#11
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Tail Feathers
Whoops, I made a big mistake! I should have posted this build step before showing the Fuselage Prep one.
The reason why this is an important mistake? The Rudder needs to be dry fit before inserting the PSI Tube assembly. This protects the PSI tube from accidentally getting cut! Ok, now back to building... 1st photo shows the rudder parts already glued together. Make sure the front glue tabs are inside, not on the outside. Now I'm applying PVA glue, but it is best to use spray glue for these steps! If you use PVA like I am, be sure to place under a heavy flat object while the glue dries. If the Elevator or Rudder warps from using this glue, the wavy shape will cause excess drag/flight control issues when flying. The model will still fly, you just have to bend some of the control surfaces to compensate, which causes the drag, in other words the model won't go as high or as far if these don't warp! 2nd photo shows glue applied to the top, the bottom needs glued as well. BTW-Way too much glue-perfect for a warped Rudder, which is exactly what happened! 3rd photo shows a close-up of the glue tabs. This is where it is important to verify alignment of parts. If these are properly aligned, the rudder sits on the fuselage straighter and is easier to glue. The bottom edge of the Rudder needs to be aligned, not the tabs, the tabs in the next photo will be trimmed for the dry fit to the fuselage. 4th photo shows trimming the glue tabs to fit the fuselage slits. It is easier to trim these for length, than it is trimming the fuselage! 5th photo shows cutting the opening for the Elevator. Use a straight edge to do these cuts! Notice I don't cut all the way through the rudder to the front-bamboo skewer is pointing to show not to cut all the way! The thick dotted lines look like they go all of the way, but it is easier gluing the Elevator on if you don't cut the whole distance. 6th photo shows the dry fit to the fuselage. Notice how the rudder sits without any gaps underneath it, where it sits on the fuselage? 7th Photo shows initial step in gluing Elevator. Do it just like the Rudder to complete it. |
#12
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Wing Construction-Attaching to Fuselage Assembly
Time to build the wings and attach to the Fuselage.
To make the wings is really easy, but hard to make accurately. NOTES ON CONSTRUCTION: Be sure to score the fold line, if it is crooked, the leading edge will change the shape of the airfoil. After scoring, line the trailing edges up, holding the trailing edges to the table, fold the score line flat with your other hand. The wingtip rib should be laminated. Once glue is dry, bend the glue tabs. Do not bend them over the laminate. The laminate will be flush with the wingtip edge, by bending the tabs the other way, it is easier when gluing to keep it flush with the tip! Flush is important to keep the drag down. When gluing the rib into position, always glue the top and bottom at the same time. This is a symmetrical airfoil (equal on both sides), the only way to keep it this way is to do both sides at the same time. Put some small drops of glue on the front two tabs on the ribs. Slide it forward into the pocket created by the valley fold of the wingtip. Now pinch as shown in the photo below. After the glue sets it is possible to do all the other tabs at once. Just make sure the rib is flush with the edge. Sometimes the rib tries to twist, make sure it doesn't! Any excess wing skin sticking past the rib needs to be sanded off, to reduce drag. When attaching the wings to the fuselage. Insert the tabs into the slits. Once in position just run a bead of glue along the tabs/fuselage spots. You can also glue anywhere the wing touches the fuselage. Now about the angle to attach them at: -I insert them and give them a slight downward angle. 2deg is a good choice. This gives the model some stability when flying. -Or you can just insert them so that they are straight out. This makes it easier to construct. Which ever way you do them, make sure that both have the same angle by looking down the sides of the fuselage and visually checking the tips. Both should be level to each other. 1st photo shows the parts need to construct the wings. Blue side is the bottom on the NASA model. Notice how the rib glue tabs are bent. 2nd photo shows the gluing of the first 2-tabs Top & Bottom. 3rd photo shows the inside of the wing after the rib is first attached. 4th & 5th photos shows gluing the other tabs all at once and applying pressure to the Top & Bottom along the whole length. Be sure the rib is flush with the wingtip edges and not twisted. 6th photo shows the gluing of the trailing edge. Run a real thin bead of glue down the length of the trailing edge. Press and hold on a flat surface, then flip over and hold once again. Keep flipping back and forth to make sure the wing doesn't set with one side of wing at a different angle. 7th photo shows one of the wings ready to attach to the fuselage. Notice the airfoil shape at the wingroot side. (wingroot is the side of the wing that attaches to the fuselage). Now do the other wing. 8th photo shows the small Top gap between the wingroot and fuselage. This gap is to allow wing to angled down. 9th photo shows the bottom side with No Gap. 10th photo shows the wings and Fuselage assemblys ready for the Nacelles. Nacelles are next! |
#13
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Forming the Nacelles
Time to form the Nacelles.
