RE: U Can Do 60
 

Deal me in, I'm back in the game. First a little history. This is a compilation of past UCDs. Rudder and tail wheel from #1. Wing, hor. stab. & elv. from #2 Canopy and landing gear from #3. New fuse, new cowl. Heres the list of goodies. JR-XP8103 TX, JR-R945 PCM duel conv. RX, 527 standard on throttle, DS811s on ail. & elv. DS8231 on rudder. 4/40 rods all round w/ swivel ball links. 5 cell 1700 mih NiCad. Saito 100 (old faithfull) swinging a 16/4 APC prop. The prop is analy balanced (hours) and yes.....I balanced the true turn spinner as well. You would be suprised as to how much they are off balance. "Dubro" pinned hinges. Stock composit engine mount on "Ernst" thrust plates. 3 degrees to start and I'm leaving the cowl off until the thrust is dialed in including up/down thrust if needed. Tank on the CG (5 5/8) with a "Cline" regulator. Laterally balanced. Will post the weight when time permits.

RE: U Can Do 60
 

And here it is.........not bad for a frankenshtien. Joe

RE: U Can Do 60
 

May I ask what you did to do that......would it be like balancing a tire...and just put weights where they are needed....or how did you do it??........

For a plane with as many parts that you have, it looks very great.....

RE: U Can Do 60
 

Mike, to balance the spinner I remove weight. Carefully, do to their pricey nature. I started with an old back plate to experiment first. You can dremmel or drill. On the prop balancer you do the back plate first. I chose to drill a small hole, 1/16" on the heavy side, then enlarged it until it was close. I finished it off with a light shave with the dremmel. When you are happy with the balance on the back plate, which is critical because if the back plate is not balanced then you are wasting your time with the spinner. Next put the spinner and backplate together on the balancer and finish up by shaving the heavy side of the spinner by removing material from the inside of the spinner cone. When properly balanced the back plate and spinner cone do not have to align in any sequence. Regardless of how it is assembled it is balanced. Now this comes into play more so on large diameter spinners. Mine is only 2 1/4 but was out af balance. Its not for everyone and I'm sure to some it doesn't make a difference since its so close to the center. Joe

RE: U Can Do 60
 

I had my UCD out for the first time this year today and ran into a problem. Went through a pretty thorough preflight check and felt pretty good about putting it in the air. Fueled up the plane and ran the motor pretty hard on the ground and it seeemed OK. Took off into the wind and set her sailing. Flew for about 5 minutes and pulled into a hover. Lucky I was well off the ground. The engine died and I had to dead stick it in a pretty voilent wind. Damn near ruined it trying to get it back to the runway, but ended up sitting it down. Landing was a little hard, but I wasn't too worried about it. When I went over to retreive the plane it was very oily with fuel all over it. I After I noticed that fuel was dripping out of the front of the plane! Ouch, I pulled the wing off and tried to diagnise what happened to the tank. Turns out the rubber stopper came out of the tank. Like3 I sid I did a pretty thorough pre flight, but it didn't include inspecting the tank setup. My tank is a pain in the ass to assess in the UCD so I didn't even think about looking at it.

Heres the fun part, I'm still trying to figure out what exactly happened. At first I thought maybe the stopper came out when I landed considering it was kinda hard, but if that was the case I would not have had the fuel all over the outside of my plane. But on the other hand, if the stopper came out in mid flight then why is there fuel all over the outside of the plane? There is some fuel that spilled inside the plane, but only behind the firewall. There is no fuel in the cabin or on the throttle servo [sm=confused.gif]. My tank is actually situated about 1/2 of the way back toward CG.

I'm using a cline regulator and Saito 100 and I'm wondering if there is possibly something wrong with my cline. For example if the muffler pressurized the tank and the regulator was broke then maybe the pressure built up enough to push the stopper out of the tank. The check valve would've prevented the pressure from escaping causing it to reach the critical point? Who knows. The stock UCD tank still appears to be in good shape at first glance.

I may try putting the thing back together without the cline and seeing if I can get it running well without one. I'm also going to make sure I put thread lock on the stopper screw. :)

I don't know exactly how much fuel was soaked up by the plane, but it doesn't look like a ton. I've heard there is some type of spray I can get form Wal Mart that will help with fuel soasked balsa. Anyone know the name of this?

RE: U Can Do 60
 

Considering the pressure the Cline can put on a tank it's not surprising that you have as much of a mess as you describe. You said the stopper came out of the tank. Did the stopper come all of the way out of just loosen up in the neck? If the stopper came all the way out I would bet that the result would be very much like popping the top on a shook up, warm soda can. All the pressure in the tank attempting to escape all at once in an instant, carrying the fluid out with it, makes a pretty big mess when it happens. I would bet that a lot of that fuel escaped out of the tank neck hole in the firewall and made it to the exterior of the plane causing the mess you described.

I opted to use a Sullivan stopper on mine, the plastic disc's and sheet metal screw are far less likely to loosen up over time and with vibration. I also think that the rubber GP is using for the stoppers in their ARF tanks is prone to shrinkage with time, resulting in the leaks and other problems many of us have experienced.

