Building technique: Utilizing a Wing-Jig, Scale P-51 "Speed Wing"
07-22-2015, 03:07 PM
#51
Thread Starter
Installing the Leading Edge:
1. You will need two 1/8" x 1" x 36" pieces. Cut the first in the middle into two 18" pieces. Each of these will be the piece of the leading edge doubler, running from rib W4 to the tip.
1. You will need two 1/8" x 1" x 36" pieces. Cut the first in the middle into two 18" pieces. Each of these will be the piece of the leading edge doubler, running from rib W4 to the tip.
07-22-2015, 03:15 PM
#52
Thread Starter
2. The second 1/8" x 1" x 36" piece gets cut into two (rough-cut) 6" lengths and two (rough-cut) 2 1/4" lengths. These will be the pieces of the leading edge doubler, running from rib W2 to W4, and W1 to W2. If desired, draw a centerline with a fine tip Sharpie[SUP]®[/SUP] or similar marker.
3. Bevel the adjacent edges that will be mated and glued together at ribs W2 and W4. (The beveled edges will come together similar to a miter joint, but the bevels will be much less than 45 degrees.)
4. Trial fit, adjusting the degree of bevel until satisfied with the fit of the pieces. Center the beveled edge of the 18" piece of LE doubler stock with rib W4. Glue this edge to the outer half of rib W4’s thickness, while making sure that the rest of the doubler stock is approximately centered on all the remaining ribs out to the tip. The jig can be gently picked up and manipulated in order to use thin CA to glue the doubler to the ribs all the way to the tip; and, to the top sheeting. (Just be careful not to ding the trailing edge in the process.)
Optional step: Before gluing the next section of LE doubler, you could use the laser-cut “tick” mark on both rib W4 and on the tip rib as a guide to transfer the centerline of the airfoil to the front of the LE doubler. This would allow you to more accurately center the actual LE, when gluing it on in later steps.
This is my trial fitting. Note the degree of bevel at rib W4 and the approximated bevel indicated by the black line when trial fitting at rib W2.
5. Trim, bevel and install the [U]
3. Bevel the adjacent edges that will be mated and glued together at ribs W2 and W4. (The beveled edges will come together similar to a miter joint, but the bevels will be much less than 45 degrees.)
4. Trial fit, adjusting the degree of bevel until satisfied with the fit of the pieces. Center the beveled edge of the 18" piece of LE doubler stock with rib W4. Glue this edge to the outer half of rib W4’s thickness, while making sure that the rest of the doubler stock is approximately centered on all the remaining ribs out to the tip. The jig can be gently picked up and manipulated in order to use thin CA to glue the doubler to the ribs all the way to the tip; and, to the top sheeting. (Just be careful not to ding the trailing edge in the process.)
Optional step: Before gluing the next section of LE doubler, you could use the laser-cut “tick” mark on both rib W4 and on the tip rib as a guide to transfer the centerline of the airfoil to the front of the LE doubler. This would allow you to more accurately center the actual LE, when gluing it on in later steps.
This is my trial fitting. Note the degree of bevel at rib W4 and the approximated bevel indicated by the black line when trial fitting at rib W2.
5. Trim, bevel and install the [U]
Last edited by Iron Dog; 07-22-2015 at 04:42 PM.
07-22-2015, 04:11 PM
#54
Thread Starter
Installing the Leading Edge:
6. I chose to trial fit the 1/8" ply front wing bolt base at this point, and am glad I did. I accidentally sanded the leading edge of Rib W2 when flushing the sheeting with the ribs in Step 7G of the last section. Unfortunately, this introduced an angle, when the leading edge is designed to be straight where it meets the fuse between W1 and W2. (I will later glue a scrap piece of sheeting to the piece and sand so the leading edge is square to the ribs, again, prior to installing the final 3/8" x 1" leading edge.) I had to sand the ply wing bolt base to match. I also found that – largely due to the amount of dihedral – this piece is designed too long. (As the actual length needed would be determined by the amount of dihedral, and beings some builders may wish to take out varying amounts of dihedral, I think I will leave the ply bolt bases oversized, and have builders trim them, as necessary to suite their choices. In my mind, it would be better to have a piece that is too long and can be trimmed, than too short and end up out of luck.) To adjust mine for a proper fit, so the holes would still be centered, I measured and marked a centerline between the two holes; lined this up with the outside edge of Rib W1 and marked the excess length to be trimmed from the opposite end of the wing bolt base extending beyond the thickness of rib W2.
