I am balancing my UCD today.....sorta.

It looks like I need 4-5 oz of lead, but I am having a bit of trouble. The GC must be somewhere inside the wing core, (vertically), because whether I place it upright or upside-down, the plane will tip in either direction once it is more than an inch over the top. How do I tell if it is balanced? I am using a GP CG machine. (I really hope there is a better way).

I'm off to Wal-Mart to buy lead. I ain't paying $12 for 6 oz of lead. (not bitter, just cheap).

Thanks,

Mark

Hi!
Balancing machine ..???
Just trust you index fingers...!!!

Regards!
Jan K

Need some more info Mark. Which UCD? Is it nose heavy or tail heavy? My 60 size UCD w/100 Saito balanced dead on. I have the battery located at the trailing edge of the wing and the fuel tank on the cg.

It's a UCD .46

It's severely, (4-5 oz) tail-heavy. I installed a Saito .82a. The battery is as far forward as possible, unless I cut a hole in the front former and slip it under the tank, which is an option. I am stiill having a problem determining how far off it is with my CG machine.

Should I try it RSU with my fingers? or do as the directions say and balance with the plane upside-down?

My beginner-ness is showing through here, I know.

Just looking for a shortcut.

Thanks,

Mark

Balance the plane with the majority of the weight below the balance pivot point. Use your index fingers on each wing panel.

Dr.1

SON OF A............!!!!!


I balanced it, it took like 5 oz of lead screwed and epoxied to the firewall. I spent most of the day farting around with that plane. In the instructions, BALANCING comes BEFORE applying DECALS. Well, in with the DECALS was a small, 3x3" piece of paper that said 'product improvement' this model may be flown with a CG ANYWHERE between 4" and 6" behind the LE of the wing!!!!

Send Prozac!!!

I'm not suprised by the addendum. Considering they market the ucd series as a 3d trainer, I'm sure they initially set the balance point well up towards the nose to make it more docile. Then they probably got a lot of a responces from ppl that the cg needed to be further back to fly 3d well, so they put the addendum in. That would be my guess anyways. Think of it this way. Now u can slowly shave off weight till u find where u like the balance point, starting from a safely nose biased starting point.
-John

See? Reading instruction just gets you aggravated!

Mark, is there room inside the cowl for the battery? If so, just attach it there and drill a hole in the firewall for the wires to run through.

LMFAO Minn!!

I could remove all the weight and leave my battery where it is and still be well within the 4-6" range. For now I will leave the weight on and fly it until I am used to the new plane and then begin removing weight. Final dry weight is just shy of 6 lbs. When I remove the weight I added it will be near 5.5 lbs.

I built this plane as a 'practice build' for my Mayhem, a very similar plane, just bigger and made by SIG. (I like SIG). The Mayhem will be running a Saito 125a, so I bought a Saito .82 for the UCD. Once I bought the engine, it was no longer a 'practice build'. I got the ARF at a discount on one of Cheif's monthly unpublished price lists. Now I have nearly as much money sunk into the UCD-shaped hole as I will in the Mayhem-shaped hole.

I did leave the wheel pants off, however. I have seen them go right through the wings when the gear fails.

Prozac alert canceled. The sound of that little Saito .82 idling at 2k is better than pharmaceuticals can deliver.

Thanks,

Mark