I'm not sure about the spray your talking about but a trick I have used very successfully is simple floor dri compound, you know it as the stuff mechanics pour on the oily spot on the floor, it is NOT kitty litter BTW. Whenever I have a tank leak in the nose of a plane I just pull it out and fill the nose up with the floor dri and stand it in the corner for a couple of days. The compound is VERY adsorbent and will literally pull ALL but the minutest amount of oil out of the wood. The only drawback to using the stuff is that it takes time to do it's job so patience is a virtue when using this method. You can get the real stuff at most auto stores and it's usually pretty inexpensive.

RE: U Can Do 60
 

My tank sat empty since early December. One of my last projects on the plane which I accomplished just last week was the fuel set up. When I went to remove the stopper I did notice that the screw did not need the torque that I expected to remove it. Seems like the stopper could have shrunk a bit from being dry for an extended period. Took the UCD for its maiden today after our spring clean up at the field. The wind was relentless. No way with this kite. Joe

RE: U Can Do 60
 

After several months of flying my UCD, the stopper on my tank came loose as well. I noticed fuel dripping out the bottom of the plane as I was fueling it up.
K2R spot remover is the spray if you can find it. It has been banned in some states by state level EPAs. I can't get it in Indiana but I have ordered it online. It is the best for this application. Spray it on and ley dry an hour or so. do this a couple times and your good to go. Monokote will stick to treated areas where other oil drying methods require some kind of sealer to get monokote to stick.
Good Luck,,,basmntdweller

RE: U Can Do 60
 

My story is similar... Stopper started leaking in a hover, engine didnt quit, but fuel leaked all over the receiver, basically flooded the airplane. The radio went haywire, and luckily, dried out seconds before imact and I was able to recover - literally inches from the ground. Receiver is toast, worked only long enough to land - now its being looked at at Horizon. I've put in a new tank, on the CG, waiting for receiver to return.....

RE: U Can Do 60
 

This all got me to thinking....

Years ago when everyone put their rec batteries under the tank in the nose it was standard prctice to put the battery in a plastic bag, just in case the tank leaked. It's beginning to look like a good idea once again, only this time bagging the rec would be a good idea as well.

RE: U Can Do 60
 

Thanks to everyone for the comments and the recomendations. The stopper was completely out of the tank so your theory on it popping out makes sense. I think I will try disassembling the cline and having a look. Although I really don't know what I'd be looking for to indicate weather it was bad or not. I will also probably try running the Saito 100 setup without a cline to see if it works OK. I originally got the cline when my engine was brand new and hardly broke in. I bought it in response to several posts early on in this thread telling about problems with the elevated gas tank. It can't hurt to try it.

I've never heard of K2R spot remover, but I'l look for it next time I'm at the store. I live in WV so I'm not sure weather it's illegal or not. If I can't find it I'll try the dry compund that shogun was talking about. I'm sure it's easy to find. I'm not really sure how much fuel is soaked in the wood. It doesn't look like much, but the foam I had the tank wrapped in was really wet. In fact it seemed like it was kind of absorbant in a way so maybe the foam soaked up a bunch of the fuel. I think ost of the fuel ended up on the outside of my plane. It was a mess :)

RE: U Can Do 60
 

I am also completing my UCD 60. I have a Cline regulator as well, but will try running the Saito 91 GK first without it. I thnk a simple test will be to hold the UCD vertically and running the engine at different RPM's. There will be varying tank pressures when the airplane is in the air, but I don't think it will be very critical. I built an onboard optically switched glow ignitor for mine. This was supposed to be my winter flyer but did not have the time to complete it then, but should have some fun with it when I don't want to risk my 2 giant scale Edge 540T ies on windy days.
I would have loved to get a Saito 100 fro mine, but already had the 91 Golden Knight. Please let me know how it flew with the tank on the CG.

RE: U Can Do 60
 

coomarlin,

I had a Cline go bad (5 years old). It would not pass fuel through it, hence my inverted Saito 100 in UCD 60 ran very lean and wouldn't start. The tank is pressurized by muffler pressure (on 4 stroke) and the regulator controls fuel flow. I think your Cline is good - bad stopper. Anyhow, I took the Cline off and adjusted needles after several flights 'till it idled/ran good. I put the cowl on and now I'm fiddling with the idle mixture some more (warmer weather). My point is with the Cline, it ran consistently great through 4 seasons. I've never deadsticked with the Cline 'till I took it off.

RE: U Can Do 60
 

It took me just over a month to finely get to the end of this thread.[sm=drowning.gif]
Now I'm going to have to start over, as over time I have forgotten what I started off with. :(

First off I would like to say thanks to Comtempo, I am now a proud owner of one of these contraptions, so add me to the list.

After inspection everything was ok all except the outer former on the left elevator, found it cracked all the way through at the center.