7. Before gluing the last LE doubler section to ribs W1, W2, and the front wing bolt base, I used the laser-cut “tick” mark as a guide to transfer the centerline of the airfoil to the front of the LE doubler at rib W2. This will be used to more accurately center the final actual LE.
6. I chose to trial fit the 1/8" ply front wing bolt base at this point, and am glad I did. I accidentally sanded the leading edge of Rib W2 when flushing the sheeting with the ribs in Step 7G of the last section. Unfortunately, this introduced an angle, when the leading edge is designed to be straight where it meets the fuse between W1 and W2. (I will later glue a scrap piece of sheeting to the piece and sand so the leading edge is square to the ribs, again, prior to installing the final 3/8" x 1" leading edge.) I had to sand the ply wing bolt base to match. I also found that – largely due to the amount of dihedral – this piece is designed too long. (As the actual length needed would be determined by the amount of dihedral, and beings some builders may wish to take out varying amounts of dihedral, I think I will leave the ply bolt bases oversized, and have builders trim them, as necessary to suite their choices. In my mind, it would be better to have a piece that is too long and can be trimmed, than too short and end up out of luck.) To adjust mine for a proper fit, so the holes would still be centered, I measured and marked a centerline between the two holes; lined this up with the outside edge of Rib W1 and marked the excess length to be trimmed from the opposite end of the wing bolt base extending beyond the thickness of rib W2.
7. Before gluing the last LE doubler section to ribs W1, W2, and the front wing bolt base, I used the laser-cut “tick” mark as a guide to transfer the centerline of the airfoil to the front of the LE doubler at rib W2. This will be used to more accurately center the final actual LE.
Last edited by Iron Dog; 07-22-2015 at 05:09 PM.
07-22-2015, 05:12 PM
#55
Thread Starter
Installing the Leading Edge:
8. Next, it is time for the actual leading edge to be installed. Instead of having to order the pre-rounded 3/8" x 1" leading edge piece, I opted to use two more easily obtainable 36" lengths of 1" x 3/4" x 3/4" triangle-stock as an alternate. When the sharp point of the leading edge is rounded, it will be 3/8" deep, as needed. Installation of the leading edge stock pretty closely mirrors that of the process for the leading edge doubler, detailed in Steps 1 – 5 (above).
8. Next, it is time for the actual leading edge to be installed. Instead of having to order the pre-rounded 3/8" x 1" leading edge piece, I opted to use two more easily obtainable 36" lengths of 1" x 3/4" x 3/4" triangle-stock as an alternate. When the sharp point of the leading edge is rounded, it will be 3/8" deep, as needed. Installation of the leading edge stock pretty closely mirrors that of the process for the leading edge doubler, detailed in Steps 1 – 5 (above).
Last edited by Iron Dog; 07-22-2015 at 05:29 PM.
07-22-2015, 05:39 PM
#56
Thread Starter
Marking the center of the LE, towards better alignment with the centerline of the airloil, when glued.
Leading edge doubler and leading edge glued from tip through rib W2.
Last edited by Iron Dog; 07-22-2015 at 05:47 PM.
07-22-2015, 06:13 PM
#58
Thread Starter
Preparing the Aileron/Flap Cut-outs:
1. Cut an aileron pattern from scrap sheet stock. Any material can be used; but, the leftover 36" long 3/32" angled sheeting piece that is 2 9/16" x 7/16" has the exact angle needed for the aileron, so this is what was used in the pictures that follow. Line-up the sheet stock over the plans to match the desired aileron length, based on the version being built and/or personal preferences. I used a square to cut the aileron pattern at a right angle to Spar B where the aileron meets the flap. As it has been claimed that vortices off the wing tip can cause aileron flutter at high speeds, I am choosing to have my aileron end at W9, rather than extend to the wing tip block. This will recess the aileron easily 1 1/2" from the tip. Accordingly, I lined up the razor saw with the inside edge of rib W9 (as drawn on the plans) to make the cut on the aileron pattern’s opposite end. When making your pattern, consider the thickness of the scrap stock that will later be used to fill the open ends of the wing and aileron.
