Rigging Aircraft with Tippet

[DrLaser]

Wings

Okay, with the right lengths of tippet, we'll start with the top wing - which usually has most of the "rat's nest" which you'll see in a bit. One length of tippet is threaded through the two outermost rigging holes at the wingtip. The hole is tiny, the tippet is very narrow, so those fine tweezers, and magnification, are essential. The figures show what's happening inside the wing (white) and outside the wing.



Now thread the next wire through the inner two holes.



You will now have a wire protruding from each of the four flying wire holes. The wires are strung from end-to-end to prevent stress on the paper and allow a long length of exposed tippet for the next step.

Next, snug the wires flat in the interior, making sure the lengths of the wires are equal on the outside of the wing. Then carefully place a piece of tape over the wires to include the holes. Carefully work out the trapped air and press the tape securely to the tippet and paper. Be sure not to score the paper with an impression of the tippet.



That's it! Repeat for the other side. For the center double wires, run the tippet parallel from end to end. I've added an outline to show where the tape is located.



This completes the rigging for the top wing. Assemble the wing. This is a bit harder that normal as you must be careful not to scrape or rub the tippet over the wing surface (the tippet color will rub off and ruin the wing) or kink the tippet. As you can see, it's a bit of a rat's nest.



The lower wing is much easier, as there is only one hole per side to worry about. You need two wires coming out of one hole - how do you do that?
Push both ends of one strand of tippet through the hole from the inside and keep a loop inside to secure with tape. How easy is that!



Okay, the lower wing is rigged, ready for final assembly.

That's the basic idea with building the rigging into the wing from the get-go. The tape is a fool-proof, quick, and easy way to attach the tippet to the paper, and it reinforces the holes from tearing later when you snug up the rigging. The rigging simply protrudes from the wing as in a real aircraft - no glue blobs or mess. You can appreciate how you must plan the rigging beforehand to insure the wires are long enough to do the job.

Next we'll rig the empennage.

[malachite]

I look forward to seeing the next installment. Keep up the good work.

[DrLaser]

Wings - one more thing

Be sure to form the airfoil shape after the holes are punched and before any tippet is installed to prevent any embossing of the tippet shape in the cardstock by the airfoil-shaping tool.

Empennage

The rigging for the "tail feathers" begins and ends in the fuselage tail cone, using one piece of tippet. The tippet emerges from one hole in a similar way as the lower wing, using tape over the loop of tippet. You will notice I cut off all tabs and use butt joints backed by internal splices when I build a fuselage (the only way to go in my book). If in a model the tail part is rather long, just tape off the loop where you can get to it.



Next build the remaining tail parts, poking holes in the rudder and stab where the rigging will attach before you assemble anything.



The built up tail assembly is ready for rigging.



There are two strands for the rigging. One for the front loop around the feathers, and one for the rear loop around. Just feed it through the holes in the rudder and the stab and back into the single hole in the fuselage tail, using the tweezers to grab and pull the tippet out of the fuselage.



At this point the only thing left to do is snug the tippet and tape it secure. This can be done many ways, but I use a Third Hand to hold the part so I can snug and secure. You could also just use a small clothes pin to grab the tippet against the end of the fuselage and snug it that way (probably easier).



The procedure is to use the tweezers to grab the tippet and gently tug at it around the loop, moving from joint to joint taking up the slack. You just want to take up the slack, not put much tension on anything - it's just paper. Do not pull from the fuselage to take up the slack, but work it from each joint in turn. With the small amount of tension held by my clothes pin weights, I use the tweezers to position a piece of tape to secure each wire in turn. Then cut off the excess tippet. You now see why the long lengths are necessary - you need something to grab for the snugging up.



The empennage is done, just add the tail wheel. You may want to add a drop of glue at each joint to "fix" everything. I didn't in my model - just one more opportunity to mess it up.

Next - assembly of the fuselage, the wings to the fuselage, and more rigging.

[rockpaperscissor]

I am so happy to see this tutorial. I have a LOT of unprinted, unbuilt emodels of WWI birds (purchased and freebies) that I have never dared to tackle because of the dreaded rigging. You make it look easier than I'm sure it is, John, but I think I'll print one out and start it using your tutorial as a guide. I'll be watching with interest as your model progresses. Thanks for sharing your technique.

[Don Boose]

Excellent. This is a really valuable tutorial.

Don

[Paperwarrior]

Great stuff!
This is really a big help!

[DrLaser]

Fuselage-Wing Assembly

Now simply assemble the main fuselage to the tail assembly then add the lower wing. Now is a good time to finish the cockpits and their interiors.

DESIGN FLAW ALERT: The cut-out for the lower wing as drawn on the fuselage is far too small to fit the wing. It must be enlarged considerably to accommodate the actual airfoil cross-section.

When inserting the wing through the fuselage wing slots, extra care must be taken because of the tippet protruding from the lower wing. You do not want to kink the tippet, and you do not want to mar the wing surface with Sharpie rub-off as the tippet and wing pass through the "just-snug" slot. Use a sacrificial piece of thin paper between the wing surface and tippet as you slide the wing through the slot. Also, feed the tippet through the slot first, then the wing, to "manage" the tippet correctly and with minimal wing surface contact time. Tada!



Now is usually the hardest part of building biplanes - attaching the interplane struts. A butt joint is a weak joint and getting everything right when assembling the wings is difficult. But it's easy with a mortise-and-tenon type joint. Build the interplane strut with an extra tenon tab, and cut a slot to fit in the wing (easy with the needle tool to help). Just make it a snug fit.



You can actually assemble the wings without glue to check the fit and glue each joint one at a time. I make a cardstock jig at the correct angle when the struts are angled to get it right. When satisfied, glue on the top wing - just don't get any glue on the tippet (those wild strands do tend to get in the way). Note the cabane struts have not been installed yet. I choose to wait till I clean-up things first.



