Bruiser-RCU

My Feedback: (1)

I bolted the engine (Quadra 35) to the firewall tonight and the plane (fuselage only) did a nose drive to the carpet. It takes a lot of pushing to get the tail back down.

The airplane is not covered yet and the only equipment installed in the fuselage is the engine and gear legs. The tail surfaces are not glued on yet either, but I did set them in place which helped a little but it stayed on it's nose. I even put the servos on top of the compartment and it did not settle in. Then I put a 1200mahSC battery on top of compartment area. It did not drop the tail but when I pushed it down, it stayed down.

So to all you folks out there with planes powered by Zenoah, U.S. or Quadra engines, does this sound right? I know putting on the covering and tailwheel will help, but there's still no cowl, windshield, tires or wheel pants either. I am wondering if I should move the elevator servos under the stab.

Please advise,
-Bob George

beepee

Bob,

I am at a similar stage as yourself. I will be powering mine with a US 41 on CH ignition. I am not surprised by the results of your tests. My fully assembled and balanced birds will not come off their nose when tilted up. If it were me in your situation I would complete it per the design. In the end, a little bit of balance weight added to the tail will have a large effect on the CG position.

Good luck!

Bedford

Bruiser-RCU

My Feedback: (1)

Bedford,

I guess it's just you and me with a simular combo...

Your engine should be a little lighter without the magneto and flywheel on the engine.

I am pressing forward because there's just too much stuff that still needs to be installed. I plan to mount everything I possibly can and check the balance one more time before I start covering it.

So let me ask you a couple of questions. Where are planing to install your radio on/off switch? How about your engine kill switch? Last question--where are you putting your receiver?

This is my first large aircraft so I don't know what is considered "normal" for this size. It definately is different than .46 size airplanes...

Thanks for replying,
-Bob George

beepee

Bob,

Great looking shot. It looks like you did what I have been kicking myself for not doing: opening the fuselage above the wing for a scale sky light. Did you stab the wing halfs into the fuselage or themselves per design?

Have you checked prop hub position relative to the plans? I see you have built the kit engine mount. Is it giving you clearance for your muffler? I dispensed with the kit's mount and am bolting the engine right to the firewall using the stock US Engine spacer. I am guessing that your Quadra has no spacer (my Q42 doesn't). Anyway, engine position will be critical to balance. The farther back you get it, the less tail weight you will have to add.

I have mounted, or planned the mounting position of all my radio gear. The fuselage servos are mounted per plans. The two battery packs (main + back up) and receiver are mounted in the same area as shown on the plans. Radio switches are on the fuselage side by the radio compartment (direct control). The ignition switch is on the side as well, up by the cowl. I also have (for the first time with my gassers) a separate servo controlled ignition kill switch. The servo is separated from the ignition system (to avoid radio interference) by a ny-rod acting against a limit switch.

At the rate I am going, you will be in the air before me.

Good luck!

Bedford

Bruiser-RCU

My Feedback: (1)

beepee,

Don't count on me being first in the air. I tend to get hung up on the small stuff and I am feeling I'm about there.

I had to have the center window so I made my wing three pieces. The outer panels are slid over the tube and held in place by a nylon wingbolt thru the ribs. Then the wing bolts on just like the original design with the two dowels in the front and two wingbolts in the rear.

I have not looked at the plans for so long I did not remember they showed locations for the battery and other stuff. I will have to look again.

I did use the firewall that came with the kit, but I modified it. I had a Great Planes isolation mount kit and I used the rubber grommets that came with it. I had to open up the outer bolt holes for the grommets but that was easy with a Dremel. The cup mount just fits between the grommets. If you try this, be careful here because there are at least two different style cup mounts on US Engines. One is 5/16ths wider then the other style, which I think is newer. The wider one won't fit.

I don't have a stock muffler for this engine. I have a Bennett muffler that came with the engine when I bought it.

What are you doing for tail bracing? I had some 1/4" wide, .100 thick aluminum strips cut but whe I tried to bend them, the strips broke. I'm back tot he drawing board on that now.

-Bob George

beepee

Bob,

Sounds like a challenge of who can be the slowest. Your on!

I have a Nosen Cub with the wings stabbing into the fuselage and I thought about dublicating that design on the Decathlon. It does require functional struts, but I have done that anyway.

Make sure your muffler bolts are good and firm. I have my engine (now on another aircraft) in a semi-soft mount and those muffler bolts just loved to back out until I finally locked them with safety wire.

I can't tell you yet that my tail braces are going to work. I have used 1/16th music wire with soldered electric terminals for the end fittings. These will have more than enough strength so long as they do not develop harmonic vibrations through the normal engine operating range. I won't know about that until I crank it up. If I run into harmonics, they won't last one flight, in which case I will go up a size. Not for the strength (wouldn't do any good), but to change the harmonics.

Good luck.

Bedford