1. Cut an aileron pattern from scrap sheet stock. Any material can be used; but, the leftover 36" long 3/32" angled sheeting piece that is 2 9/16" x 7/16" has the exact angle needed for the aileron, so this is what was used in the pictures that follow. Line-up the sheet stock over the plans to match the desired aileron length, based on the version being built and/or personal preferences. I used a square to cut the aileron pattern at a right angle to Spar B where the aileron meets the flap. As it has been claimed that vortices off the wing tip can cause aileron flutter at high speeds, I am choosing to have my aileron end at W9, rather than extend to the wing tip block. This will recess the aileron easily 1 1/2" from the tip. Accordingly, I lined up the razor saw with the inside edge of rib W9 (as drawn on the plans) to make the cut on the aileron pattern’s opposite end. When making your pattern, consider the thickness of the scrap stock that will later be used to fill the open ends of the wing and aileron.
07-22-2015, 06:55 PM
#59
Thread Starter
Preparing the Aileron/Flap Cut-outs:
2. Carefully flip the wing such that you are working from the inside. Insert two T-pins through the top wing sheeting along the inside edge at the very rear of Rib W9. (These pins approximate the kerf of the cut when the aileron is later cut out with a razor saw or hacksaw blade.) Place edge of the aileron pattern against the pins, while aligning the trailing edge with that of the wing sheeting. Place a number of T-pins around the perimeter of the aileron pattern. Be sure that all T-pins are inserted at 90-degree angles.
2. Carefully flip the wing such that you are working from the inside. Insert two T-pins through the top wing sheeting along the inside edge at the very rear of Rib W9. (These pins approximate the kerf of the cut when the aileron is later cut out with a razor saw or hacksaw blade.) Place edge of the aileron pattern against the pins, while aligning the trailing edge with that of the wing sheeting. Place a number of T-pins around the perimeter of the aileron pattern. Be sure that all T-pins are inserted at 90-degree angles.
07-22-2015, 07:13 PM
#60
Thread Starter
Preparing the Aileron/Flap Cut-outs:
3. Flip wing upright, and place aileron pattern on the outside of the wing sheeting, centered within the pin holes and aligned with the trailing edge of the wing sheeting. Use a fine point Sharpie marker or sharpened pencil to draw the outline of the aileron.
(Upon reflection, I probably should have left pins in, to act as a spacer, again compensating for the kerf of the eventual cut between the aileron and the 1/4 inch stock utilized in the next step.)
3. Flip wing upright, and place aileron pattern on the outside of the wing sheeting, centered within the pin holes and aligned with the trailing edge of the wing sheeting. Use a fine point Sharpie marker or sharpened pencil to draw the outline of the aileron.
(Upon reflection, I probably should have left pins in, to act as a spacer, again compensating for the kerf of the eventual cut between the aileron and the 1/4 inch stock utilized in the next step.)
07-22-2015, 07:26 PM
#61
Thread Starter
Preparing the Aileron/Flap Cut-outs:
4. Place a scrap piece of 1/4" stick along the leading edge of the aileron (or simply measure 1/4" beyond) and draw a line parallel to its leading edge. Measure 3/32" outside of the aileron pattern on the root side and draw a line parallel to this edge. (These will be the outside dimensions of the cuts when the aileron is eventually cut-out – trust me on this.)
5. If flaps are desired, the process is similar.
The top of the wing is now complete, and you are now ready to begin working on the bottom.
4. Place a scrap piece of 1/4" stick along the leading edge of the aileron (or simply measure 1/4" beyond) and draw a line parallel to its leading edge. Measure 3/32" outside of the aileron pattern on the root side and draw a line parallel to this edge. (These will be the outside dimensions of the cuts when the aileron is eventually cut-out – trust me on this.)
5. If flaps are desired, the process is similar.
The top of the wing is now complete, and you are now ready to begin working on the bottom.
