How to Make the Omniwing Zeta Paper Airplane

The Omniwing Zeta (or simply Zeta) is a refined variant of the popular Advanced Omniwing flying wing paper airplane by menamiketrx of YouTube, meant to be fast, long range and stealthy. While the Zeta does retain a good portion of its predecessor's features, it also integrates new building techniques that enable easier construction and better performance.

Development

Development of the Zeta began after I revisited the Advanced Omniwing in November 2015. As it had been some time since I'd last made an Advanced Omniwing, I had forgotten just how much imprecision there was in the design during construction. Knowing that approximation can sometimes lead to problems if certain things are not estimated correctly, I decided to redesign the aircraft to standardize construction. In addition, because of previous experiences with the Advanced Omniwings, I decided I would also integrate vertical stabilizers into the design to improve stability. As I had previously found that six vertical stabilizers provided sufficient yaw stability on unmodified Advanced Omniwings, I believed that this number would be sufficient for the Zeta as well. With these two construction goals in mind, I began prototype work on "the Zeta project."

The first Zeta prototype ("YF3-6A") was made by myself over several hours' time with design decisions made as production progressed. Its general layout was very much like that of an unmodified Advanced Omniwing but its internal structural design became substantially different. Unlike the standard Advanced Omniwing, the Zeta's longerons and spars are one modular assembly composed of several standardized parts, secured into the airframe at key points. This design change offered the advantage of enabling easier construction by allowing individual parts for these structures to be made and handled separately for a long period of time before being put together and then fitted to the wings in a larger group. Eventually, I modified the internal structures of the design to give it better strength with only a very meager amount of weight being added. The design with those modifications excelled and was approved for publication as the F3-6C.

TAA USAF Designation: F3-6C

Required:

8 Pieces of 8.5 inch by 11 inch Paper

2 Post-Its (3 inch by 3 inch)

Tape

Scissors

Ruler

Pencil

With two pieces of 8.5 by 11 inch paper, align both over top of one another flush. Apply tape to one of the width sides to connect the two as shown. (Photographs 1 to 2)

Measure 3 inches from the opposite corner along the length side of the paper and make a mark. Along the edge of the paper, measure 2 inches from the same corner along the width and make a mark as pictured. After doing this, make a diagonal line between these marks and cut while both paper are aligned over top of one another. This should result in the papers being symmetrical about the taped center line. (Photographs 3 to 7)

Along the width, measure 0.5 inches back from the mark made previously and make another mark. Along the length, measure 0.75 inches. Fold down the paper so the crease connects these two marks and repeat on the other side. (Photographs 8 to 13)

Repeating the process, measure 1 inch back from the crease along the width and mark and measure 0.625 inches from the crease along the length edge and make a mark. Once again, connect the new marks with a diagonal fold. (Photographs 14 to 18)

After completing the last fold, measure 0.625 inches from the crease along the width and mark; then measure 1 inch down from the crease along the length and make a mark. Make another diagonal fold to connect these two marks and repeat on the other side. (Photographs 19 to 23)

After completing the last fold, measure 0.5 inches from the crease along the width and mark; then measure 2 inches down from the crease along the length and make a mark. Make a fold to connect these two marks and repeat on the other side. (Photographs 24 to 28)

After completing the last fold, fold between the forward corner of the taped center edge to the wingtip without creasing the existing folds again. (Photographs 29 to 31)

While the aircraft is folded in half along its taped center crease, measure 3 inches forward of the trailing edge at center crease and make a mark. Measure 1 inch forward of the trailing edge along the wingtip and make a mark. (Photographs 1 to 2)

Connect these marks with a diagonal line. Before cutting, apply a paper clip to the outer airfoil sections as shown to hold the wing sections together. Cut along the diagonal line and save the pieces of paper you cut off. These will become part of the aircraft's skin later (SK-1). (Photographs 3 to 5)

Measure 4 inches from the center crease along the trailing edge and make a mark. Measure a further 3 inches from this mark and make another mark. Parallel with the center crease, measure 0.375 inches inward from each mark and make lines to the trailing edge. From the outboard mark, measure 0.125 inches toward the inboard mark and make another mark as shown. Connect this new mark with the outboard line's inner end. Repeat this process on the other side. Do not make any cuts to any of these lines. (Photographs 6 to 13)

