U Can Do 3D/ engines
 

Bla Bla Bla

U Can Do 3D/ engines
 

Yeah yeah yeah :D

U Can Do 3D/ engines
 

was trying to decide between a .61 ST 2 stroke or a 1.20 YS 4 stroke which I have lying around...thinking more towards the former because it clearly says the 1.20 is too much for it....but at the same time it won't hover too well with a .61....darn....I wasn't planning on buying another engine...

U Can Do 3D/ engines
 

R/C,

I hate to say it, but you will not be satisfied with the performance of the .61 on a UCD......I'm on engine #3 on mine, started with a lightweight .80 four stroke, would hover, but close to full throttle and slow pullout. Then went with an OS91 FX, pullout was great, power was great, but you got an additional 4 oz of goop on the wing from the 91 exhaust. I was also able to go from a 14/4 APC to a 15/4 or 16/4 APC. Engine #3, which hopefully will be test flown tomorrow (weather permitting) is a saito 150 (I know, overkill :D :D :D, but I think this will be the closest TOC type package in a small frame. Power to weight ratio should be between 2-1 or 2.25-1. Fuel consumption should be less than the 91fx, giving me about 10-12 minutes of 1/4-1/2 throttle for just about anything.


You can use anything on this airframe, as long as you do some reinforcement (where GP should have put it in the first place), and remember that the throttle stick is the one on the left. The ONLY time you should be close to full throttle with this plane is while panicing out of a hover. Go with the YS, you will not be sorry...>:D

Steve

U Can Do 3D/ engines
 

ehm....I fly mode 1...but thanks for the pointers...I HATE having to change engines.....

U Can Do 3D/ engines
 

stevezero..anyupdates on you new engine setup?....what mods were you reffering to?...wing and gear area reinforcements?

U Can Do 3D/ engines
 

R/C,

I havent been able to fly it yet with the 150. I havent put the bearings in yet, due to being under the weather, and getting the popup camper ready for the trip to the Joe Nall on Thursday. 25mph winds havent added to the desire to fly either. I have beefed up the landing gear area with some epoxy, and a little bit of stock, but didnt want to go too beefy and risk doing severe damage on a hard landing. I tore the entire block out on a botched harrier landing when I had the 91 on it, and it came out very cleanly, so the repair was easy. The firewall is pinned, with a little bit of tri-stock added. I've also threadlocked all machine screws so they dont vibrate out. I'm stuck going out of town mon-wed, but might take the fuse with me to work on while I'm stuck in the hotel.

I've also monokoted the hingelines on all surfaces on both sides, so flutter, even at high speeds will not be a problem. I put tail wires on it right from the get go, and have no flex in the tail at all.

I've put my battery all the way in the rear of the fuse, right in front of the servos. It's a small nimh 1600 pack, so if i need a little more weight, I'll put the 5 cell 2500 nimh pack in there.


The neat thing about the saitos is that there is only 1mm difference in the 120 and 150, so the cowl fits cleanly and lines up on the stripes very nicely. My saito isnt brand new, so it doesnt have all the oomph of a new one. If I were going with a new engine, I'd put either a saito 100 or a saito 120 on it. I've seen one fly with a saito 120, and one with an os 120 four stroke, and both were very impressive. The power was where you needed it, at the low end of the throttle, unlike the 91fx. It was just a pain trying to prop it.

I'll try to post a couple of pics of the engine install when I get back into town.

Steve

Steve

Saito 150 install
 

Here are a couple of shots of the saito 150 on the nose of the UCD. The cowl wraps totally around it, very clean installation. I'll try to button the cowl up and take a pic of it this afternoon. That is an APC 17/6 prop on it, and I have yet to take it over half throttle out of shear fear on the ground. LOLOL. I still have some tank issues I need to address. I am going to do the floor mod and drop the tank that people are doing in the UCD thread. Still havent flown it with this engine yet, been down at the Joe Nall (what a hoot that was)

Steve

U Can Do 3D/ engines
 

Prop clearance is still well over 2 inches. If it sags on hard landings, then it will get a spreader bar, or carbon gear. I will weigh everything and compare it to the weight of the 91 fx. It balances laterally much better (had to put a bunch of lead on the right wingtip to balance it due to the os muffler). A 5 cell 1000 mah nimh battery pack is resting just forward of the rear servos. Might not have to add any lead at all to the fuse (maybe 1/2 - 1 oz) I wish I would have gone with standard size servos instead of the minis on the elevators, would have given me the extra weight without all the cutting and gluing to hold the 225's.

Steve

U Can Do 3D/ engines
 

Make sure you have enough openings in the cowl to let the air out. With the muffler blocking the main outlet like that you might not have enough cooling air flow.

U Can Do 3D/ engines
 

YS 110. Spins a 16x8 atover 9500 I think. Same weight as the YS 91.

U Can Do 3D/ engines
 

I've got plenty of openings in the cowl. Both cheeks are open to cool the case, and I have a large opening at the bottom of the cowl, and at the bottom front of the cowl to cool the head. There is still alot of room for air to pass over and exit down the bottom.

U Can Do 3D/ engines
 

What about a GMS 120??? would this be too much for the UCD??