Photos of Tail heavy Pathfinder Previous post

Following is some photos you requested showing weights size and position. CG picture and others.

Thanks for the help.
Inverted

I could not get a weight photo alone or do I have a scale to weight the plane I think it is about 45 to 50 oz.

Paul...I would put a tank and the stock muffler on the critter, and add a tail skid and fly it.

See Ya

From your picture, it look like you are balancing it about 1" behind the LE. If true, it look more nose heavy that tail heavy.

Are you saying you have 12oz of weight in the tail? I find that very hard to believe. I don't see any weight back there in your picture.

The first photot shows cg 3/8 inch or 2.5 inches behind leading edge.
The fourth photo shows three 4 oz. weights in the nose to correct the heavy tail.
Thanks for everyone who replied.

Wait a minute....... Inverted 2 ?? Sure don't know Paul S........
Anyway..... did you try to balance it with a tank and muffler in place??? A metal tank, heavier nose wheel, stock muffler, etc., and you can lose some of the lead weights.
Bill <><

I'm totally lost Bill. That does not look like Rake's car in the background of the picture, either. Could there be TWO identical; cases?

This reminds me of the old Sci-Fi movie Doppelganger, where there were two identical earths, with teeny but bizarre differences, like electrical polarity....

We'll have to give John a call from Marietta and stir him up.

LAST EDITED ON May-13-04 AT 11:17 PM (CDT)
 
I still don't know what you are talking about? What is 3/8" or 2.5" behind the leading edge. If you are balancing 2.5" behind the L.E. at the fusage, I don't think that you are too tail heavy. The center chord on the Pathfinder is about 12", so 2.5" behind the LE would put it about 21 percent of chord. That is not an un-reasonable number.

From your photo, it look like you only have 1 oz of weight in the nose. Why don't you put back the stock muffler, and add the tank before you measure the C.G. It sure doesn't look like 12 oz of lead in the nose. How are you measure your C.G. Where are measure the C.G. ? Are you taking is from the midpoint between each wing panal to get the MGC (Mean Geometric Chord). Please read Brett Article on my web site on "Bench Trimming"

My plans show the CG at ~2 3/4 " back from the Leading edge, almost directly over the where the main gear mounts to the wing (aft of the spar).

Also as I understand, the plane was designed to use a stock FP40 muffler (I am not sure if this was the RC or the CL muffler (the current RC muffler is heavier). I note that your icture shows a tongue muffler (I think). I think a stock muffler is in the 2 oz (or more) range.

Inverted,
If I understand you right,the c/g is 2 1/2 inches behind the leading edge.If this is correct then take the weights off and put you tank on and go fly it.My Pathfinder has an os 40fp with a tube muffler. The muffler weighs 1 1/2oz.The c/g is 2 5/8 back from the leading egde.I hope this helps.

Gordy

That is Johns plane I was just helping him get some photos out there for a better idea of what was going on.

Paul

There has to be an explanation here, that hasn't been discovered.

Is there some confusion going on between metric and English units, perhaps? 1" = 2.54 cm. The balance photo does not look like 2.5" to
me. Perhaps it is 2.5 cm?

That doesn't look like 4 ounces of lead to me either..

Something is not adding up, still. Too many Pathfinders get built, flown, perform well, without even looking at the CG!

[photo not recovered: 3e69bb3870f12ad5.jpg]

"There was never a genius without a tincture of madness." -Aristotle

Does anyone else think the main gear looks too far forward, for a trike gear?

>Does anyone else think the main gear looks too far forward,
>for a trike gear?

Ron B.
F4Fguy

As I remember the design,the gear are in specified position,and yet it sets in the normal trike position,nose wheel down.This reinforces the notion that it's not tail heavy.

Pull all the weights,install the tank and stock muffler,and FLY IT.THEN trim to your flying style.If it's too sensitive,as it will be if it really is tail heavy,fly the tank out straight and level.Then,and ONLY then,add weight(front or rear)as needed until it flies the way you like it.

LAST EDITED ON May-16-04 AT 08:45 PM (CDT)
 
My plans show the gear blocks to be 2 5/8 from the leading edge to the center of the blocks or the center of the wire in the wing. But that does not look like what we're seeing here!!!!. Good ketch Ian. So if he is trying to balance it on all three wheels he will need a ton of lead up front due to the gear being too far forward. Need feedback from Inverted to verify as the picture is still hard to see. EDIT: Went back and checked the plans again and it's still 2 5/8 which is behind the spar.

LAST EDITED ON May-14-04 AT 10:30 PM (CDT)
 
By the looks of the first picture, he has the gear mounted too far forward. My fix.----Lose the nose gear,swap wing gear side for side, bend more forward if needed, install tail wheel. Go have fun flying your new tial dragger.

I AGREE!!!

I concur. Dump the front wheel and add a tail wheel. Add fuel, fly, repeat

The following is as per Brodak kit plans:
Nose gear position is exactly as per plans. Good!
The CG should be 1/4" BEHIND the main spar. If it's forward of the spar, lighten the nose.
If the plane does not sit level once CG is located in correct place, bend the main landing gear BACK.

Sorry to be brief.

I just looked at the pictures again. Is it just me or is the main gear wheels touch the ground IN FRONT of the main spar!? Bad idea.

The main gear wires are bent in such a way that the wheels should touch the ground roughly 1/2 inch BEHIND the main spar.
Just swap left and right gear legs and that should do it.

Back to work...