To make the Zeta's trim tabs, measure 0.375 inches forward of the trailing edge along the wingtip and make a mark on each side. Make no adjustments to the trim tabs at this point. (Photographs 14 to 15)

With another sheet of paper, fold the paper in half along its width and length to divide it into fourths. (Photographs 1 to 5)

Using one of these fourths, fold this piece into fourths as well. Fold it in half along the length and width, then fold the lengths into fourths and then over top of one another as pictured. Along the width half fold, make the crease more visible with a pencil marking. (This piece will now be identified as SS-1.) (Photographs 6 to 12)

Measure 0.75 inches inward from each side along the crease edge and make marks. Between these two marks, make a solid line. Continue over this length with the pencil until it goes through and makes a slit out of the solid line. (Photographs 13 to 22)

With another sheet of paper, fold the paper in half along its width and length to divide it into fourths. After folding the paper in half along its length, fold the creases that have resulted to divide the paper into eighths along its length. Cut it in half along the width half crease to produce two of the desired support parts. (These pieces will now be identified as SS-2.) (Photographs 1 to 12)

Along each of the SS-2 pieces, measure 0.5 inches from the corner along the side that is split open and make a mark. Make a diagonal line connecting this mark to the crease side's corner. Then cut the section outboard of the line away. These two pieces should have the cut edges mirror one another--they are left and right handed mark the left handed piece as SS-2L and the right handed piece as SS-2R. (Photographs 13 to 20)

Make a third SS-2 by using another sheet of paper, fold the paper in half along its width and length to divide it into fourths. After folding the paper in half along its length, fold the creases that have resulted to divide the paper into eighths along its length. Cut it in half along the width half crease to produce two of the desired support parts. One of the two pieces will be used as the SS-2C part, the other is surplus. At this stage, undo the last half fold so its angled edge is mirrored and mark this piece as SS-2C. (Photographs 21 to 39)

With a new sheet of paper, fold the paper in half along its width and length to divide it into fourths. After doing this, fold one of the length sides into the length center crease. After doing so, cut along the length-wise center crease. Keep the remaining paper below--this will become SS-4. (Photographs 1 to 7)

With this new piece, again fold these length sides into the center crease to create new fourth folds. Fold the fourths over top of one another flush and identify one of these sides as SS-3L and the other as SS-3R (place these markings next to the width half fold as shown). With this done, cut along the width half fold to bisect the paper. (Photographs 8 to 18)

On SS-3L, measure 2.25 inches from the side with the identifying mark on it along the open side of the paper. On SS-3R, measure 2.25 inches from the side with the identifying mark on it along the open side of the paper. (Photographs 19 to 20)

Using the half sheet of paper that was saved as noted in the previous step, fold the paper into halves along its length three times over, as was done with the SS-3 pieces in the previous step. (Photographs 1 to 5)

Use the extent remains of the width half fold from the paper's original fourth folding to identify the centerpoint; mark this line well enough that it is easily visible. (Photograph 6)

With another sheet of paper, fold the paper in half along its width and length to divide it into fourths. After folding the paper in half along its length, fold the creases that have resulted to divide the paper into eighths along its length. Cut it in half along the width half crease to produce two of the desired support parts. After doing this, fold the outer creases of each side into the center crease again. (Photographs 1 to 14)

Select which side will be forward part for each side and write the identification information on each as shown. On the creased side, measure 0.5 inches back from the forward edge and make a mark. On the open side, measure 0.3125 inches from the forward edge and make a mark. Connect these two marks with a diagonal line. Cut along these diagonal lines. (Photographs 15 to 23)

From the rear side opposite where you have made the previous marks and cuts, measure 2.25 inches forward along the creased side and make a mark. Measure 0.625 inches forward and make a mark. With the creased section laid out, unfolded in its halves, make a solid line connecting all of these two marks along the crease they sit on. Run the pencil between the two marks until the paper gives way in that section and the pencil breaks through. (Photographs 24 to 36)