These give the model strength. They form a "cantilever" type mount for the wings. This allows the wings to be made without the use of internal wing spars! They also support the Fuselage, adding strength to the front when the model performs a vertical landing pattern. Roll them just like doing the Fuselage & PSI tubes using a wood dowel or any method you prefer. To get them ready to attach to the model, a few things must be done as follows: 1st photo shows the bending back and forth of the glue tabs. Notice I try to show this by one side up, the other down. These tabs need to fold easy, if they don't, they act like a spring, forcing the Nacelle away from the fuselage while trying to glue in the next step/post! 2nd photo shows the nacelle ready to roll. Notice that the wing opening is Not cut out! 3rd Photo shows how the nacelles should look after rolling. 4th photo shows the wing opening cut and the forward tabs bent inward. These tabs create a very strong connection to the forward part of the wing, forming the cantilever mount where it is needed most! Now would be a good time to edge color the front of the nacelle, if you want to. This is the only edge coloring I do. 5th photo shows gluing the nacelle to the front air inlet. 6th photo shows a completed Nacelle, ready to be attached to the fuselage/wings. Attaching the Nacelles is next! |
#14
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Attaching Nacelles to Fuselage/Wing Assembly
This is the hardest thing you will do on this model! Once it is done, the rest of construction is easy and over in just a few minutes! This step however takes some time, gluing skill and quick hands!
When the actual gluing of the Nacelle to the Fuselage was happening, I could not take any photos. So, text will have to do. First dry fit the parts. Slide the Nacelle all of the way onto the wing. Press tight to the fuselage. Checking for fit now makes this much easier as it gives you an idea of what the final alignment of the Nacelle to Fuselage & Wing looks like. Glue tabs giving you any issues? You might have to fold them back and forth once again to loosen them up. NOTE: Do not apply any glue to the inside wing tabs yet! Wait until both nacelles have been attached and the glue has set. Apply glue to all of the tabs that touch the fuselage, this includes the air inlet ones at the front of the nacelle (curved ones). Be really careful to slide the nacelle onto the wings before touching the fuselage, if you don't, glue will get everywhere! Now press the nacelles tight to the fuselage, making sure they are snug to the wing and the wing is in the valley in the wing cut out. Make sure the wing and nacelle are tight! Not to tight to crush the wing. Check for a gap at the front of the nacelle under the air inlet area. Press tight to get rid of it if there is one. Check that the length has no gaps between fuselage side and nacelle. Now keep checking all of these areas as you keep holding the parts together while the glue sets. Keep checking! Check again and again. Don't leave your hands in one position too long, or gaps will form elsewhere. Make sure there are no gaps under the inlet or at the front part of the nacelle. Gaps here will cause massive drag issues. After glue sets, run a glue bead (fillet) down the top and bottom sides of nacelle/fuselage connection. Small bead but very important to aerodynamics of model! Set aside to dry. Allow bead to dry, if you don't, smearing glue is going to happen! Be careful because the model is almost done, this would be a bad time to smear glue! Now do the other side nacelle the same way. Make sure they both are lined up across from each other and that they aren't to much to the bottom or top sides. The wings usually hold them in the proper position, but sometimes they don't. After the glue completely sets on both, time to do the wing to Nacelle junction. Run a small bead of glue under the nacelle on the top of the wing skin. Now press the nacelle down and hold until glue sets. Once again a back and forth check while applying pressure to stop any gaps from happening. In one of the photos I show using a small bamboo skewer to apply pressure. This works great when mating these two surfaces. After the glue has set, you need to run another small bead down this junction for aerodynamics too. Once again allow bead to dry, if you don't, smearing glue is going to happen! Be careful because the model is almost done, this would be a bad time to smear glue! Roll the engine inlet cones, bend the tabs and get ready to glue them to the front of the nacelle. Notice that there is an alignment line in front of the nacelles; this is where these small cones line up. Just add glue and press/hold in place. 1st photo shows Nacelle attached to the fuselage. Notice the wing fit at the front. See the nacelle "tails" at the wing trailing edge? These help you pull the nacelle onto the wing tightly! 2nd photo air inlet glue fillet, to stop air from getting under the nacelle. 3rd photo shows applying the glue fillets to the fuselage/nacelle junction. Once both sides have been done it is time to glue the Nacelle to the wing. Run a small bead of glue on top of the wing, under the nacelle edge; press the nacelle down to meet the wing. 4th photo shows using a bamboo skewer to apply pressure as the glues sets when attaching the nacelle to the wing skin. 5th photo close-up showing more detail when using the bamboo skewer to apply pressure, don't use too much force or you could deform the wing skin. 6th photo shows rolling the inlet cone. 7th Photo shows the attached Nacelle & Inlet Cone. Once all glue has dried it is time to trim the nacelle tails even with the trailing edge of the wing. Be careful not to cut into the fuselage or wing. Next step deals with the final construction of the model. |
#15
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Final Assembly Steps
The model is almost ready for weight and balancing, but first lets add a couple of parts to complete it.