Last edited by Iron Dog; 07-22-2015 at 07:38 PM.
07-23-2015, 06:52 PM
#62
Thread Starter
Sheeting the Bottom of the Wing:
1. Loosen the wing nuts of the wing jig and carefully pull out the wing. Flip the wing over “front-to-back” – leading edge over the trailing edge or vice-versa, so that you do NOT reverse sides of the root and tip of the wing – and then re-insert the jig rods into the Washout Cradle pieces. Try not to disturb/move anything, so that re-alignment is easier.
2. Re-align the wing so that Rib 1 is still the same distance from the aluminum upright of the wing jig and that the jig rods are again parallel to the jig base. I also found that my aluminum uprights were no longer perfectly square to the jig base, adjustment was necessary, as well. This was most likely caused by repeatedly flipping the entire assembly upside-down and back again. When satisfied with the alignment, of the jig and the wing panel, tighten the wing nuts. Please note that the “front” and “back markings on the two tip Washout Cradle pieces are now reversed, but that the tip airfoil is still angled forward properly in the cradles at negative 3-degrees, relative to the orientation of the wing.
1. Loosen the wing nuts of the wing jig and carefully pull out the wing. Flip the wing over “front-to-back” – leading edge over the trailing edge or vice-versa, so that you do NOT reverse sides of the root and tip of the wing – and then re-insert the jig rods into the Washout Cradle pieces. Try not to disturb/move anything, so that re-alignment is easier.
2. Re-align the wing so that Rib 1 is still the same distance from the aluminum upright of the wing jig and that the jig rods are again parallel to the jig base. I also found that my aluminum uprights were no longer perfectly square to the jig base, adjustment was necessary, as well. This was most likely caused by repeatedly flipping the entire assembly upside-down and back again. When satisfied with the alignment, of the jig and the wing panel, tighten the wing nuts. Please note that the “front” and “back markings on the two tip Washout Cradle pieces are now reversed, but that the tip airfoil is still angled forward properly in the cradles at negative 3-degrees, relative to the orientation of the wing.
07-23-2015, 07:09 PM
#63
Thread Starter
Sheeting the Bottom of the Wing:
3. Inspect the bottom of the wing for any excessive thin CA “drips” that may have pooled on the bottom of the wing. I found a drip where the Spar, rib, and shear web meet, where I got a little excessive with the amount of glue I used. I used a high-speed Dremel with a buffing pad to remove this CA. (I prefer this technique of using the heat generated by friction to melt and spin away the glue, over using an abrasive that tends to remove the soft balsa rather than the hardened adhesive.
4. Install the rear wing bolt base:
a. Draw a centerline on the rear 1/8" birch ply wing bolt base. Insert and glue the wing bolt base with the centerline to the outside of rib W1. Ensure it is square to W1, as any angling or twisting may cause alignment difficulties when gluing the wing panels together, later. (Scrap tri-stock or other material may be used to reinforce the glue joint, if desired. Just ensure that material does not protrude beyond the curvature of the outline of the airfoil.)
b. I had a 3/16" x 1/4" piece of stick balsa handy, and cut off a couple lengths 1/2" or larger off. I beveled both, on one end, to approximate the angle of the airfoil – one on the thicker 1/4"-wide side, and the other on the thinner 3/16"-wide side. From the front, I slid these between the wing bolt base and the top sheeting and thin-CA’d them in place, just outside the diameter of the hole. This should serve to give a little extra support to the wing bolt base and ribs W1 and W2, better guarding against cracks if the wing bolts are accidentally over-tightened
3. Inspect the bottom of the wing for any excessive thin CA “drips” that may have pooled on the bottom of the wing. I found a drip where the Spar, rib, and shear web meet, where I got a little excessive with the amount of glue I used. I used a high-speed Dremel with a buffing pad to remove this CA. (I prefer this technique of using the heat generated by friction to melt and spin away the glue, over using an abrasive that tends to remove the soft balsa rather than the hardened adhesive.