Once this slit has been created in the SS-5 pieces, test that the SS-4 piece may slide through both of these slits. (Photograph 37)

To improve their fit on the aircraft, we must revisit and trim the SS-2C and SS-5 parts. (Photograph 1)

Begin with the SS-2C part by folding it along its center crease again. Measure 0.125 inches up the center crease from the trailing edge and make a mark. Along the outer edge, measure 0.125 inches up from the trailing edge and make a mark. Connect these two marks with a solid line perpendicular to the edges. With the line made, cut along it. You may discard the small bit you cut off. (Photographs 2 to 5)

On the creased edges of the SS-5s, measure 0.0625 inches up from the trailing edge and make a mark. On the open edges, measure 0.375 inches from the trailing edge and make a mark. Connect these two marks with a solid line. Cut along this solid line. Discard the small chunks you have separated. (Photographs 6 to 14)

Once again put the SS-4 piece through SS-5L/R and over SS-2 to confirm that the parts fit as designed. They should look as they do in the photograph if they are fitted properly. (Photographs 15 to 16)

Be sure to align properly and then tape SS-4 where it passes over SS-2C. After this, flip the assembly over and apply tape to the underside of the SS-2C piece to keep its own internal folds together. The spots to apply tape to achieve this effect are noted in the third photograph and shown in position in the fourth. After the underside of the SS-2C piece have been secured, similarly secured the SS-5L/R pieces by applying tape along the length they sit over SS-2C. (Photographs 1 to 5)

Once the underside flaps have been taken care of, tape the SS-5L/R flaps down on the upper side as well. After they are in place, tape the leading and trailing edges of the SS-2C piece closed as shown in the eighth to eleventh pictures. (Photographs 6 to 11)

Fit the SS-1 piece over the forward edge of this assembly once you have done all of the above. (Photographs 12 to 13)

Place the SS-2L and SS-2R pieces next to one another flush, open them and apply tape to their lower inner meeting point as shown in the third photograph. To enhance strength, flip the assembly over and apply tape to the opposite side of where you just applied tape for the previous instruction of this step. (Photographs 1 to 5)

Along the outer edges on each side, measure 0.0625 inches along the tips and trailing edges of both the SS-2L and SS-2R pieces. Cut off the paper behind these marks on each side after completing them. (Photographs 6 to 11)

Install the SS-3L assembly into the SS-2L piece by pushing the SS-3L pieces in to where the marks you previously made with the edge of SS-2L. Apply tape where designated in the photograph. Install the SS-3R assembly into the SS-2R piece by pushing the SS-3R pieces in to where the marks you previously made with the edge of SS-2R. Apply tape where designated in the photograph. (Photographs 12 to 15)

Bring the forward and rear structural assemblies together as shown. Apply tape along the leading edges of the rear assembly where shown in the second and third photographs. (Photographs 1 to 3)

To complete the assembly, tuck the trailing parts of the SS-2s into the SS-4 while the SS-4's own edges should be tucked into the SS-3s as shown in the fourth and fifth photographs. (Photographs 4 to 5)

Apply tape on the SS-2L/R pieces to the SS-5L/R pieces as shown in the seventh and eighth photographs. After doing this, fold the SS-1 piece forward and tape it down to secure it to the SS-2s. (Photographs 6 to 7)

Once you have completed this folding, you will need to apply tape where designated in the photographs. Once you have made all the necessary applications of tape, your Zeta's internal structure should look as it does in the last photograph. (Photographs 8 to 23)

Keep both skin pieces together and flush with one another when making these changes throughout this step.

