New Member - Potential Builder

[lake_harley]

I've had Legal Eagle plans for a few years, but never started construction of one. Lately, I've been looking through the plans again considering my next potential project. I have a few "starter" questions on Legal Eagle construction.....the kind of details that get me thinking. I'm currently finishing up a MiniMAX and it's in the "final assembly" stage right now, so my "next project" itch is really flaring up.

When building the fuselage, are the lower longerons first heated to bend them together while they're still flat on the building table, and then heated a second time to bring them up to the proper height to the tail post? It seems like one would have to have a second set of hands and eyes to get them brought together and bent up to the proper height all at once, while keeping the alignment with the centerline of the fuselage. Maybe I'm over-complicating the process? I've done a LOT of fabrication work, but have never worked 4130 to know if heating and cooling twice would have a negative effect on the tube's strength.

Next question......I know the Legal Eagle wing is for all intents and purposes the same as a MiniMAX wing, with one huge variation being the MiniMAX's full-span ailerons vs partial-span on the LE. I'd like to possibly use my MiniMAX wings (same spar spacing) to get a flying Legal Eagle fuselage and then would build the partial-span aileron Legal Eagle wings later. If I were using cables for the ailerons I'd have to come up with a different cable routing plan, but I'm wondering if anyone has ever done full-span ailerons and used control push-pull rods instead of cables. I did find one build log that replaced the elevator cables with a control rod, and I'm thinking aileron control rods could be adapted too. I'd have to open up my wings enough to install a different contol horn on my ailerons, but that wouldn't be a show stopper. 

The wonderful article in EAA's "Experimenter" is what got me thinking Legal Eagle again, and the thought of building one is growing stronger.

Thanks, in advance.

Lynn

[Steve]

I've had Legal Eagle plans for a few years, but never started construction of one. Lately, I've been looking through the plans again considering my next potential project. I have a few "starter" questions on Legal Eagle construction.....the kind of details that get me thinking. I'm currently finishing up a MiniMAX and it's in the "final assembly" stage right now, so my "next project" itch is really flaring up.

When building the fuselage, are the lower longerons first heated to bend them together while they're still flat on the building table, and then heated a second time to bring them up to the proper height to the tail post? It seems like one would have to have a second set of hands and eyes to get them brought together and bent up to the proper height all at once, while keeping the alignment with the centerline of the fuselage. Maybe I'm over-complicating the process? I've done a LOT of fabrication work, but have never worked 4130 to know if heating and cooling twice would have a negative effect on the tube's strength.

Next question......I know the Legal Eagle wing is for all intents and purposes the same as a MiniMAX wing, with one huge variation being the MiniMAX's full-span ailerons vs partial-span on the LE. I'd like to possibly use my MiniMAX wings (same spar spacing) to get a flying Legal Eagle fuselage and then would build the partial-span aileron Legal Eagle wings later. If I were using cables for the ailerons I'd have to come up with a different cable routing plan, but I'm wondering if anyone has ever done full-span ailerons and used control push-pull rods instead of cables. I did find one build log that replaced the elevator cables with a control rod, and I'm thinking aileron control rods could be adapted too. I'd have to open up my wings enough to install a different contol horn on my ailerons, but that wouldn't be a show stopper.

The wonderful article in EAA's "Experimenter" is what got me thinking Legal Eagle again, and the thought of building one is growing stronger.

Thanks, in advance.

Lynn

Lynn,
If you plan to be part 103 some weighing now would be prudent: http://www.angoraaffaire.com/leu/whatdoesitweigh_.htm

I bent the fus sta 3 cold - broke one tube when I tried it at sta 2 - finger patched it... You are over thinking the 4130 tube work - there is a whole fus build on YouTube - https://www.youtube.com/user/LeagleEagleAirplane
Steve

[lake_harley]

Thanks for the reply, Steve. I have been quite weight conscious in my current build and would be on another. Regarding weight, I would expect the weight of the MM and the LE wings to be quite similar, not necessarily Lb. for Lb., but very close. By the "what's it weigh" list, I think the MM fuselage is a bit heavier than the LE.

I had already found the build series on you tube, but my STA. 3 bending question wasn't addressed. It magically went from straight tubes to being bent, but still flat on the table, from one video (#9, I think) to the next (#10), but there was no mention of heat/no heat. A friend of mine has a tubing bender for smaller dia. tube, so maybe I'd do the "flat" bend cold, with the bender, but use heat when the tail gets lifted. One way or another, I'm sure I can get it done, I just don't want to "overwork" or weaken the tubing in the process.

Thanks again for the reply.

Lynn

[Steve]

Thanks for the reply, Steve. I have been quite weight conscious in my current build and would be on another. Regarding weight, I would expect the weight of the MM and the LE wings to be quite similar, not necessarily Lb. for Lb., but very close. By the "what's it weigh" list, I think the MM fuselage is a bit heavier than the LE.

I had already found the build series on you tube, but my STA. 3 bending question wasn't addressed. It magically went from straight tubes to being bent, but still flat on the table, from one video (#9, I think) to the next (#10), but there was no mention of heat/no heat. A friend of mine has a tubing bender for smaller dia. tube, so maybe I'd do the "flat" bend cold, with the bender, but use heat when the tail gets lifted. One way or another, I'm sure I can get it done, I just don't want to "overwork" or weaken the tubing in the process.

Thanks again for the reply.

Lynn

Lynn:
Open the LE plans to (Text page 3)  left column mid way down Leonard hits the longeron tube bending process pretty hard - you'll run the risk of breaking a tube if you try the cold tooling...

I saw a set of High Max wings out in the desert that weighed in at 50 lbs a side - headed for a LE fus... Nobody out there cares too much - they take off from the street in front of the house & have a community road-grader to keep the washboard scraped out of it...
Steve

[lake_harley]

After a quick read through the instructions you pointed me to, I guess I'll have to admit to over-thinking the longeron bending process. Thanks.

Wow! 50# Hi-MAX wings? After reading that I just had to weigh my wings (1030 MiniMAX plans). I hadn't weighed one since they've been completed and covered. Steping on the scale with and without the wing and aileron, and deducting my weight, one wing came up to 31.8# including the aileron. That's covered and primed/painted with latex house paint (4 coats total). Even if the digital scale I used is off, that's lighter than I had hoped.

Lynn

[Will Weidner]

Not over thinking the bending process is good advice, because that's exactly what I tend to do.  To put my mind at ease, I made a little mini-cluster out of short pieces of tube.  Then, holding it in a vise, I heated it and bent it, so I could see how it worked.  I saw how much heat it took, and convinced myself the outside of the bend wouldn't break from the stretch, and the inside wouldn't crinkle.  If it did either of those things, I could modify the process until I got it right without risking some of the precious long lengths of tube.  I think until you do something once, your full of questions about the unknown.

[lake_harley]

Thanks, Will! Excellent advice. I agree, the "unknown" is an unsettling place. That's one of the great things about these discussion boards, there's always someone who's "been there - done that", and that is a big help.

Lynn

[Dan_]

and the inside wouldn't crinkle.  

If the inside of the bend does crinkle, Leonard says just weld it...

[mkj1928]

Thanks, Will! Excellent advice. I agree, the "unknown" is an unsettling place. That's one of the great things about these discussion boards, there's always someone who's "been there - done that", and that is a big help.

Lynn

The "Unknown" is a great place, possibly the best freedom we have. The "unknown" is what makes it worth doing, that's where the fun is. At its core, you either bend, cut. drill or weld pipe/tube. Try not to overthink it.