Minimax wingtips?

[Shay King]

Does anybody know if the glass fibre wingtips sold by Minimax will fit the Legal Eagle XL wing?

[jrbirdman47]

And does that same person know what they weigh? (Wondering if the wing can handle the extra weight out there at the tip in an "increased G" situation)

[jrbirdman47]

OK- according to Team Mini Max site:

Fiberglass tips are 5 lbs.

Carbon fiber are 3.5 lbs.

So, 1 3/4 to 2 1/2 lbs added at the tip. Not sure the tradeoff in weight/ added stress is worth any aerodynamic benefits.

[Dan_]

If memory serves I think Scott Johnson tried them on his LE, but took them off.

[Chuck in Indiana]

FWIW, at the speeds we are talking.. I'd be *very* surprised if tip design made much difference. (shrug)

[Kamcoman77]

From what I've read, the differences in wing tip designs on a Legal Eagle affect the effectiveness of the ailerons, and not much else.

[Shay King]

Thanks for the replies guys,
It seems they will fit.
They will add weight without any guarantee of improved performance.
In my opinion they do look better than the standard flat end.
But then if I was into looks would I be building a Legal Eagle?

[Chuck in Indiana]

Thanks for the replies guys,
It seems they will fit.
They will add weight without any guarantee of improved performance.
In my opinion they do look better than the standard flat end.
But then if I was into looks would I be building a Legal Eagle?

Beauty is in the eye of the beerholder..

[kalazzerx]

For getting the look and ensure the fit I think I just build them myself.  I follow a gent on youtube that was doing the same on an avid - https://www.youtube.com/watch?v=ya3I8QaT2KU.  I would think it could be fairly easy to NOT have a good fit because there is some on the rib on the minimax just like on the LE's.  I was surprised they now sell the plans for minimax but I still have the plans when they were free and they do look the same size wise.

[Chuck in Indiana]

For getting the look and ensure the fit I think I just build them myself.  I follow a gent on youtube that was doing the same on an avid - .  I would think it could be fairly easy to NOT have a good fit because there is some on the rib on the minimax just like on the LE's.  I was surprised they now sell the plans for minimax but I still have the plans when they were free and they do look the same size wise.

Many years ago, I received a call to do a technical counselor inspection of a Mini Max, so I flew to an airport near him and had a look. It was built by a woodworker, and the workmanship was of the highest caliber.
Comma but.
I had to tell him that it was too heavy to fly. He had "beefed it up a little." He knew nothing about airplanes.  He asked me if it was all right to cut the prop off a few inches so it would have enough ground clearance.. That sort of thing. It was sad. He'd put a *lot* of work into it..

[jrbirdman47]

I was thinking that it added weight without any realized performance enhancement and that would be enough, but further thought that adding 2 or 3 pounds 13 feet out at the end of the wing is quite a lot of additional loading and stress in turbulence, landings, etc.

At work, we had plans to add winglets to our older planes to get the 2 or 3% increase in fuel efficiency, (When oil prices got pretty steep), but found that those who had done it had structural cracking issues. Comparing a 2.5 pound tip on a 250 pound airplane, (1% of empty weight) vs. 200 pound tip on a 97,000 pound airplane, (1/10 of 1%), and THAT one had structural issues. (Might be comparing apples and eagles, I don't know)

It just seemed to be adding considerable weight, relatively speaking, in an area where material was removed from the spar caps because there was no weight out there.

But they DO look nice!

[Chuck in Indiana]

John Monnet investigated Whittman tips. They did what was expected.. but.. took the airplane from aerobatic to normal category. (Yes, I'm an old Sonerai guy..) 

[Tom XL-7]

Joe Spenser used a simple fence. An aluminum sheet flat on the wingtip. Originally it was like an oversized rib Both above and below the wing but in the end it was cut down to be just on the below side.

[Chuck in Indiana]

Joe Spenser used a simple fence. An aluminum sheet flat on the wingtip. Originally it was like an oversized rib Both above and below the wing but in the end it was cut down to be just on the below side.

A fence is probably what I'll use.. if anything at all.

[Dan_]

John Monnet investigated Whittman tips. They did what was expected.. but.. took the airplane from aerobatic to normal category. (Yes, I'm an old Sonerai guy..) 

The original Wittman wings were flat bottomed Naca 4309.  Modifying the camber to flat made it easier to build and set the zero incidence. 

The span was 20' 11".  In the early 70s he added span to improve altitude performance and had to add 13/16" to the spar.  This necessitated a curve on the bottom so he ended up with 4309 on top and naca 0006 on the bottom but no triangle tips yet.

He tested the triangle tips on his olds V8 powered plane and saw a 25% decrease in sink rate.  The tips made their way onto all his airplanes including the VWitt racer.