Along the straight trailing edge, measure 0.75 inches upward from the center crease and make a mark. Then connect this mark with the meeting point of the leading edge and center crease with a diagonal line. Cut along this diagonal line and discard the small resultant triangles. (Photographs 1 to 5)

Along the swept leading edge, measure 3.75 inches inward from the outer tips and make a mark. Along the straight trailing edge, measure 5.5 inches from the outer tips and make a mark. Connect these two marks with a diagonal line. Cut along this diagonal line and discard the noted portions to complete the skins. (Photographs 6 to 9)

Align the two skin pieces over the leading edges of the structure as shown in the first two photographs. After this, apply four pieces of tape along the leading edge span of the skin, connecting it to the SS-2 pieces. In addition, the trailing edge should be taped down at the SS-2C/SS-5L joint. After repeating this on the other side, the skin is secured on its upper side properly. (Photographs 1 to 5)

To tape its underside properly, first pull the Zeta's skin under itself until it reaches its limits as shown in the eight and ninth photos. Apply tape as pictured where the skin overlaps with the SS-2/SS-3/SS-4 joints. (Photographs 6 to 12)

With the adhesive area of the Post-It facing toward you, measure the 3 inch Post-It and make a mark at every inch. From each of these marks, measure 0.75 inches inward before stopping. Make a perpendicular like that connects these lines. Above the previous lines make two lines 1 inch above the perpendicular line directly above the lines below the intersecting one. Make a second perpendicular line above the new 1 inch lines. (Photographs 1 to 5)

Along the second perpendicular line, measure 0.75 inches outwards on each side from the left line and make a mark. From each of these marks, make a diagonal line connecting the mark to the edges of the same cell its in. This will complete 4 of the 6 vertical stabilizers. (Photographs 6 to 14)

To make the last two stabilizers, you must make the two individual templates and make them so they are oriented correctly before they are cut. The tops of the fins are each 0.75 inches with the leading edge sweep being handed. (Photographs 15 to 19)

To prepare all fins for mounting, fold them at the perpendicular line closest to their adhesive. (Photograph 20)

Apply tape as shown to both sides of the center joint between the two sheets of the wing's surface. (Photographs 1 to 5)

Insert the completed internal structure assembly underneath the wing's airfoil folds. Tape the internal structure in at 3 points on each side, where indicated in the photographs. After this is done, the internal structure will be secured in at its front. (Photographs 6 to 10)

Next, tape along the trailing edges of the internal structure's skin panels as shown in the eleventh and twelfth photographs. After this is done, fold the wings' leading edges over the internal structure and tape them down as shown too. (Photographs 11 to 17)

With the leading edges taped, flip the airframe over and apply tape at the rear edge of the internal structure assembly and connect it with the airframe by folding the tape over the edge. (Photographs 18 to 20)

Gather the vertical stabilizers you made. The swept back edge of the fins faces forward on all. The adhesive portions of the inboard four fins should lie inboard when mounted. The adhesive portions of the outboard fins should sit outboard of the fins when mounted.

The outboard two stabilizers on each side should follow the elevator provision lines made earlier in step 3. The two stabilizers closest to the center of the aircraft should be inserted under the SS-5/SS-2C assembly with their adhesive portion tucked underneath as shown. (Photographs 21 to 25)

When all of the fins have been placed into position, fold them down so that you may flip the wing without damaging them. Flip the wing over and cut off the excess of the the middle fins on each side. (Photographs 26 to 27)

The airframe of your Omniwing Zeta is now completed, but for best performance you may need to make adjustments based on how you see your aircraft perform in test flights. Launches should be done at neutral or very slightly positive attitudes at moderate to high speeds.

If the aircraft pitches down/up or banks during its test flight, you may need to adjust the trim tabs at wingtips along the trailing edge. Bend them forward to the mark you made earlier but do not crease them. See the second to fifth photographs for pictures of these trim tabs. Adjust the setting of these trim tabs based on test flight performance.

If the trim tabs are insufficient, you can also make the elevators which provisions were made for earlier. (However, I have not found them necessary in the example of the Zeta I made.) Cut along the inboard solid lines on each side then the angled outboard solid line to complete the elevator cuts. Connect the two endpoints of these cuts with a crease. Deflection will be something that you must determine and adjust with test flights.

If yaw stability or performance is a concern, adjust the vertical stabilizers' trimming as necessary and shown to be needed in test flights.

Enjoy! (If you do enjoy the Zeta, I would appreciate your support in the DIY Summer Camp Contest which the aircraft is an entry in. :) )