Drag & Anti-Drag Wires

Before I talk about the wires, I did get more fittings made.  Basically, all the internal fittings are now made.  The only ones remaining are for interplane struts and landing/flying wire attachments.


These are the fittings that attach to the spars and where the drag/anti-drag wires attach.  Made from .100 4130.






These have the same function as the ones above, but are used where the wires start and terminate, i.e first bay and last bay.  Also made from .100 4130












Drag & Anti-drag wires...
The wires are made typical to aircraft of this era - a length of piano wire (spring steel) with a loop at each end and a wire ferrule holding the loop closed.  Some manufacturers would solder the ferrule, others like Lincoln-Page left it un-soldered.  This method of making the brace wires was apparently an area of concern in the aviation industry at the time.  I've come across several in-depth test reports from the late '20's and early 30's testing various methods of making these wire assemblies and trying to improve on them.  It may be due in part to the difficulty in field-making these wires as special fixturing is required.  The later method of using threaded rod with clevis fittings on the ends is certainly a much improved method.

Photo of original.  The free end of the wire is bent around the
ferrule and is really the only thing that keeps the wire from
pulling out of the ferrule.

The wires are not too bad to make with the proper fixturing.  The challenge with these is forming the loop at the ends.  Luckily, I came across a very old aircraft mechanics book that showed how to make the fixture - although it's really not that difficult if you think about it.  The following pictures show the steps.

First - a length of wire is bent into a 180 degree loop

The loop is then put over the middle pin and each leg bent at
about a 45 degree angle

Assembly - a fitting or turnbuckle end goes in the loop, the ferrule is slid over the free end
of the wire and the free end is then bent over the ferrule.

                       

I am making up several of these assemblies to pull test and compare to the originals just to make sure everything looks A-OK prior to making all of them.