Here is what I'm doing for setup. Staying with the original servo mounting in the tail, placing the tank on the CG as others have in this thread, moving the engine as far back on the mount as possible allowing the cowl to fit in order to help the aft CG.
Tail wheel assembly, I used the tail wheel that was originally on my AW 90 Edge, it bolts to the bottom of the fuse and mounts to the bottom of the rudder by way of rod sticking up through the bottom of rudder. I sliced off 1/6” from the rear of the fuse and epoxy a piece of ply for mounting.

The plane was purchased for the engine and pump I already had in my inventory.

OS 91 FX / Perry Pump
HS-5245MG's on each elevator
Might me light on the rudder but a HS-545BB sets in that spot. Have a HS-645MG standing by just in case I need more tail weight.
HS-425BB's setting on each aileron.
HS-225BB sits on the throttle, located just in front of the tank.
720mh NiMh not yet mounted, waiting for CG placement.
7 channel supreme receiver.
Rudder, 4/40 threaded on one end and solider clevis on the other. Elevator 4/40 all thread on each surface and 4/40 all thread on the ailerons.
Surface horns used were the tri-horns carried by world models.
Main landing gear may change depending on what I have in my inventory.

I have read the post of painting the canopy but I’m not quite sure I am going to go through that trouble aside the fact dark colors drawing in heat.

The factory fuel tank stopper has me a bit worried I may go for an after market stopper as mentioned in this thread.
Now to move away from this topic a bit, I noticed that the Saito 100 seems to be the most popular engine used for this plane. I had both in my inventory the Saito 100 and the OS 91FX but I already had a project in the making that demanded the Saito 100 more and that was the OMP 60 size Yak 54 which is one awesome plane to fly I wonder how these two will compare to each other.

Blackie

RE: U Can Do 60
 

Blackie, Seems as though all your research has paid off. Sounds like a great setup, good luck and enjoy. Joe

RE: U Can Do 60
 

Thanks joe, moving on over to the other thread with quad zillion post in it. :)

RE: U Can Do 60
 

Hi Guys,

I started building my UCD as my Winter plane but now it's Spring and still not done :) I still have a Dave Patrick Edge 540T/DA 50 combo to build for Summer. The pics shows all the mods I made for my UCD so far. With these mods in place, my CG is on the button at 6" I have HiTech digital servos all around using 4-40 push rods, all running off of a Futaba 7 channel RX. I am having some glitching with it and will install a Hitec Supreme 8ch instead. I will be using a Saito 91 Golden Knight and an APC 15X4 prop with a Cline regulator for power. I am using a 6V 1300mA NiMh for my battery pack.

RE: U Can Do 46 and 60 prop/rpm
 

I have a UCD 46 and UCD 60. The 46 has a saito 72 and the 60 has a saito 100. I'm currently running a APC 13x4W on the 72 at 10700 rpm. Is this prop too small for this engine and what is the ideal rpm range. I was planning on putting a 14x4W on the 100. Is this prop also too small?. What prop is recommended for each engine? I'm sorry if this answer is in this forum somewhere, but I did not want to read all 2000 + post. Any information would be greatly appreciated.

RE: U Can Do 46 and 60 prop/rpm
 

the 14 /4w pulls like no other. but spool up gets boreing. if it has to be fast the mas simitar 13/6 works good to .

RE: U Can Do 46 and 60 prop/rpm
 

The 14x4w is way too small for the 100. A lot of people are running that prop on their 72's. Try the APC 15x6 on the 100 or the 16x4w if you want a real stump puller. But like the previous poster said, the wide props take a smidge longer to spool up. I know APC makes a 15x4w, but I've never heard any rpm numbers.

Some people don't mind running their 4 strokes over 10K rpm, but I never do. Ideally I'd shoot for a prop that gives you a max rpm around 10K. Then back the RPM down about 200-300rpms. A running RPM of ~9800 is about right in my book.

RE: U Can Do 46 and 60 prop/rpm
 

The 15X6 seems to the most popular prop for the Saito 100, that is what I run on mine, flying on the OMP Yak 54.

Blackie

RE: U Can Do 46 and 60 prop/rpm
 

Last season on the Saito 100 I ran the 15/6 APC. Right now I have a 16/4 just waiting to spin up. Like Coo said, should be a stump puller. I'm still looking for a 15/5 or even a 15/4 to try. I'll have a report on the 16/4 when the weather co-operates. This weekend looks promising. Joe

RE: U Can Do 60
 

Striker...
......." C of G on the button @ 6".......Is that O.K...[:-]...?...!

Regards, Dave.

RE: U Can Do 46 and 60 prop/rpm
 

I agree I am running a 14''- 8 MK prop with 20% Powermaster cline regulator it seems to be the one it likes the best. I have tried the APC in larger sizes but liked the pick up with the MK. I going to get a larger Graupner prop like a 15''-4 and run some cool power 30% and see how it likes it next. I got a great deal on a case price on the cool power and could not pass it up.

RE: U Can Do 46 and 60 prop/rpm
 

I just picked up a APC 15x4W from my LHS for my saito 100. I'll let everyone know how this prop performes after I break in the engine.