4. Install the rear wing bolt base:
a. Draw a centerline on the rear 1/8" birch ply wing bolt base. Insert and glue the wing bolt base with the centerline to the outside of rib W1. Ensure it is square to W1, as any angling or twisting may cause alignment difficulties when gluing the wing panels together, later. (Scrap tri-stock or other material may be used to reinforce the glue joint, if desired. Just ensure that material does not protrude beyond the curvature of the outline of the airfoil.)
b. I had a 3/16" x 1/4" piece of stick balsa handy, and cut off a couple lengths 1/2" or larger off. I beveled both, on one end, to approximate the angle of the airfoil – one on the thicker 1/4"-wide side, and the other on the thinner 3/16"-wide side. From the front, I slid these between the wing bolt base and the top sheeting and thin-CA’d them in place, just outside the diameter of the hole. This should serve to give a little extra support to the wing bolt base and ribs W1 and W2, better guarding against cracks if the wing bolts are accidentally over-tightened
Last edited by Iron Dog; 07-23-2015 at 07:35 PM.
12-28-2015, 03:40 PM
#64
Thread Starter
Installing the Aileron servos:
Normally, servo wires would be run through the wing root to the desired location of the aileron servo. The bottom of the wing would be sheeted, and the hatch-cover would be set in the desired location. Then the cover's dimensions would be traced around, and the sheeting would be cut away to make the aileron hatch, as well as for clearance for the cover. The hatch mounts would be glued to the underside of the sheeting, and holes drilled to secure the cover to these mounts.
But of course, it can't be that simple, this time. I chose to use the Hobby People Hi-torque Thin-wing Digital Servo in this version of my wing. This is a larger servo than what I used on the initial prototype, but I wanted this wing to be Gold-class-capable, so felt it was necessary. It is a very snug fit; but, upon a quick trial-fit, I found that this servo does fit as needed, but would require some modifications to the original design to avoid having to cut into the carbon fiber spar. (If not using a similar sized servo, or the rear carbon spar, this is not an issue.)
The most significant modification I found necessary was that with this particular servo -- and wishing to keep the carbon fiber spar full-length, I needed a bigger aileron hatch cover/door, and would not be able to use the laser-cut doors that came standard in the kit, as I did with my initial (Silver-class)wing utilizing a smaller servo. I grabbed a piece of 3/32" thick plywood (this matches the thickness of my wing sheeting) and cut two new covers. The covers are 3" wide (also matching the width of the center piece of the bottom wing sheeting to be used when later sheeting the bottom of the wing) x 3 1/8" in length.
These are all the aileron hatch pieces, including the original lasercut cover (left), which will not now be used in this particular install. Beings the hatch mounts will not be glued to the underside of the wing sheeting,some small tri-stock is cut to the length of these pieces and will used to reinforce the to glue-bond of the hatch mounts to the ribs, instead.
Normally, servo wires would be run through the wing root to the desired location of the aileron servo. The bottom of the wing would be sheeted, and the hatch-cover would be set in the desired location. Then the cover's dimensions would be traced around, and the sheeting would be cut away to make the aileron hatch, as well as for clearance for the cover. The hatch mounts would be glued to the underside of the sheeting, and holes drilled to secure the cover to these mounts.
But of course, it can't be that simple, this time. I chose to use the Hobby People Hi-torque Thin-wing Digital Servo in this version of my wing. This is a larger servo than what I used on the initial prototype, but I wanted this wing to be Gold-class-capable, so felt it was necessary. It is a very snug fit; but, upon a quick trial-fit, I found that this servo does fit as needed, but would require some modifications to the original design to avoid having to cut into the carbon fiber spar. (If not using a similar sized servo, or the rear carbon spar, this is not an issue.)
The most significant modification I found necessary was that with this particular servo -- and wishing to keep the carbon fiber spar full-length, I needed a bigger aileron hatch cover/door, and would not be able to use the laser-cut doors that came standard in the kit, as I did with my initial (Silver-class)wing utilizing a smaller servo. I grabbed a piece of 3/32" thick plywood (this matches the thickness of my wing sheeting) and cut two new covers. The covers are 3" wide (also matching the width of the center piece of the bottom wing sheeting to be used when later sheeting the bottom of the wing) x 3 1/8" in length.
