UCanDo 3D
 

I am about to by one of the planes, and have the 2 motors narrowed down, YS 91 or Saito 100. Would like to hear pros and cons, and what fuel/prop everyone is running on the above motors.

Also, what servos is everyone using, and what length servo arms is required to get full lenght for 3D? I am thinking on using hitec mini 5245 digitals (76oz torque each) if they will fit, since they only weigh 1.1oz, and maybe using a lithium pack to save weight, any thoughts on this?

UCanDo 3D
 

thanks everyone

U can do
 

Find out all about the U CAN DO in the threads...there is at least one thread having 200 posts or so, and another was hitting over 100....

If you do a quick look, I'm sure those threads will be found rather easily...

Good luck!

UCanDo 3D
 

there is over 1000 total threads, and was trying to not have to read all of them

UCanDo 3D
 

I have a UCD with a Saito 100 swinging an APC 16x4W prop at 9800rpm. My friend has a YS91 on his and swinging an APC 15x4W prop at 10300rpm. We are both using 20/20 fuel. Pretty much the same power, they both give around 16~17lbs of thrust which is more than 2 to 1 power to weight ratio. The YS maybe a tad heavier? don't know. Mine weights at 7.6lbs....

UCanDo 3D
 

do you keep the fuel tank up front with the saito? if so, how much does it affect it from full to empty?

UCanDo 3D
 

I kept the fuel tank at the stock location. I can't really feel the difference from full to almost empty. I have my CG at 6-1/2" and when I'm about to land, the tail is low and sometimes touches the ground first before the main wheels.

Re: UCanDo 3D
 

I use the large Dubro arms. Large for the rudder, medium for the elevators, and the smaller ones on the ailerons. You can also take the two-sided arms and cut half off each and use those on the ailerons. Those arms will allow control throws that are just a little beyond what is recommended for 3D rates. I bought a Dubro heavy duty control horn for the rudder, and use the second hole out on that.

UCanDo 3D
 

Thanks for the good info, think most definitely going with the saito 100, only changes will be using carbon fiber pushrods on ailerons and rudder since they are long, and I already have extra carbon rod. Does the stock tail gear hold up? Anyone make an aftermarket carbon fiber landing gear? Going to use a lithium pack to save a few ounces as well.

UCanDo 3D
 

Stock tail gear is okay; I noticed it was coming a little loose so I pinned it with a couple toothpicks. Also did the same with the surface hinges; it should be much more robust now.

UCanDo 3D
 

Fly -

Well, in setting mine up I did indeed pour through all those UCD threads :eek: Here's some info I posted in one of the whopper threads. This is what I decided on after averaging all the opinions and tossing in a little personal preference. Oh, and I was also considering the YS .91 and Saito 100. After seeing a few ounces difference in the specs online, I actually had a YS .91 AC and Saito 100 here on my bench and the YS was EIGHT ounces heavier than the Saito. Weighed on our company's postal scale. I was leaning to Saito from previous experience but this confirmed the decision.

Here's my model's info:

Engine: Saito 100 - mounted at 90 degrees to avoid inverted engine issues, remote glow starter, and on-board glow starters.
Prop: APC 15x6
Spinner: factory and still has to be cut for APC (but included in weighing)
Pushrods: upgraded to 4-40. Pull-Pull installed on rudder. Rudder servo installed in bottom of fuse near elevator servos.
Servo Arms: Dubro Supers
Servos: Fut 3003 on throttle, Hitech 425s on ailerons & elevators, Hitech 605 on rudder
Servo horns: Dubro heavy duty - 2 on rudder for pull-pull
Tail wheel: Sullivan with custom linkage
Covering: factory with some added checkerboard and silver
Canopy: painted inside with Pactra Silver and canopy is attached with small silver screws. Small ply blocks installed inside fuse for canopy screws.
Fuel system: 3-line - used fuel dot
Receiver: Hitech 8 with GP charge jack/switch in side of fuse
Battery: whoppin' 1700 Nicad (heavy 6 oz)

And the final weigh-in - including spinner although it's not yet cut and not mounted in the photo - was exactly 7.5 lbs on our company postal scale.

After all the reading, I was certain weight was needed in the tail for the Saito 100, but it balanced on the money at about 5.5 inches. (update)I mounted the battery a little further back and put CG at 6+ inches.

UCanDo 3D
 

My tail wheel - Sullivan with my own linkage

UCanDo 3D
 

anyone have problems getting the saito to run inverted?

