The warning refers to overpowering the airframe to achieve faster airspeed. In my case the Ys140 was installed for hover pullout power while learning to hover.

The Saito 100 may or may not have been the cause of the firewall separation. Many factors could be linked to the failure. Hard landing or two, Prop not balanced just right, Lack of glue, harmonics, to name a few. One of these or a combination of these (even worse) may have been a factor.

Any of us that overpower this plane gain faster airspeed should expect failures related to higher airspeeds. I KNOW that my plane will come apart if I do not use throttle management to limit airspeed.

On page 26 of the manual it refers to the OS120. The reasons listed for not running that combination are 1. Increased tail weight. 2. Would not sit still on the runway. 3. Poor throttle resolution in a hover.

The manual in the same paragraph states; "I do not recommend a 120 4 stroke or LARGER engine IF performance aerobatics are desired." Says nothing about keeping the firewall on the plane.

http://www.greatplanes.com/manuals/gpma1269-manual.pdf

Moving the RX battery to the tail kept me from adding extra weight and put the CG @ 4 7/8". Also the YS140 has offered excellent throttle resolution at any desired setting.

I think his post was meant to help others with this airframe.

The .60 size UCD has a history of firewall problems,along with the landing gear block.The problem is a lack of common sense on the manufacturer, you cannot expect hot glue to hold on the firewall regardless of the engine size.I have one with a YS 91 which is in the range and it had no crashes etc. but it pulled off anyway.This is a manufacturing problem period.

I am planning to reinforce my firewall. Does anyone have pics of a separated firewall and the fuse front end that show how they interlock together ? It will help in deciding the best way to strengthen it. Thanks..............

Look for a post called firewall warning.It has a picture of one in it.

Hi Doc, did a search within this thread under "firewall" and "warning" but no pics turned out. You sure 'bout this ? Man, I'm drooling for this pic.................

Here was my firewall experience: http://www.rcuniverse.com/showthread...221#post499708

From what I remember of the firewall, just the usual tab style interlocking. When mine was off, I used 1/2" tri stock to beef it up and at the same time, beefed up the LG mount area while it was easy to get to.

Dalee

http://www.rcuniverse.com/showthread...rewall+warning




Here you go Rajul..

This is not the first time somebody had a firewall problem with an ARF. There are also plenty of people who go against the manufacture's explicit warning about not exceeding the recommended engine size. Is there a connection here, I wonder...

My question is: did anyone have the firewall fail with an engine in the recommended range?

See post #1235.If you saw it for yourself you would not believe how poorly it is done.Not only hot glue but 1/4" tri-stock.I do not think a plane from GP should be this way.I have owned several GP
airplanes and never had one built this poor.

Where would we be, if we all followed the manufacturers warnings?
Good think Chuck Yeager didn't follow the Norm, would we all have Wright Fliers. Or would we even have the the Wright Flier?

The U Can Do as with all 3D/Unlimited aerobatic class aircraft,push the edge of the envelope. And how would we know what the edge was unless someone was always pushing it?

I think we are all learning from each other here.

First off, this is a model purposely built to be extremely lightweight for hovering and 3D manuvres. It should be understood by anyone buying this ARF that it is NOT built like a tank.

Secondly, I just got mine last night, and looking at it, it's not much larger than my 60-size trainer and sport planes. I've been guilty of overpowering too - most recently a G-23 on a GP Spacewalker - but I think I'm just gonna put a .75 2stroke on this one.

Thirdly, the overall construction is pretty good compared to the many ARFs I've come across in recent years. Not the best I've seen, but certainly nowhere near as bad as some of you are portraying.

Fourthly, I don't see hot glue anywhere visible in the frame work. I do see yellow aliphatic resin in many places and epoxy on some spots. Don't jump on this "hot glue" cry so quickly. Have you put a soldering iron to the glue? That's a sure fire way of telling whether it's hot-melt glue or not.

Finally, some of you have far too high an expectation for these ARFs. It sounds like you mortgage your house to pay for these little ARFs. For $189 (I won't tell you how much I paid for mine - it's obscene ), I think a little bit of extra work to get it right is perfectly acceptable. Every single ARF I've assembled has been modified and reinforced to one degree or another. To me, it's actually FUN to modify my ARFs.

Let's just get away from the CA fumes, go outside, take a deep breath, and CALM DOWN. Take just a couple more hours to put together that next ARF. You'll feel a whole lot better. Really.

Volfy,
I completely agree with you. I'm amazed that people will buy this particular ARF and put ridiculously large, over powering engines and servos in them. If you want to go overboard and be absolutely confident about the construction,... then get something else and build it yourself.

Hey Volfy

I agree, sort of, but I think we have a right to get decent construction for our money. I spent almost $300.00 for an OV-10 Bronco ARF plus two .32 OS engines and servos and the thing required major (really major) reworking. The model wasn't airworthy by any stretch of imagination. I am so disappointed in the model that I haven't flown it yet, and I finished it last year. Yes, I have written to anyone who might care, and some who won't. I may just eventually run it through my bench saw, since I have 19 other planes that I am happy with.
If anyone is interested in the .25 size Bronco, please ask for a copy of my letter, listing the items that needed correcting.
I have enjoyed the discussions re the U CAN DO 3D. I certainly won't buy one.

Hey Doc, thanks for the link. Yep, saw the pic and it should help me figure out a reinforcement method. It definitely needs it. Many have had no problems without any reinforcement and many have had problems with the stock firewall. As Volfy said, its fun to analyse and do some mods, and that's part of r/c ain't it ? Actually, I am doing the reinforcements for SAFETY........

As far as what kind of glue it was it was white and it came off without pulling any wood loose. It is a safety issue as well as a crash concern.It is however a fun airplane for the money but I am saying I expected more from GP.

I don't mean to say that mods and reinforcements should be considered a fact of life with ARFs. I just think that the UCD is quite a lot of plane for $189.

GP does listen to us buyers too. The box my UCD came in has stiffening plywood sheets secured to the sides. My guess is that they were put in later as a fix to address shipping damage issues I read about.

BTW, I tried pulling the firewall loose with all my might tonight, and nothing happened. Okay, I'm no Arnold, but I would think what I can muster is a heck of a lot more than even the most stout engine you could possibly mount on the UCD. Vibration in time could work the firewall loose, but that's true with any model. May be some of you just got lemons, unfortunately.

You should try some anabolic steroids then ! LOL !

I put in 9 1/8 dowel pins around the perimeter of the firewall on mine with a ys-120 and even after 50 flights still no problems. It took about 5 minutes to complete the modification. I also pinned the landing gear. The only problem so far has been a torn off elevator counterbalance when dipping the tail in the lake at my buddys farm. A little glue and some packing tape and we were back in buisness. Now I know why it was a good idea for the bolt on horizontal stab assembly.

Sounds like a good idea with the hardwood dowels. Any pics of the firewall and landing gear after your mod ?

I was also curious about the bolt on horiz stab ? Is there any pic of this in this thread or elsewhere ? Thanks.........