These are all the aileron hatch pieces, including the original lasercut cover (left), which will not now be used in this particular install. Beings the hatch mounts will not be glued to the underside of the wing sheeting,some small tri-stock is cut to the length of these pieces and will used to reinforce the to glue-bond of the hatch mounts to the ribs, instead.
12-28-2015, 03:50 PM
#65
Thread Starter
Tri-stock is glued with medium CA to the hatch mount rails. Rails are trial fitted against the wing ribs in the desired bay of the wing for your chosen aileron location. I found it necessary to use a Dremel sanding drum to sand away a section of the tri-stock to make clearance around the rear carbon fiber rod, before gluing the rails in.
When satisified with the fit, glue the mount rails and tri-stock in-place, flush with the tops of the wing ribs.
When satisified with the fit, glue the mount rails and tri-stock in-place, flush with the tops of the wing ribs.
12-28-2015, 04:11 PM
#66
Thread Starter
Next, I made a plywood mounting bracket for my servo to mount directly to the hatch cover.
I am aware of my reputation for overbuilding, but I have yet to have any structural failures in any race plane I have ever built, so my methods (though potentially "overkill") haven't failed me, yet. With this in mind, I chose to thoroughly secure this bracket to the cover by drilling some additional holes though both the cover and the bracket and thin CA-ing in short lengths of toothpicks. Essentially, dowel-jointing the entire structure.
Remove the servo; cut the protruding length of dowels (toothpicks); sand them flush with the surface of the hatch cover and mounting bracket; then, using a narrow diameter Dremel sanding drum, remove the desired materail for clearance around the servo output arm.
The four dark circles are the dowels, now sanded flush. I also had to sand/grind the tips of the servo mounting screws flush with the cover to keep them from protruding (silver colored circles).
I am aware of my reputation for overbuilding, but I have yet to have any structural failures in any race plane I have ever built, so my methods (though potentially "overkill") haven't failed me, yet. With this in mind, I chose to thoroughly secure this bracket to the cover by drilling some additional holes though both the cover and the bracket and thin CA-ing in short lengths of toothpicks. Essentially, dowel-jointing the entire structure.
Remove the servo; cut the protruding length of dowels (toothpicks); sand them flush with the surface of the hatch cover and mounting bracket; then, using a narrow diameter Dremel sanding drum, remove the desired materail for clearance around the servo output arm.
The four dark circles are the dowels, now sanded flush. I also had to sand/grind the tips of the servo mounting screws flush with the cover to keep them from protruding (silver colored circles).
12-28-2015, 05:27 PM
#67
Thread Starter
Sheeting the bottom of the wing:
Prepare one of the four beveled trailing edge pieces that was cut back in Step 1 of the "Sheeting the Top of the Wing" section (Post # 20) for gluing to the bottom of the wing panel. Trial fit it directly above the matching top piece of sheeting, and mark each rib at the leading edge of this sheet.
Away from the rest of the wing panel, mist the beveled side of the sheeting with accelerator. Apply a bead of medium CA along the rear section of the ribs behind each of these marks, as well as along the trailing beveled edge of the top sheeting. Carefully but quickly line up the sheeting and depress. As stated before, it is important to pinch it together, rather than press down on the entire assembly and risk introducing a warp.
Back in prior posts, I instructed that scrap pieces cut from 4" and 6" wide pieces of 3/32" sheeting should be set aside, and would likely become useful when finishing the remainder of the wing sheeting. I found that they definitely were. You might remember the scrap angled length from the 6" wide sheet pictured below . . .
. . . Its position was adjusted for optimum fit between the trailing edge piece installed in the last step, and so that the leading edge would line up with the desired location of the aileron hatch. When satisfied with the alignment, mark and glue it in a similar manner as the trailing edge sheeting was just glued.
Line up the hatch cover with the front edge of this sheeting (with the 3" length running from front towards the rear) and mount the aileron hatch cover to the mounting rails installed in the prior section. Ideally, the leading edge of this hatch would extend only to the midpoint of the spar, allowing the matching 3" wide center sheeting section to glue to the back half of the spar, and the next section of sheeting the ability to be glued to the front half of the spar. (As I came to this realization after these pictures were taken, I wil have to trim mine accordingly by an 1/8", later, before final installation.)
