Monday, January 10, 2011

Rigging model airplanes and other paths to madness

I have been spending hours working out rigging methods for my WWI aircraft. I have come to the conclusion at there is not only one method appropriate to all models and scales. Smaller scales can benefit from simple methods such as foregoing turnbuckles and wire eye attachment points and drilling through the attachment points in the wings, fuselage, etc and running monofilament through them. Larger scale models, especially the newer variety exemplified by Wingnut Wings kits really demand more detail and faithfulness to the prototype. This will certainly involve the simulation of turnbuckles and attachment hardware instead of mere holes through the wings.

The monofilament loop secured to a wire eye or strut base with a small tube segment gives a very nice approximation of many wire and turnbuckle arrangements, but is time-consuming and difficult to execute. Making the number of required wire eyes and uniform tube segments is arduous and time consuming. An alternative is to slide tube segments over the mono securing them at the top and bottom of the run to suggest turnbuckles. This, and any other method using mono but not the dual loop-eye-tube (LET) method, requires drilling completely through at least one anchor point - wing or fuselage typically. This then requires cleanup where the mono passes through.

One method calls for securing at the attachment point, an eye made from mono reinforced with CA, or with wire, that has had a piece of mono knotted to the eye and glued with CA. The other end of the mono is fed through a hole drilled completely through the anchor point, pulled tight and secured with CA. Again, clean up is required and for German aircraft which normally had turnbuckles at the lower wing and fuselage positions, the cleanup will be at the top wing, a most visible part.

The only methods I am aware of that obviate the need to drill through at an attachment point are those that use a stiff material cut to length and glued into place. Stiff wire, small diameter metal rod, usually brass or stainless steel or similar alloy, or, cheapest of all, stretched sprue can be used. Stretching sprue is difficult to control the diameter of many long segments, but it is useful in the smaller scales and for short runs like control cable segments. It is also amenable to styrene cements unlike non-plastic components.

I am readying to experiment with 0.005" diameter Nitinol and stainless wire on my Wingnut Wings Sopwith Pup kit. Both resist bending, especially the Nitinol. The challenge will be in cutting the precise lengths required, ensuring the location holes are in the correct orientation complementary to the wire's running direction and suggesting turnbuckles, which I initially plan to do with tube segments. However, I am also considering simpler and easier methods such as building up the appropriate shapes with white glue or something similar then painting it.

As Mark Smith pointed out, rigged aircraft in 1/32 scale really cry out for rigging with turnbuckles and turnbuckles typically have a visible eyebolt connected to the rigging wire. The problem then is how to make use of actual stiff wire that connects realistically to the eyebolt. The best eyebolt would be made from a piece of 32 gauge wire twisted around a small drill bit or pin, similar to Bob's Buckles. Making a suitable turnbuckle-eyebolt combination by sliding and glueing a tube segment over the twisted wire eyebolt, leaving just enough of the tag end protruding to attach to the anchor point would be suitable, but how to attach, realistically, a segment of stainless steel or Nitinol wire to it is the issue.

Ideas are welcome.

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