UCanDo 3D
 

Mine fired right up. I hit it backward with a Chicken Stick, like a Moki or big Tigre. Runs great.

UCanDo 3D
 

It sounds like everyone is happy with their saito 100s, but still like the idea of a YS up front with pressurized fuel system, even if I dont relocate the tank. I know it weighs a bit more, but may try to offset it a bit with lighter batteries, etc. Any estimated weight it takes to get the plane to balance a 6.5" with a ys up front?

UCanDo 3D
 

Saito with a Cline here, mount the tank where you want. Smartwork has done an excellent job of summarizing all the gotchas, and that checkerboard looks sweet!

Inverted
 

I am installing my saito 100 on my UCD. The carb spray bar is about an inch below the center of the tank when mounting inverted. If I use place my tank in the stock location, what types of problems do I face? I have attempted to sift through the large threads, but haven't found a straight forward answer.

I just wanna fly... :confused:

UCanDo 3D
 

Fly: <<Any estimated weight it takes to get the plane to balance a 6.5" with a ys up front?>>

You could probably cut a hatch, put the battery near the tail and add no weight. On a Dazzler I built, I made the entire bottom of the plane removable so I could juggle components. I put a Saito .72 on it and the battery is almost to the horiz stab - but required no dead weight. I was expecting to add weight on the UCD for the Saito 100 and was going to cut a hatch and juggle back the battery. Whew... no need! :D

Desertrat: Thanks for the comment on the checkerboard. I thought I would add "something" to set it apart.

kirbster: If you go through the mongo threads, you'll probably see references to flooding (during idling), flow while fueling, pumps, and regulators (one reason some favor the YS). Those posts will reference the potential problems you'll possibly see. Others say they have no problems. I didn't want the potential headaches so I mounted 90 degrees. If you plan on keeping the tank where it is, I don't think you'll be able to lower it in the fuse without scooting it back. I think one of the formers keeps it from dropping down in the fuse (in the current position). Even so, you'll have to pull it back enough to get the stopper out of the firewall and then allow enough room for the lines to clear. Stock tank fit is great if you decide to use that. I installed the rear support and siliconed it there and at the firewall to absorb any vibration and it worked great.

-s

UCanDo 3D
 

I'm going to second the cline regulator on the saito 100. I had the tank mounted over the CG and the engine ran great with the cline regulator. I had it mounted inverted and it started and idled great. No problems whatsoever.

UCanDo 3D
 

For the money you spend on the Cline regulator and hassle it would be much easier to buy a YS91 which has equal torque and power of most 120s . just my 2 cents worth Also you dont have to worry where your tank placement is with the Ys motors they run consistent from start to finish from full tank to empty .

UCanDo 3D
 

Thats why I am leaning towards the YS, the only thing I dont like is that you will have to add tail weight, or cut a hatch in the back and mount the battery back there.

UCanDo 3D
 

Fly -

Do you have the model yet?

-s

UCanDo 3D
 

I dont have it yet, but like what I hear about it and think it would be something fun to play with, and a lot less hassle to haul to the field than my big planes. I am just very picky, and want a good setup on the plane. Think I will go with the ys because I have good luck with all of them that I have run, and they are stout. Just trying to think of the best way to get it to balance with the extra weight up front. WIll more than likely go with a lithium pack to help compensate for the extra weight, carbon fiber pushrods on the rudder and ailerons, maybe a carbon fiber landing gear if I can find one, tru-turn light spinner. I wonder if I will have to re -drill the engine mounting holes in the firewall to get the spinner to line up correctly with the 3 degrees of right thrust that is required? I hate having a spinner that doesnt line up with the cowl. Havent decided completely on what servos I want to use.

Cline set-up
 

Anyone have suggetions on mounting the cline reg. to my saito 100? I don't know how I want to physically mount the regulator. To the engine, engine mount, let it hang...? Anybody got pics of their install? Also would like to hear any creative/ clean ways to run the tubing. How are you guys filling/ releasing the pressure, fuel dots...?

Re: Cline set-up
 

I am interested in the same information. I'm under the impression that most people just let their cline hang. I may be wrong, but I thought I heard somewhere that you shouldn't hard-mount it to the engine.

As for filling the tank I believe you should just use the 2 fuel dots that come with the cline and fuel the plane through the T that goes between the fuel filter and the clunk in the tank. The other T line is for overflow during filling. It's located between the check valve and the pressure line in the tank.