Wing-Fuselage Flying Wire Rigging

Now for the fun part. I chose to add the rigging hole to the fuselage now, as a fault tolerant measure.



Another tool that I have found useful (invaluable actually) when reaching those hard to reach places and applying pressure is a right-angled needle tool.



With the rigging holes in the fuselage, carefully insert the appropriate flying wire into the fuselage, passing it out through the nose. Insure the wires are not crossed, but parallel to one another. Also install the double inner wing-to-fuselage wires. Things are getting organized now. You can see the floor I added to the interior, and the interior sides as well.



Wing-Fuselage Landing Wire Rigging

All that is left to rig are the wires from the lower wing, but the cabane struts need to be installed.

DESIGN FLAW ALERT: The cabane struts as designed are too short by about 50%. I made a new set from an extra printing of the interplane struts. Cut them to length only after you test fit them.

The cabane struts are secured to the top wing by the same tab-slot system used on the interplane struts (cut the slots before you assemble the top wing). You really need that tab because the flying wires are going to pass through a hole in these struts right at the wing surface, so the structure of that tab is essential. Punch the holes in the struts right at the wing surface level, and glue them to the wing (at least). I actually glued them to the fuselage after I rigged them - no reason.



Once the cabane struts are rigged and secure, I added rigging holes just inside of each strut and passed the landing wire rigging into the holes in a crossed pattern and out the fuselage nose. All rigging wires should now be exiting out the fuselage nose. Now we have an very organized mess of wires - whew!



Next step - Finish the rigging - tension and secure that rats nest.

[DrLaser]

Fuselage-Wing Assembly - one more thing

When a biplane has a double flying wire (from top wing to lower fuselage) and a single landing wire (from lower wing to upper wing), many times the wires intermesh by design. This varies from aircraft to aircraft, and it is a test of precision when building a model. Just keep this in mind when you string the rigging. Note if the rigging presses on other rigging when tensioned. Adjust how it is threaded if there is a problem. In the Stearman, the rear landing wire passes between the pair of rear flying wires, as shown here. Looks like I got it right.



Finish the Rigging

Now the fuselage has 16 individual strands of tippet coming out of the nose. The next step is to tension and secure all those strands. With such a mass of wires, you have to approach it with a plan. There are four wires per side entering the upper fuselage, and four wires per side entering the lower fuselage. I'm going to tape the upper wires and glue the lower wires. But I need a jig to hold and immobilize the model, and to orient the model in various ways, while I secure the rigging. So it is time to get out the Legos and make that jig (Fig.52, Fig.53). You need to hold the model somehow, and Legos work for me.



Okay, organize the wire mess by separating out the four wires you want to first work, and get the others out of the way (Fig.54, Fig.55).



You will notice I have the four wires individually separated, weighted with clothes pins, and neatly against the upper fuselage side, giving plenty of room for taping. Gently apply some tension by tugging on the clothespins, just enough to straighten and "crisp up" the rigging, not distort the model. Use tweezers to apply one piece of tape per pair of wires (Fig.56).



Once the tape is secured by rubbing out the air, you can cut off the excess tippet. Repeat for the other side (Fig.57).



I believe I could get away with taping the remaining wires as well, but I will glue them to demonstrate that technique. First you need to build a "Glue Strut" from doubled cardstock that fits the lower fuselage and securely glue it in place (Fig.58, Fig.59). It will end up taking all the tension of the remaining wires.



The Glue Strut can look like almost anything - straight edged, multiple notches for each wire, whatever. It is best to separate each wire so it has room to be glued and tension them with clothes pins (Fig.60, Fig.61).



Again, tension each wire in turn, getting them looking straight with no model distortion, then apply a generous dollop of contact cement over the entire strut region (Fig.62). Let it dry several hours if not overnight. THERE IS NO ROOM FOR ERROR HERE. When ready, trim excess tippet (Fig.63).



Now all the rigging is done - whew. Here you can see the taped wires (Fig.64) and the glued wires (Fig.65). Again, you can see the interior floor (Fig.63). When the tippet enters the lower fuselage, sometimes you will need to fish it out with a hooked wire or tweezers as it may get trapped in the interior rather than come out the front by itself.



Now all that's left to do is finish the Stearman as a normal cardmodel build - next time.

[Paperwarrior]

Wow! Amazing how clean that looks. Thanks tons!

[DrLaser]

Finishing the Stearman

Now that the rigging is done, we can close out the nose with the engine plate (Fig.66, Fig.67).



Next is to add the landing gear. My technique for making wheels is to make them from a buildup of cardboard, the type used to back pads of paper (Fig.68, Fig.69).



Once the two halves are glued together, use an emery board to sand the wheel into the round shape. Then use a colored pencil to finish the wheel (Fig.70). Then install the landing gear as normal (Fig.71).



Finally build and install the engine. Since the engine is totally exposed, I wanted an engine with a bit more realism than the FG supplied version. It took me a while to figure out a design that I could actually build at 1/72 scale - but it was worth it (Figs.76-79).



Rigging Recap

Just for reference, here are some close-ups of the rigging (Figs.72-75).



The rigging actually works as in the real thing, strengthening up the wing structure.

Conclusion

The Stearman was an fun build and topic for this tutorial. I believe the basic concepts behind my technique have been demonstrated here such that you can try it. You got the basic idea here, and I'm sure you will develop your own approaches as well. It's not all that hard, just take it one step at a time. These same techniques can be used for control cables, more complex rigging in pioneer and WWI aircraft, rigging for monoplanes, and radio antenna wire. Just build it into the model from the beginning, and take the time to plan it out first.