Replace the stock stopper with the Ernst super stopper. They come with warp-resistant nylon plates. Quantum carries that too. FWIW

rajul I can't tell you how many times I have read about stock tanks/stoppers failing. I never use stock tanks. I used a Sullivan 13 oz standard on my UCD after having been burned twice by stock stoppers when I first stated flying. Never had a problem since. I should have listened to good advise the first time I had one fail, but after two failures there is no excuse.

Joe, I can't imagine why the delay on your parts. I have ordered from Quantum before and they responded promptly. I needed a Sullivan Megatron starter for my first Pitts project. No one else had one and they were on back order four weeks. Quantum sent one to me and I had it in just a few days. Maybe the parts were on back order. I waited two weeks to get a new set of wheel pants for the WM Extra.

I agree with you Roger. I also reinforce my tank with filament tape

I had nothing but excellent service from Carla (Quantum) so far. She went out of her way to get non-stock items for me, more than once.

Mike ,
First off, appologies for casting a shadow of doubt over the C of G figures you suggested for the UCD centre mounted tank set up... i've still not put this entirely to bed yet...anyway if and when i put this YS in the UCD, how much extra weight do you think i'm adding on here to support the YS's fuel system needs...pipework, filters, NRV's and tape round the tank,which in all fairness, i find a realy bizzar concept..stoppers poppig out,split tanks..fuel filled fuze's...im not sure i want the remotest chance of these problems.... regards Dave.

LL it will be okay just change the stopper or put a seamless tank in place of the stock one....The added weight is not enough to worry about.... JW

LL, calm down, I said it before, whenever you have a bout with drapes something snaps. The YS110 will overcome any weight penalties with flying colors. You just have to be creative when placeing the components to achieve your preferred CG. BTW, who is Mike?

Raj, its probably just a snag with my order, I'll probably see it Monday. Got my regulator from Cline in two days. Thanks for the tip. Joe

Give Carla an email or a call. I'm sure she'll sort it out for you real quick. I like her honesty. I always get charged actual shipping, not a cent more

Has any one ever put a OS 108 2 stroke on a ucd. I am getting ready to fly mine and I went out and started it today. It has so much thrust it is scary. It is hard to hold on too. Just hope I am not going to tear the wings off. Also what is this about right thrust. Is there any built into the kit or do you have to add it with washers behind the mount.

Thanks
Bill

Bill, as far as the 108 goes, give it a whirl, keeping in mind that this model is not designed for speed. With 3D applications, all these manuvers are performed right around stall speed. As far as right thrust goes, it is not built in. There was a poor attempt by the GP engineers to provide a small offset in the vertical stab but so far with the powerfull engines everyone is running its not enough. You will have to add right thrust. I'm waiting for thrust plates for this application. washers work, but will compress into the wood. The plates come in 1,2 and 3 degrees eliminating the guesswork. I will go one step further and see if it requires any up/down thrust angle as well.

Raj, since you have been following our little forum then you have reviewed our discussion of the tank on the CG. Being an old UCD hand is there anything you would like to add about how the plane responds to the tank on the CG and perhaps methods of balance. Thanks, Joe

Joe ...
Yeah....chill .. your right...There's just a couple of tiny, tiny, things i'm not 101% sure about with this YS thing ... you see 30 years ago i remember standing with my nose pressed to the shop window just gazing at the O.S . stuff i couldnt afford....These days thats all i've ever bought ...performed effortlesly ..never, ever, missed a beat...no problems whatsoever in any shape ,size or form...so what am i doing jumping ship..?
O.K. i was looking at the right thrust thing today on the UCD...no form of compensation for the torque any where at all ...so it looks like some form of thrust washer/plate....tell me ,what sort of figure would we be talking about under the edge of one side of the eng mount where it meets the firewall for 1,2, & 3 degrees of r/thrust..? ( 0.5mm, 1.0mm ,2.0mm or what..)

Mike is " Rajul "...yes..? .Dave

Dave, 3 to 4 degrees is about right. With Ernst plates, I don't have to worry about the washer thickness or sinking into the wood, as the plates come in exact angles (you could also stack the plates to get up/down thrust and left/right thrust) and spreads the stress on the firewall over a large area.