Glue the elevator to the Rudder as shown below. Use the centerline on the elevator to align it to the rudder. Make sure the Elevator Hinge line is to the front. If one side of the Elevator keeps rising while the glue sets, use a small weight (I used a wood dowel as shown in the photo below) to keep it down. Glue tailfeathers to model once they are set up. While they are drying in position, it is ok to do the canopy rolling/gluing, getting it ready for the last construction step. 1st photo shows gluing the Elevator to the Rudder. 2nd photo shows proper alignment of tail to fuselage (AutoCAD drawing). 3rd photo shows using a piece of wood dowel to hold the elevator level while the glue sets. Notice how the rudder is supported between a tape measure and a roll of tape-holding it vertical while glue sets. 4th photo shows attaching the Tailfeathers to the model. Make sure to apply glue to the model, getting it inside the slits for the Rudder glue tabs! 5th photo shows the rolled nosecone ready for gluing. 6th photo shows the Canopy alignment lines on the nosecone/collar assembly. Use the centerline to align canopy when gluing. 7th & 8th photos show applying pressure to the canopy as the glue sets. Apply pressure to the sides as well making sure there is an airtight seal all the way around the canopy. If there are any gaps, you will need to apply a glue fillet for aerodynamics, if the air gets under the canopy, it will cause a breaking action, and the model will drop like a rock! 9th photo shows airtight seal between canopy and nosecone. Last 2 photos show Top & Bottom of strong/lightweight finished model! Model is approximately: 25" long 11" wingspan Tail is 4-3/8" Tall Weight before balancing is 42.63 grams! Next step is weight and balancing model for flight! |
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#16
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Weight & Balancing For Flight
The weight & balance step is easy to do.
Sorry, about the overexposed photos! It was a bright day outside when I tried doing this. First thing is finding a place to hang the model. For these photos a weight rack was used, but an open doorway will work too. It is easy to double some sewing thread to hang model with. Just use common clear office type tape when doing this step. 1st photo shows model without any weight. It hangs nose high. 2nd photo shows some modeling clay lying on top of the nosecone to balance the model level. Clay is wrapped with some plastic cut from a grocery bag. I like to hang model slightly nose down. The Elevator can be bent for level flight, to compensate for this. 3rd photo shows another angle of model hanging level. 4th photo shows some clay on top of the piece of grocery bag. To install clay inside the nosecone, roll the clay into a small rolled cone shape, between your hands. Wrap with the plastic piece of grocery bag to stop the oil from staining the cardstock. 1) Push into the nosecone using a small piece of wood dowel. 2) Cut a 2" Length x 1/2" Wide scrap cardstock 3) Glue cardstock inside the nosecone, holding the clay in place so it can't move. Let dry. Model is ready to fly! Arlo said, "27-Black & White photos, with a paragraph on the back of each one". For this thread it would read, "With 27 paragraphs before each photo". BTW-Don't forget to glide test before the first Stomp Flight!!!! Hope you have fun building & Flying these Paper Stomp Rockets! This brings an end to the Hack, Cut, Fold, Glue and Stomp Thread... Best regards, Mike Bauer |
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