HELP WITH BALANCING BF - 109 SERIES 500

[PD/TEE DEE]

I've overcome my tissue covering issue thanks to some help from forum members but this one is a little more difficult so any help appreciated.

Took my plane to a vacant allotment next door with long grass and tried a few glides - absolutely hopeless! Nose dives some of the time - other times if aimed in the air a bit more - more of a quick flip backwards - tried the stabilizer bending as suggested in the little Guillows handbook but not much difference.

However I then realised I'd been a little hasty because the plane hadn't been balanced between two books but now even more confused - the plane weighs 1.2 ounces(not sure if that is good or bad?) - it requires lots more weight in the nose to balance - in fact another ounce or so - surely this is way too much and will only contribute further to the nose dives into the ground? Only good news is I think a .01 motor weighs a little over an ounce so it would be balanced with one fitted which was my ultimate aim.

I am assuming however that if it won't glide I shouldn't attempt to fly with a motor?

[Xanadu]

Check out this fellows site in the UK for help sections on getting stick and tissue plane set up properly for flight.
Lots of useful info for what you need.

http://www.ffscale.co.uk/index.htm

[PD/TEE DEE]

Xanadu - thanks for your reply - yes I have been reading some of the articles at the site you mention - some very useful information there by the look of it. However I'm still at a bit of a loss as to why my plane would need several Australian 10 cent pieces in the nose to enable it to balance between 2 books - seems an awful lot of weight. The point of balance on my plane at the moment(without extra weight being placed in the nose) is way behind where it should be - somewhere between fuselage formers B3 and B4. I'm thinking of perhaps pulling the rudder and stabilizer out and putting some larger in just to see if that counteracts the nose diving but again at a bit of a loss as to whether I should have to go to that extreme.

[lennyz]

If you are going to power the model with a glow engine-weight shouldn't be that much of a problem.You shouldn't have to rebuild the rudder and stabilizer. Try your glide test with the engine installed. You may not get as much glide as with a lighter weight but the flight characteristics can be asdjusted to give you a nice glide. Also your kit should have come with a lump of modeling clay for balancing. there is quite a large amount needed in the engine cowl to balance the model. This should have been covered in your models directions for flight trimming.

[supercruiser]

1.2 ounces comes out to be about 34 grams, a little heavy but still within the flyable range. Mind you a .010 engine will have excess power for that size model.
Enlarging the stablilizers will tend to make the balance problem worse.
Like suggested earlier, go ahead and put the gas engine on the plane and get it to glide in that configuration. It must balance where the plans indicate or close to it. Don't know where formers B3 and B4 are in relation to the wing on that model, if that's more than half way back from the leading edge of the wing (50% percent chord) it will likely have unpredictable flight characteristics or not fly at all.
Once it is balanced, My guess is you will need to deflect the elevator UP quite a bit to get a decent glide.

[PD/TEE DEE]

Supercruiser and others who have offered assistance - I have made some progress - 4 x 10 cent pieces stapped to the nose is required to balance the plane - this also now gives better flight results as I have also removed the rudder and stabilizer and inserted a triangular piece of balsa to lift the entire stabilizer up and reglued everything - plane pulls to the left but this is the side I wish to attach tether line later on so thinking about leaving as is. Good idea or not??

All that extra weight in the nose feels ridiculous but seems to work.

I don't have my TEE DEE yet so can't try it - but it would be a similar weight to the coins.

You blokes have me a little confused on deflecting the elevator UP - should I have made this adjustable - I thought with a Guillows everything was fixed _ I would be interested in any internet material on building adjustable stabilizers and rudders for future models?

[supercruiser]

for making adjustable control surfaces go to smallflyingarts.com and look in the feature articles section, there is a tutorial on hinged control surfaces.

Adjustable surfaces are more practical for flight trimming. some people glue a stiff paper trim tab to the trailing edge of the rudder and elevator. Then it's just a simple matter of bending the paper tabs. The Guillow instructions usually say to breather on the fixed tail surface and bend it. I have found this works only on very lightweight models.

[Daniel, a scratchbuilder]

Supercruiser and others who have offered assistance - I have made some progress - 4 x 10 cent pieces stapped to the nose is required to balance the plane - this also now gives better flight results as I have also removed the rudder and stabilizer and inserted a triangular piece of balsa to lift the entire stabilizer up and reglued everything - plane pulls to the left but this is the side I wish to attach tether line later on so thinking about leaving as is. Good idea or not??

All that extra weight in the nose feels ridiculous but seems to work.

I don't have my TEE DEE yet so can't try it - but it would be a similar weight to the coins.

You blokes have me a little confused on deflecting the elevator UP - should I have made this adjustable - I thought with a Guillows everything was fixed _ I would be interested in any internet material on building adjustable stabilizers and rudders for future models?

Hey. So you know how to adjust the CG. When you deflect the elevator up, the plane goes up because the tail goes down (elevator pretty much works like spoilers/ailerons-the aileron goes up, the wing goes down and the oppsite). Opposite for when it goes down. I would suggest using an electric motor, since I see the plane you built is a small one. So make it an electric motor. Or even a rubber powered one (I hate rubber-powered planes, though). You'll need a little battery too. I would suggest you download a demo version of this program- at website www.motocalc.com in the download section of the web-site. Download it. And then punch in the characteristics of your plane, and what you want it to be in the 'motor wizard' in the 'File' drop-down menu. It'll give you the propeller you need, the engine name, and the battery name. So try that and see what you can find out.

P.S. I would suggest getting planes with a wingspan of at least 68 cm (centimeters). At least I design my own planes with the wingspan around that and they are very moveable, comfortable, apparantely small, and fly well. I am even making a plan of a ducted fan model with a 68 cm wingspan.

[skywarp]

I have a quick balancing question with respect to these models. Do you folks balance these planes as instructed by Guillows with pins in the wing tips and the plane right-side up, or do you balance them upside down with the balance point at marked at the wing root? I know in RC aircraft they are balanced upside down at the wing root and this seems correct to me. Thanks.

[supercruiser]

I guess either method will work. I put pins in the wingtips.
Some models have a flat bottomed fuselage. I have tried placing them
on a dowel or pencil and rolling the model back and forth while on a flat, level table to find the balance point.