Friday, January 23, 2015

A half dozen bow drills

Combo #84: Wood bow, modified iron nail drill bit,
and antler socket
I just finished up a set of 216 bow drills for the Nunatsiavut archaeologists to use in school programs in northern Labrador.  Ok, maybe that's a bit of hyperbole, but the six bows, six spindles, and six sockets are all interchangeable, which means there are 216 possible combinations.  Since the kit is going to be out of my hands I'm not going to be able to do my usual maintenance on the sets.  The nephrite can be difficult to sharpen when it gets dull.  A wet lapidary wheel, diamond file, or abrading stone is needed to touch up the nephrite bits when they get dull.  Not every rock is going to work as an abrading stone, but finding one that works is part of the fun.  We went with three nephrite bits and three modified nail bits.  The iron bits are also traditional for the area and will be a little easier to keep sharp using conventional whetstones or metal files. 

The full kit.  The top two bows are antler and the rest are wood.  five of the sockets are designed to be handheld, while the one on the left is a mouthpiece.  The top three drill spindles have nephrite bits and the lower three have modified nail bits.
The nephrite bits.  I made one extra, just in case.

An unmodifed nail (L) and one hammered and ground into a drill bit (R) 
The assembled drill spindles before lashing the bits into place.

This is my first time experimenting with iron drill bits and I wasn't sure if they would want to twist out of the wood spindle, so I added a little 90 degree spur at the proximal end to lock it in the shaft.  I did this on three of the drills and left the fourth one straight.  In retrospect, I don't think its necessary and I believe that the square cross section of the wrought nails will prevent the bits from twisting in the handle.  Although I won't be there to make repairs if that belief is wrong, so its probably better to be safe than sorry.

Assembled.  I went with epoxy and artificial sinew for the binding.  These are going to get heavy use by people of all skill levels and I won't be there to make repairs.  As much as I dislike using artificial bindings, I think it was the right decision for this particular set.

I tested the spindles out with a class of Open Minds students at The Rooms yesterday.  Look how clean they were in the previous photo.  It doesn't take long antique them when you turn them lose on a classroom of grade 5 students.  I'll have to remember that the next time I need to make something look world weary and aged. 

Combination #173: Mouthpiece socket, antler bow, and nephrite spindle
Ready to pack and ship north.
Photo Credits: Tim Rast

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