Iron Dog

I applied my leading edge pieces slightly differently. Using thick CA, I applied the smallest piece at the root ot the panel, first. Next, I sanded it to the angle of the taper in the mid-section of the panel. Then, I applied the piece from rib W-4 to the tip.




Last, I tapered the mating edge of the middle leading edge piece where it glues to the outboard piece, just in front of rib W-4; and, glued this final piece to the rest of the panel.



My reasoning for completing it in this order was to increase the area of the glue joint, thus making it slightly stronger. Additionally, it slightly offsets the joint from that of the 1/8" LE doubler piece, so all the joints aren't in exactly the same spot, and therefore as likely to fail due to the stresses we subject these planes to. (This may not help much, but in my mind, every little bit helps.)

Iron Dog

Like Tim, I razor-planed the LE to the contour of the sheeting. (Only I can't get as close to the sheeting as Tim does without taking a chunk out of my sheeting, so knowing my "limitations", I didn't try to get too close, this time.)

Iron Dog

Find the laser-etched "tick" mark at the leading edge of both the root rib W1 (see picture in the previous post), and that of the tip rib W8.




Align the edge of a ruler with the the trailing edge (point) of the wing and the "tick" mark at the leading edge. Extend the "centerline" of the airfoil across the side leading edge, so it can be seen from the front. Do this at both the root and the tip.

Iron Dog

Center at W4, then glue, the 1/8" thick balsa filler piece to the leading edge. This piece will later be sanded in order to curve the joint at W4 and give the leading edge of the wing its distinctive "Yak curve."



Next, Tim demonstrates aligning a straight piece of 1/8 x 1/4" spruce (to use as a flexible straight-edge) with the airfoil "centerlines" detailed in the prior post. Trace along this straightedge with a pen or marker. This line is the line to contour the airfoil shape of the leading edge to.

FlyerInOKC

My Feedback: (6)

You guys are build fast and good! Nice job!

pjakew

My Feedback: (4)

Tim is a good builder, Ollie on the other hand....

Iron Dog

Yup. Now everyone knows why I make sure Tim is there to take me through the next step! ��

Iron Dog

Tim helps Eric to draw the airfoil front centerline on his panels.




I use a flexible, 18" metal ruler to more accurately place the line within the recessed section of the curved leading edge.

Iron Dog

Here are my wing panels, after razor-planing the leading edge. (I managed to accidentally "catch" the wing sheeting with the blade of the plane, and remove a section of it just behind the LE in the process, and will have to fill it, later.)

Iron Dog

Because this is a smaller (just over 400 square inches in wing area), lighter plane, the sheeting is only 1/16" thick. I felt it important to protect it, as much as possible, until the final sanding is completed, just prior to covering. Therefore, prior to rough-sanding the leading edge to its proper airfoiled shape, I applied painter's tape over the front edge of the sheeting.




Then, I began rough-sanding the LE. I rounded from the tape towards the line, trying not to remove the line. Despite my efforts, I had to redraw the line, in places, using my flexible rules and fine tip Sharpie.

tdstaf

My Feedback: (11)

tdstaf

My Feedback: (11)

YEP!!

Iron Dog

Tim now begins cutting out the ailerons of his wing panels. To cut through the sheeting, he uses a metal ruler and Exacto #11 knife.

Iron Dog

In order to cut through the ribs without risk of damaging them, I used a 12" hacksaw to perform the crosscut.

Iron Dog

The ailerons are now cut out of the wing panel. (Remember that this cut line is 1/4" ahead of the actual hinge line.)




Use a sanding block to lightly sand the rear edge of the panel flush. A 1/4" stick is then glued to this rear edge. While many feel that this is all that is needed for hinging the aileron, I would recommend gluing small blocks of appropriate thickness to fit between the top and bottom sheeting of the panel, where hinges are to be placed, to front of this 1/4" stick, first. This will increase the glue-surface for the hinges.


The 1/4" stick is glued to the panel.


Next, sand the 1/4" wide stick to the contour of the sheeting of the wing panel.

Iron Dog

Measure back 1/2" from the LE of the aileron and draw a line. Cut along this line, just as was done when originally cutting the aileron out of the wing panel.



(Remember: The aileron was cut 1/4" in front of the actual hinge line, and the trailing edge of the panel's hinge line was restored to its proper location when the 1/4" stick was glued-in during the last step. We measure back 1/2" now to compensate for that thickness, as well as the 1/4" strip that is also added to the LE of the aileron.)

With the aileron now removed from the panel, a razor-saw could alternatively be used to remove this section, if desired -- rather than the Exacto/hacksaw combination that was necessary, before. Either method works fine.

Iron Dog

Use a hinge centering tool to cut the hinge slots (or to drill 1/8" holes, if Robart Hingepoints are used) in the panel.




Align the 1/4" LE of the aileron with the TE of the panel, and transfer lines onto the LE in order to cut matching slots.




Using the centering tool, slot (or drill) matching hinge locations for the aileron.

Iron Dog

Trial-fit the aileron's LE onto the wing. Here, Tim lent me his rigid trial hinges. (I have to get some of these!)



Utilizing a sanding bar, sand the aileron's sheeting and ribs at the LE flush in preparation for gluing the 1/4 stick to it.

(As with the mating hinge-surface on the panel, measure the clearance between the top and bottom sheeting and glue small blocks to the rear edge of the 1/4" stick where the hinges are to be located, before glueing it to the aileron, if additional gluing surface is desired. Scrap tapered aileron stock serves this purpose well. If added, this extra material will need to be slotted/drilled, as well.)

Align the aileron with the LE piece to trial fit. When satisfied with the alignment and how everything fits, glue the LE piece to the aileron. (I found that I had cut my aileron at an angle, and had to sand some of the angle out, prior to gluing.)

Iron Dog

Again, to protect the thin sheeting, I placed painter's tape over the aileron sheeting when sanding the 1/4" LE of the aileron flush.

Iron Dog

We haven't been able to meet every week, but the last time we all got together, Tim brought me a present:



A set of my own Dummy Hinges for future building projects. THANKS Tim!


It is time to cut the aileron hatches:
The top of the wing's center section is still open, so that the ribs are still clearly visible. Align a ruler or other form of straight-edge with the inside edges of the ribs that form the bay around the aileron hatch location. Use this ruler and a pen to mark the location of the ribs on the trailing edge of each panel.

Iron Dog

Transfer these marks for the rib locations to the bottom of the panels.

Iron Dog

With the wing panel now reversed (the bottom of the wing panel is facing up), line up a T-square or small carpenter's square with the seam in the balsa sheeting alone the main spar. Align the other end of the square with the transfered marks indicating the inside edge of the ribs. Trace along the square to draw lines representing the location of the ribs.

Iron Dog

Place the aileron hatch in its desired location, roughly centered within the open bay. Trace lines on the bottom wing sheeting, completely around thefour sides of the hatch.


In these, and the preceeding couple of posts, I (Ollie) demonstrate the steps being detailed.

Iron Dog

So Jake, don't follow my examples, above. Do it as Eric and Tim demonstrate just for you, instead:


Eric (left) and Tim (right) draw the rib locations on the bottom sheeting of their panels, using the same methods detailed previously.

Iron Dog

Use a new (very sharp) #11 Exacto blade to trace around the plywood aileron hatch in multiple light cutting passes, until the sheeting is cleanly cut through, creating a cut-out for the hatch. Personally, I prefer to start with the cross-grain cuts, and finish with the cuts running closer to parallel with the grain.