Mike convinced me a while back that the thrust plates are the way to go, therefore my pending order. No guess work. On my last one I had two 1/16" washers stacked on top and bottom to angle it. As far as what angle that attained...... I don't know. What I do know is that it needed more, but the plane didn't want to hang around that long so I never got around to it. The plates are like $2.50 for three. As far as the OS engine, I feel the same about my trusty Saito, after much pondering and lamenting over the big ol' YS I decided that with that money I would be better off with the Saito and saving for a gas engine for my next act............28 percent WILD HARE EXTRA LS oohhhh yeaaahhhhhh I think I'm getting wet !!!! Joe

Speaking of CG, along time ago someone showed me a trick for setting CG in both directions at one time, To this day Ive used it and never had to add more than a click or two of trim.
You have to find the Center of the fuse/wing and glue in a doubler, then drill a small pilot hole to thread in a hook, set the CG by setting weights around on the plane and wing tip to get a perfectly level plane.
Pull out the hook and put a trim dot over the hole.
PS love this Forum and all the great advise!!!!
Danny

BTW, I forgot to ask, My plane with a OS91 4 is about 8lbs?? way over what the box says! Is this gonna cause a problem with this motor swinging a 15X6?
Thanks,
Danny

Joe, my GP cg machine works well. I tape two 3/32" thick balsa sheets ( approx 3"x6"), one on each side of the wing root. This is to prevent depression on the covering over the open bay caused by the pedestal of the cg machine.

Pook Mike, Bill and anyone else that wants to chime into this long lasting thread, welcome.


Pook, I really like your balancing machine. Now thats what I call perfect CG balance. Very nice work. As for the weight, I thought mine was heavy @ 7 lbs. 14 oz., which is pretty close to 8 lbs. Joe would be the better one to respond to this. he hates weight... I am using a 14/6 APC prop on mine and I have no problems. I can take off in about 15 to 20 feet and go vertical and just keep on going unlimited.

I learned today that four others in the club have ordered UCD's. We will soon have a squadron in the air. A few others are interested as well. Hard to hold a good product down. Like I have said, I enjoy flying this airplane more than any other that I have in the hanger. Just a fun plane to fly when you just want to fly and not think about anything else.

Thanks JW, I did the same but I can't make my elevator halves stay together, the short pushrod side always gets more deflection than the other side, up or down. I'm using Hitec 605's with Dubro long servo arms, both servos equally centered. How did you manage to make yours travel equally?

J.E.

Your geometry has to be correct first. When your elevators are at neutral, are the servo arms perfectly perpendicular to the pushrods ?

I think that the stated weight is with the smallest recomended engine, use of the cheezy plastic hardware, supplied spinner, wood prop, 2/56 control rods, foam wheels, standard servos, 4 cell battery, etc. With the larger engines and upgrades of hwde. the oz.s add up. Joe

I didn't have much trouble getting the half's to line up ,you my want to try HD control horn's ...I found that all the spine's on the control horn's to be centered a little different...Also I made very small addjustment's to the length of the push rod...the rest was easy, just a 1/2 turn at a time on the clevis , and the elevator half's came out with the same amount of travel.....JW

Hey there,
I don't remember who asked about the 108. I have it in mine .the only problem is i think the tank is to high. The fuel just pours right out into the carb. It's a real PIA to get it started. Maybe a fuel regulator will work. Im going to try to mount the tank a little lower and see what happens..
When I'm trying to hover I loose power and it does a nice tailslide. I have no power from 1/2 to full power.. It just craps out,and I got to bailout of the hover....
Good Luck,
Frank

Try a cline or Iron Bay regulator

I have a UCD 46 and I have a few question I was wondering if anyone could help me with. I was wondering whats the advantage of having a push-pull system on the rudder and do I need one on the .46 UCD. Will this be a problem moving some of the weight from the servo forward a little. What is the best way of strengthening the landing gear before it breaks away. Any comments will be very appreciated.

Gone a bit quiet has'nt it...?

got my ernst thrust plates...

got the O.S tuned pipe....

oh, Joe who DID kill Laura Palmer...?

LL, just finished drilling and mounting my thrust plates. I like the way they cover up the hole that the fuel cap stuck through. Pretty slick.
Yes it has been quiet. Inexplicably quiet, you could hear a plane drop. I hope the silence is not indicative of failure this past weekend. I know that there were going to be some maidens..........Matt? Its late Monday evening and I've heard no trumpets or exaltations from the tribunal.
As far as poor Laura goes, we may never know. Personally I think it was the little lame man in the "Black Lodge". He wanted her. Was murder worth not being able to have her? And what was Pete "the keen fishermans" aliby. In finding the body, did he not know where to look? After lamenting greatly over the years, I've come to realize that some things Mr. Lynch will take to his grave. Joe