Building the Affordaplane Part 38

[@Dlgeis]

To make a repeatable measure for something like the strut measurement the use of a set of pinch sticks and two rubber bands holders is really quick and simple. Make a few sets at the beginning of the project covering different lengths. They are also invaluable when checking for symmetrical measurements.

[@davidwhite2011]

Looks like another good place for saddle washers on the ends of the wing strut.

[@HomebuiltHELP]

That's an interesting idea, thanks!.... too late for me now as that would drastically change the steel straps.

[@freddiehoskins6658]

Interesting and informative. How many A planes have you flown ? Love the vids !

[@arthursoutham9046]

Hi Jon. It seems that my last suggestion went nowhere. I was suggesting that jig be made to set the dihedral very accuratly. the jig would be a large right angle triangle with a 3 deg included angle. secure the hypotemuse of the jig to the wing spar and a small level to the adjacent side. With the aircraft leveled in both axes jack up the wing till the level on the jig reads level. The attachments to the aircraft can be done with elastic cord, and depending on how wild you wish to go with the jig you could build the level in or attach it with the same cord. I would suggest that this jig be made of a very stable material such as aluminium or stiff plastic as you may be required to use it again some time in the future. Please excuse the lousy spelling. This was not a strong point of mine at school.

[@HomebuiltHELP]

Hi Arthur - I am not ignoring your suggestions - just cannot respond to them all each week. I can reply to specific questions on Patreon - that's why I set that up. The idea of a large triangular jig for setting dihedral is creative. The caveat of course is that all measurements for angles and leveling are done carefully - that is what trips up any method. Thanks for your suggestion.

[@sashagray3513]

I like the technique, but feel like that dimension should be part of the plan. I feel that, if you follow the plans the strut length can only be 1 correct length.

[@davepompea]

If all holes are drilled on a cnc machine then you are correct. But with hand marking and drilling, the tolerance / error buildup is such that you cannot do what you are suggesting. I know. I've done this with my own aircraft building.

[@riedjacobsen8620]

Will holes be deburred?

[@Dlgeis]

Hi I personally would debur any crucial hole I made in any hole made on an aircraft structure since these structures aren’t load tested I believe I would just make it a policy to debur all penetrations as those are the places that corrosion and cracking are most likely to begin.

[@peteranderson037]

Would it be possible to measure the length from the bottom of the wing spar at the wing attach point to the floor, add six inches, and then use that to measure how far from the floor the wing should be at the forward strut bolt?

[@riedjacobsen8620]

If the floor is level . . .

[@HomebuiltHELP]

And not just a level floor - but you would have to use a plumb bob to find where on the floor to measure from the wing attach point for an accurate measure. So - the answer is yes - if you take care of these important details!

[@JeffCurtisIflyHG]

not only does the floor need to be level but it can't have any hills or valleys. I know of one floor that was truly level and flat but the owner found the right builder and specified the level of flatness required for the floor. They wanted the flatness for doing race car alignments. One quick way to check is to pour a coffee cup of water on the floor. It should completely cover an entire garage bay with no puddles or dry spots. I know from experience that my garage and basement floors are not at all flat or level but you couldn't tell without testing. What you care about is that the wings have the right dihedral with respect to the airframe. Making the measurement directly avoids introducing other errors as compared to an indirect method involving other structures.

[@showlowwings]

I don't trust string level when I'm building the house , never mind on the aircraft, should use digital protractor or laser

[@winterhorse290]

one question, are you going to put bottom ribs on the wing before you cover them?

[@HomebuiltHELP]

Let's follow the plans on this one!

[@jordang1814]

Is there any sort of relaxing of the dihedral once the ladder support is removed?

[@HomebuiltHELP]

Yes, there will be small amount of change - not enough to be of any concern!

[@JeffCurtisIflyHG]

What you really care about is the dihedral while the wing is under the load of flying. In this case the wing will be pulling on the strut (to lift the plane) so if there is any play there will be more dihedral, not less.

[@prof.heinous191]

Just don't head back down south, Jon!

[@DwightEWilliams]

Snow! Just blasphemy, I tell you.