Scratchie

Ok, how's this one.

No Vanessa rig, pencils supporting the plane at the CG as marked on plans, inverted. No leveling devices used, 35g lead on tail (based on the Vanessa rig trial). I thought maybe for the maiden I'd take off 7g to ensure that the plane is nose heavy, how does it look?

DavidAgar

My Feedback: (108)

It looks as if it is balanced and ready to fly. You might want to make it a shade more nose heavy and test fly it. You can always remove the nose weight if you need to. Good Luck, Dave

Scratchie

I think it looks good, but it's my first kit and would rather wait a day or two and get it right. When balacing inverted, how much "down angle" should there be on the nose? 10-15 degrees?

Lnewqban

Scratchie,

This is indeed the best balanced plane that has ever been maiden!!!![sm=wink_smile.gif]

So,......did the Vanessa and the pencils agree about locating the actual CG, as they should?

Level as it is is just fine; however, I would reduce that throw in the elevator that the picture shows, it seems too much for maiden.

Also, check that the clevises at the elevator's servos don't get overstressed at full deflection, because they could brake due to fatigue.

gsoav8r

My Feedback: (6)

Scratchie, I can appreciate your apprehension but if its balanced per plans and toward the front of the CG range you shouldnt need any "slightly nose down".
Besides, putting 10 ounces of fuel in the tank will give you all the nose down youll need. And as long as you dont fly her dry youll still have a couple extra ounces of nose weight in the tank.

The nice thing is that you now know that you can trust Vanessa.

Cheers.

Scratchie

what do you mean by checking the clevises at the elevator's servos - the placement of the control horns (for both the elevator and rudder) relative to how the push rods came out of the fuselage was not one of the highlights of my model building. Also, I forgot to put that little piece of tubing around the clevis on the elevator and throttle - how improtant is that?

gsoav8r

My Feedback: (6)

Not to put words on anyones screen but I think Lnewqban was mostly saying to just check that nothing is binding and everything functions smoothly.

As for the tubing around the clevis, its a handy little security device. Knowing how much you love your new baby Id take the time to install the one on the elevator at least. The elevator linkage endures a lot of stress.
I dont normally bother with them on the throttle linkage because it endures little stress as long as it isnt binding or sticking.

Cheers.

Scratchie

Thanks eveyone - I think it's time to get it in the air

Charlie P.

Did you balance her laterally? Side-to-side, that is? It will make your loops and other maneuvers hold their axis better.

I hang mine from the prop-shaft and tail wheel bracket (or other suitable central point) and add cents to the high wing at an aileron servo location. When it balances I pull the servo use black electrical tape to attach the cents to its base. Occasionally I have one that needs more weight and so I use sheet lead or trimmed wheel-weights.

mikegordon10

Well the question about how the Vanessa's CG point and the pencils CG point was never answered. Were they different or not?

Scratchie

Vanessa and pencils were exactly the same, each indicating 35 grams of weight in the tail. Vanessa used a level to ensure the plane was perpendicular to the plumb line. No leveling (except for eyeball) with the pencils. I meant to laterally balance it and completely forgot - thanks. I'll be charging the batteries tonight and flying tomorrow morning unless work/weather gets in the way. I'll post before and after pics - my goal will be the same as with my trainer, get it up and down in flying condtition.

Charlie P.

Glad to help. No where near as critical but it can make in-flight trimming and performance better.

I may just have to put together one of those Vanessa contraptions and play around.

By the way: God and nature do not determine where the center-of-gravity should be. The "suggested" spot is where the designer/builder decided his model flew as he thought it should. Most designs have a relatively wide parameter and some a narrow one. It is usually better to be conservative and start out nose heavy. Because, as the old saying goes, "A nose heavy plane flies poorly. A tail heavy plane flies once."

I happen to like doing inverted flat spins and that works best with a "neutral" C.O.G.; usually near the rearward recommended range.

Here's a simple test for C.O.G. trim. Set the throttle so the model is flying level. Now bank to 45ΒΊ and center the controls. If the model quickly noses down you are nose heavy. If it noses up you are tail heavy. If it stays in level flight for a three count and then noses down you are about optimally trimmed.

And, as someone mentioned earlier, the fuel in your tank is always additional nose weight. The above trim will change as the tank empties, so try it several times during a flight before making weight corrections.

And, always, do what you can to adjust the balance without adding weight. Move the battery, shift servos if possible, play with the gear. Remember lighter flies better.

Lnewqban

This is what I tried to tell you in my previous post.
Please, check the schematic.
Nothing to worry about now, those clevises will no fail for some time, especially if they are well aligned.
It is just something that has happened to me before.

Best luck with that beauty, Scratchie!!

eagledancer

when your planes start getting to this size pencils and the 2 finger method no longer works. 1/3 sopwith camel. have not weighed it yet but near 40 lbs

Scratchie

Finally had the maiden flight - all went well. The plane rolls, loops and fly's inverted easily. The new OS .46 AX was very quiet, must be an improved muffler. The plane wasn't as fast as I thougth it would be, all in all I'm pleased with the BUSA kit ($80). I have pics of the entire build if anyone's interested.


Now I need a kit for the winter, any thoughts on the discontinued Top Flight AT-6?