Prepare one of the four beveled trailing edge pieces that was cut back in Step 1 of the "Sheeting the Top of the Wing" section (Post # 20) for gluing to the bottom of the wing panel. Trial fit it directly above the matching top piece of sheeting, and mark each rib at the leading edge of this sheet.
Away from the rest of the wing panel, mist the beveled side of the sheeting with accelerator. Apply a bead of medium CA along the rear section of the ribs behind each of these marks, as well as along the trailing beveled edge of the top sheeting. Carefully but quickly line up the sheeting and depress. As stated before, it is important to pinch it together, rather than press down on the entire assembly and risk introducing a warp.
Back in prior posts, I instructed that scrap pieces cut from 4" and 6" wide pieces of 3/32" sheeting should be set aside, and would likely become useful when finishing the remainder of the wing sheeting. I found that they definitely were. You might remember the scrap angled length from the 6" wide sheet pictured below . . .
. . . Its position was adjusted for optimum fit between the trailing edge piece installed in the last step, and so that the leading edge would line up with the desired location of the aileron hatch. When satisfied with the alignment, mark and glue it in a similar manner as the trailing edge sheeting was just glued.
Line up the hatch cover with the front edge of this sheeting (with the 3" length running from front towards the rear) and mount the aileron hatch cover to the mounting rails installed in the prior section. Ideally, the leading edge of this hatch would extend only to the midpoint of the spar, allowing the matching 3" wide center sheeting section to glue to the back half of the spar, and the next section of sheeting the ability to be glued to the front half of the spar. (As I came to this realization after these pictures were taken, I wil have to trim mine accordingly by an 1/8", later, before final installation.)
Last edited by Iron Dog; 12-28-2015 at 06:11 PM.
12-28-2015, 06:18 PM
#68
Thread Starter
Trial fit a 3" wide 3/32" sheeting piece from the side of the aileron hatch cover towards the root. Leave a slight overhang at Rib 1 and trim the exess. From this excess, extend the sheeting along the opposite side of the hatch cover towards the tip. Again, leave a slight overhang and trim the excess. (Aside from the small outside piece at the tip, I chose not to glue these center wing sheeting pieces in yet, as they give access to the bays that the aileron and retract wires will run through, and I have yet to receive- and therefore be able to install- my retracts. (Ideally, these sheeting pieces extend forward only to the rear half of the spar.)
Last edited by Iron Dog; 12-28-2015 at 06:23 PM.
12-28-2015, 07:23 PM
#69
Thread Starter
This is the sheeting that is glued-in at this point:
The scrap from trailing edge piece was used for the leading edge piece that spans from W4 to the tip. It had to be sanded slightly, to fit.
Other miscellaneous scrap pieces were assembled to fill in the angled leading-edge section spanning between W1 - W4, and glued together, form one final leading edge piece (as shown in front of the panel in the first picture, above).
These were trial-fit, marked, then sanded as necessary for a perfect fit between the leading edge and the center-sheeting piece.
In the picture above, I measured the distance back from the LE and marked the approximate center between the retract mount rails. I marked this point on the sheeting with a black dot.
The scrap from trailing edge piece was used for the leading edge piece that spans from W4 to the tip. It had to be sanded slightly, to fit.
Other miscellaneous scrap pieces were assembled to fill in the angled leading-edge section spanning between W1 - W4, and glued together, form one final leading edge piece (as shown in front of the panel in the first picture, above).
These were trial-fit, marked, then sanded as necessary for a perfect fit between the leading edge and the center-sheeting piece.
In the picture above, I measured the distance back from the LE and marked the approximate center between the retract mount rails. I marked this point on the sheeting with a black dot.
Last edited by Iron Dog; 12-28-2015 at 07:35 PM.
12-28-2015, 08:11 PM
#70
Thread Starter
I used a piece of sharpened brass tubing to cut a couple holes in the sheeting at the mark for the center of the retracts. This will allow access to a small Exacto saw blade or Dremel sanding drum later, when I wish to trim sheeting flush to the installation of the retracts.
