Aileron Design and Building
#1
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Aileron Design and Building
Programs I am using… Auto Cad 2000 and Profili
For the diagonals on an aileron how do I figure out the length I need them? Do I measure the length of the long diagonal line and put that into profili for the right design, then just use the first couple inches to get the correct shape? I want to send out the plans to have them laser cut and want it as exact as I can, no flat spots in the ailerons.
Is it best to angle all the diagonals the same way after the control horn (red) so the aileron stays stiff because you are trying to twist it from a point load not a distributed load.
For the diagonals on an aileron how do I figure out the length I need them? Do I measure the length of the long diagonal line and put that into profili for the right design, then just use the first couple inches to get the correct shape? I want to send out the plans to have them laser cut and want it as exact as I can, no flat spots in the ailerons.
Is it best to angle all the diagonals the same way after the control horn (red) so the aileron stays stiff because you are trying to twist it from a point load not a distributed load.
#2
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RE: Aileron Design and Building
You are doing it the hard way. Been there, done that.
Iffn' you have ribs 1 though 10, with smallest number being the center. You need to use the original EXTERNAL profile of the lower numbered rib portion which the new aileron rib is adjacent to. Use the EXTERNAL, not the actual shape of the defined wooden rib.
The using Acad, measure the length on the diagonal as to finished shape. Measure the height of the overall surfaces on the external at the hinge area.
Create a new file in Acad named perhaps Rib 6A and draw a box to the two dimensions. The height and measured length. INSERT the edge shaped aileron piece, matching the point to one of the verticals of the box. Then vary the X dimension of the insert (Not the Y) to match the height of the box at the hinge point. Then TRIM to meet the box sides. OFFSET the thickness of the skin, like 1/16" or 3/32", and you then have the general shape of the aileron rib. Add in pivot holes, locking tabs, etc. and you are done. Overall cannot take more the 2 minutes to complete.
It is all easy using Acad now. You need to use this method when creating ribs on swept or tapered wings when the airfoil gets angled to perpendicular over the aileron. I have done lottsa of these and by your text and remarks you are missing some important points which is too great to elabourate upon here.
Wm.
Iffn' you have ribs 1 though 10, with smallest number being the center. You need to use the original EXTERNAL profile of the lower numbered rib portion which the new aileron rib is adjacent to. Use the EXTERNAL, not the actual shape of the defined wooden rib.
The using Acad, measure the length on the diagonal as to finished shape. Measure the height of the overall surfaces on the external at the hinge area.
Create a new file in Acad named perhaps Rib 6A and draw a box to the two dimensions. The height and measured length. INSERT the edge shaped aileron piece, matching the point to one of the verticals of the box. Then vary the X dimension of the insert (Not the Y) to match the height of the box at the hinge point. Then TRIM to meet the box sides. OFFSET the thickness of the skin, like 1/16" or 3/32", and you then have the general shape of the aileron rib. Add in pivot holes, locking tabs, etc. and you are done. Overall cannot take more the 2 minutes to complete.
It is all easy using Acad now. You need to use this method when creating ribs on swept or tapered wings when the airfoil gets angled to perpendicular over the aileron. I have done lottsa of these and by your text and remarks you are missing some important points which is too great to elabourate upon here.
Wm.
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RE: Aileron Design and Building
Also lay your servo flat so the arm sticks out the same way as the arm on the aileron. Build a tray between the ribs for the servo. Depending on the size of the plane you can either glue the servo to the tray or make a sub mounting that bolts to the servo then to the cross structure between the ribs. On some of the park models I've even seen the servo fit through a cut out in one rib. Cutting away most of the rib is not my idea of maintaining the marginal strength of park flyer wings.
I'm with Willian on using Acad for ALL of the rib profiles. I've not been able to get the various software packages to size the ribs and spars correctly. Especially getting the spars to say perpendicular.
I'm with Willian on using Acad for ALL of the rib profiles. I've not been able to get the various software packages to size the ribs and spars correctly. Especially getting the spars to say perpendicular.
#4
RE: Aileron Design and Building
Looking at your drawing, I would recomed that you also turn the servo square to the aileron or your linkage will bind. That is in addition to laying it flat.