Pathfinder (previous tail heavy post)

After many weeks of whimpering over the excessive tail heavy plane I have. I decided to do whatever to fix the problem. I fixed the problem, but now new problem exists. I put four 4 oz. weights in the nose, and could probably use another 1/2 oz. to make nose fall slightly forward. The new problem is ,I believe its now to heavy to fly.
I had a reply from B Little. I may take you up on your offer and give it to you.

If what you say is literally true, that you put **16 ounces** of weight in the nose, you do indeed have an interesting problem.

Giving it away is obviously an option, but do you realize what Bill might do with such a mess? Cut the wing out of the fuselage and build a new model around it.

Might try this yourself.

Correction on the weight. I used three not four 4 oz. weights. I didnt mean to exaggerate. Just an honest mistake.

I've been reviewing your posts and you don't tell us where the cg is, but rather that it takes weight on the nose to put the nose gear on the ground.

Have you swapped the gear?
The kit affords you the ability to build as a tail dragger or trike. The mains are significantly further back when in the trike mode.

Mine works just fine as kitted.

See Ya

Thanks for reply. The landing gear are shaped to set behind the CG. They are mounted that way. The CG from plans is 2 1/2 from leading edge. With motor (46la) it is 4 1/2 inches behind leading edge.
I have 46LA with tongue muffler, 4 1/2 oz tank, Great Planes 2 inch spinner, APC 12x4 prop. But will have to use 11 inch for clearence. I would say normal use of paint used for covering. Foam core wings. I dont have years of experience with them, but they are light. I may e-mail Brodaks and check if he may have an answer. Thanks

Hi John
Don't give up just yet!

Can you post some pictures of your plane? Sometimes that can be helpful, as there may be something that could be very obvious to others who are familiar with the model.

Have you considered flying it like it is, without the additional 12 oz. of nose weight? Very short fuel load, just around and around for a lap or two? Might be worth a try, you never know. It beats breaking it up or giving it away without knowing!

Not much constructive help here, I'm afraid, but maybe the pictures might help.

Good luck with it - it's a GREAT PLANE!!
Mo

We have to be missing something here. My PF with a Tower 40, metal tank, Tru-Turn spinner, box-stock wood, Monokote wing and tail, Rustoleum on the fuse and tail balances within a 16th inch of the plan mark. Made no effort to build the tail light. Gordon said that many of the ones built around his area need a little weight in the tail, maybe 3/4 or one ounce. Can you post photos of the plane?

Inverted
I`m Gordan Delaney the designer of the Pathfinder. Most of the ones in my area has had to add tail weight.About 1/2 of an ounce. You could shorten the tail momment 1 inch.That could help alittle. Could you tell me what yours weights?

Gordy

Buy any chance are you missing a cresent wrench or a screw driver????

>Correction on the weight. I used three not four 4 oz.
>weights. I didnt mean to exaggerate. Just an honest mistake.

Could you post a photo of one of those 4 oz. weights?

The lead weights I use from SIG are ~1" square x ~1/8" thick, and they are 1/4 ounce.

So, I'm trying to imagine a total volume equivalent to 48 of these 1/4
ounce lead squares, for 12 ounces..

Is it **possible** that you are confusing a 1/4 oz. weight for 4 ounces?

12 ounces is (typically) more than a whole stunt engine (plus muffler in some cases). Something does not add up here. Pathfinders are not THAT tail heavy, are they?

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"The purpose of education is to replace an empty mind with an open one." -Malcom Forbes

>After many weeks of whimpering over the excessive tail heavy
>plane I have. I decided to do whatever to fix the problem. I
>fixed the problem, but now new problem exists. I put four 4
>oz. weights in the nose, and could probably use another 1/2
>oz. to make nose fall slightly forward. The new problem is
>,I believe its now to heavy to fly.

There's gotta be something else we are missing here. 12 or 16 oz of noseweight is an insane amount and there is something else going on - most likely, some sort of misunderstanding about where the CG is supposed to be.

