[WingedFrog]

Using the Longeron Die, I got the curve OK but I am not sure it's a good idea to use the die to do the bend of 4 deg at the end. While I cannot figure out how to do the bending using VANs hammering method, I am afraid that the die will produce a curve in the last 6". Question to those who have been through this: is it a problem if the last 6" have a curve to make the 4 deg angle rather than being straight at an angle?

 

[DonFromTX]

I used the dies, that bend is not so much anyway. I placed the exact center of the die in exactly where the bend should be. Someone else had already figured that the deflection at the end of the longeron should be something like 7/16 or such, I used that as a guide rather than trying to measure the degrees of bend. Looks great to me so far, maybe when I attach the tailcone I will find differently, but I think not.

 

[rvbuilder2002]

The reason it describes in the manual to make a sharp concentrated bend, is because the fuselage shape requires this point in the longeron to have a Sharp Concentrated Bend.

If you choose to not do so, you will likely have a strange unintended bulge in the fuselage at that point,

 

[WingedFrog]

The reason it describes in the manual to make a sharp concentrated bend, is because the fuselage shape requires this point in the longeron to have a Sharp Concentrated Bend.

If you choose to not do so, you will likely have a strange unintended bulge in the fuselage at that point,

That would not be good!
I have a hard time figuring where this sharp bend is located under the skin and where this end of the longeron fits. Is it possible to make any correction/adjustment at installation time?
Any second advice out there among those who have been through it?

 

[NDrv8r]

sharp bend at end

The dies are made for the gentle bend around the cockpit, not the sharp down bend. The Hammer method is probably the best on that one.

 

[BigJohn]

Mark it accurately as specified in the plans. Put the short end in your vise, use the leverage of the long part to pull the bend into it. Tapping with the hammer as you pull will help make the bend sharp.

 

[WingedFrog]

Issue Clarified!

It could not be clearer now, specially coming from the die purveyor. Thanks for the tip, BigJohn, I will try your method.

 

[WingedFrog]

Finally done with Longerons

Thanks for the tip, BigJohn, I will try your method.

I have the feeling to have gone through an initiation after spending almost a week on this page 23-02.
BigJohn method worked well but what helped most is that I bought a 2 pounds rubber mallet. The one I was using was half that. The instructions are not very clear in this regard: what is a "Heavy Soft Face Hammer"?
Even so, I still discovered a few things: when you are finished bending the end to the right 4 deg. angle, you find out that the end is also bending downward. You then unbend it upward to find out that it is now bent only 3 deg... etc
This thing has a life of its own!
When eventually I was finished, it dawned on me that I had marked the beginning of these 6" ending the longeron with the initials of "Start Of Bend", the term used by VANs and I found it was very appropriate!

 

[Dave12]

Frog, if you remove the material on the top of the longeron it is very easy to chuck that last portion into a vice and put that 4 degree bend in it. DO NOT even consider disregarding this. I have seen at least one 12 that does not have this bend and it (imo) ruined an otherwise nice airplane. This defect jumps out at you when you see it.

 

[WingedFrog]

Right Dave!

Frog, if you remove the material on the top of the longeron it is very easy to chuck that last portion into a vice and put that 4 degree bend in it. DO NOT even consider disregarding this. I have seen at least one 12 that does not have this bend and it (imo) ruined an otherwise nice airplane. This defect jumps out at you when you see it.

Right Dave but too late for me! I still will remove this "optional for lighting" piece of the longeron's end as it may make it more pliable to adjust under the skin and avoid this dreadful bulge. Future builders take notice!