toysn909

I have been told you use the mid wing spar and other say top wing spar. what wing is it and how many degree of down nose is correct??????? I do know that correct balance on this plane is major will make either a big kite or total nightmare to fly.

GUY's help me Please.

Oberst

My Discontinued Custom GP Fokker DR1 it was 2 5/8" back on the leading edge of the middle wing, ballancing the aircraft right side up. What Dr1 kit or ARF do you have? That would help us help you if you know what I mean?



Pete

toysn909

I was told buy the seller its a dymond model sport arf but i had to rebuild the top wing and repair the fuse and after peeling the covering off it didn't have the usual globs of glue you see in a arf kit everything was built using epoxy and CA.Plus is was covered in Econokote not the normal plastic film you would get in a arf, the wing is 54in so I'm at a loss to know the exact manufacture.

Oberst

So it's 1/6 scale.

Because my GP Fokker is 60" ( 1/5 almost 1/4 Scale) I don't suggest to do it the same way I did it on mine. (Different Scale, Different Chord, Different Airplane)

I'd go Top Wing about 75 to 85mm back. Me personally, I would go about 75mm slightly nose down. I'd rather be nose heavy on a Dr1 because they can be very tempermental in flight and on the ground.


Pete

Sport_Pilot

Think of all three wings as one wing with a chord from the front of  the top wing to the trailing edge of the bottom wing.  Take 30% of that distance mark a point equivilant to that on the top wing and balance from there.  That should be a good starting point.

toysn909

Thanks I will try that.....

Doug

BMatthews

The DR1 doesn't have a lot of tail area given the amount of wing area. I like the idea of using the top wing's leading edge and the lower wing's trailing edge to find the CG. But instead of starting at 30% it would be safer to start at 25% and work it back in very small increments over a number of flights based on in flight and ground handling until you find the happiest spot for pitch, yaw and ground handling.

toysn909

Well I just got home from the flying field and I balanced the model at about 30 % from the leading edge of the top wing, it took 16 oz of lead to get the model in a about a 6 deg down nose and she flew like a big kite. I had a bit of a problem landing her in the wind very touchy elevator even at 85%dual rate but with a little fine tuning im sure it will be one of my favorites.

Okay now that it flies decent should I add the Flying wires to the upper wing and landing gear there is already wire loops but does it make a difference or just look cool?

BMatthews

OK, balancing at 6 degrees nose down from the top wing of a DR1 means that your true balance point is closer to the 25% mark that I mentioned than it is from the 30% point. Move the support points until the wing chord line is level and see where it balances. THAT is your true balance point.

If you're needing to use dual rates to get the elevator response down to make it controllable then alter the servo output arm or elevator control horn to produce less elevator travel. Obviously you have too much for this model.

The effectiveness of the wires will depend on the structure and where they attach and if the setup you're using for the wires allows them to be tensioned and thus become structural. Otherwise they are just there to look cool.

Anyhow, it's nice to read that the model and your nerves both survived the first day flights....

cfircav8r

My Feedback: (1)

I thought the DR1 didn't have flying wires.

toysn909

There is two wires in the center of the middle wing between the struts and on the Landing gear

cfircav8r

My Feedback: (1)

I know this is going to sound a little pompous, but is just meant to be educational. Flying wires are the wires that are stressed to keep the wings from deflecting upwards when the wings produce lift. Landing wires are stressed to keep the wings from sagging while on the ground. Bracing wires are used to maintain general rigidity of structure such as those between the gear legs or the struts. As far as your aircraft, if the gear and top wing don't move at all (twisting or side to side) without the wires then they are probably just for looks. Just about any sturdy string, wire or line could be used, or just omit them all together.

BMatthews

In the history on the DR1 I read that the plane was built to not require either wires or interplane struts. And in fact the prototype flew without either succesfully. They were added to the production machines at the insistance of the military reviewers that felt the airplane looked weak and that the new cantilever design would not be accepted by the pilots that were used to lots of struts and wires. And in fact the two single wires used were more for show than to make the wing truly stronger.

The landing gear on the prototype however did use a full and functional set of X brace wires.

toysn909

Then I will leave them off, it don't sound like they help more of just a pain to deal with when disassembling the plane at the field

toysn909

To everyone who gave there 10 cents they are a big help Thank you very much!!!