I have to agree. Having to add 12 oz seems insane to me. I can't fathom what on earth could be going on to be THAT tail heavy

I think I know what is going on.

When I was a little kid I did not know anything about moment arms and all that. I balanced small rubber job by putting weight only slightly ahead of the balance point. I needed a lot and the made the airplane very heavy. There was no one around to show me the error of my ways.

Where did you put this 12 oz of lead? When adding balance weight it should be at the extreme end of the to get the best results and minimum lead required. It can be difficult on a profile, but find some room as close to the prop as possible.

If the lead is right on the nose, send in a picture.

I have to agree. My Pathfinder came out at 52 Oz due to an extra heavy coat of color dope. But, most of that went on the wing, and it does balance slightly behind (1/4") where it should. If the tank is empty, it will tip back on tail. But, with a full tank it sits nicely on the front wheel. The main gear are designed to rake back a bit. Are they oriented correctly?

I'm assuming that this is built from a Brodak kit. I can't imagine that the tail is that much to heavy. Quick mental math is telling me that the tail is 5-8 Oz to heavy. This doesn't really add up to me either.

BTW, even at 52 Oz, with a Max 40H engine, this plane flies like it's on rails! So far my best prop is a Zinger 12-4 cut down to 11-4. This seems to give much better line tension in maneuvers then a standard Zinger 11-4.

I've included some pictures of my pathfinder for comparison.

Inverted,
Why don`t you E-mil me at [email protected] and I can E-mail you. You still haven`t told us what the total weight is,without the nose weight.Give us the info we ask for and it will make it easier to help you.

Gordy

Hey John!

In all seriousness, I think I would attempt to fly the plane with a "normal" configuration first (ie, your LA, whatever prop gets ground clearence, spinner, etc.) You might try adding the factory OS R/C muffler, but if practable ditch the 12 ounces of weight in the nose for this test flight.

If the model looks anything like a Pathfinder at all, and you did not fabricate the tail out of solid fibreglass (and I know you didn't), then I submit it is IMPOSSIBLE for the model to be so far out of balance. Only with the nose and tail moments drastically altered, or some inconsistency in measureing the CG could there be a 12+ ounce discrepancy in balance. If I'm building from a kit or from plans, in point of fact, I never bother checking the CG before flying-I just adjust from wherever it came out to whatever flies good for me. I'd check only if deviating from the norms, eg putting on a very heavy engine where it called for a Fox 35, etc.

I think if you fly it in a normal configuration you'll see it flies okay. You may be somewhat tail heavy, but once you've flown it you'll be able to apply normal trimming procedures from there.

If you are still not sure, bring it by the field in Richmond some time-I'll test fly it. I'm certain I can get it up and down ok. Heck, if I wipe it out I'll give you my Pathfinder kit and some cores. Before you got into stunt I bought one of FE's planes, an A-6 Intruder Profile. This plane looked very cool but had a monster tail heavy problem-it had an impact wing and tail moment coupled with a flite streak nose moment. Hanging a Saito 72 on it MIGHT have gotten the CG in the right zip code, but nowhere near "on". Even with that CG, it would take off and track ok. The trouble is when you started maneuvers, as you had to be quick to apply opposite control to what your initial input was to keep it from swapping ends in midflight. If I could fly that job, I bet I can fly yours ok and see how it is.

Inverted,
Just wondering why you ask for help.But when we ask for info about the pathfinder you won`t respond to the questions we ask you.

Gordy

Gordon-I know who the guy is with the Pathfinder. I suspect he has not had a chance to get back to his computer, or the chance to go back and recheck some of the issues on the model. He's a good person.

Part of his problem is he lives in the sticks and fellow C/L fliers are hours away. Its hard to troubleshoot that way....

I know Inverted, also. As Steve said he is quite a bit removed, distance wise, from any other fliers and he's still learning the ropes having recently moved out of beginner. He's been to my house a couple times, and we have had a couple flying sessions together.
I would love to see the plane, in person, to just see what is going on! This might happen in the next two weeks.
He is a good guy.
Bill <><