Re: [MedievalSawdust] How did the Norse drill holes?
Thank you! I hadn't seen that one.
I've decided to 'borrow' some scrap tool-steel from work and see if I can't hand-grind some small diameter spoon-bits for myself. Using a hand-made bit in a power-drill may not be an optimum solution but it will likely cure my 'do in period' urges sufficiently. I'll have to build myslef a bow drill for later...
Hmmm, It deserves a different topic but now I'm tempted to build a 15th cent tool-box for 'campain travel and repair' to go with my persona. :)
On 11/30/2010 11:40 PM, Vels inn Viggladi wrote:
Yes, I'm replying to myself -
>From the Mastermyr find: http://www.netlabs.net/~osan/Mastermyr/ImageLib.html images 46-51
Auger #51 is 16.6x0.5x0.7cm; spoon length 2.2cm, width 0.7cm (The Mastermyr Find, Arwidsson and Berg, P13)
0.7cm is about 0.275 inches, or just under 9/32nds of an inch. So, 1/32nd more than your standard 1/4" bit.
I mention because the original poster asked about 1/4-3/8in holes.
>Jay Close, a Colonial Williamsburg-trained blacksmith, forged out acenter-bit at a recent demonstration at Fort Vancouver (Hudson's Bay Co recreation site (ca. 1840) in Vancouver, WA, USA). He just used hammer and anvil - and some files to sharpen the pike, finish shaping and sharpen the nicker, and sharpen the router. Jay's reproduction had a plain, pointed center-pike and not the threaded pike of the picture.>>Actually the picture on the history.org site is the first center-bit I have seen that has a threaded pike.>>-Malcolm
And I think that may be the trick - the year. Prior to 1840 no one had figured out how to accurately and consistently put a screw thread on a pointed cone. Metal screws were available before then, but getting the reducing spiral made consistently hadn't been figured out. It was sometime in 1840's (source: the master woodworker at New Salem, NC) that pointed ended bits were finally possible.
That being said, you can cut a threaded pike with a small file. I doubt for demonstration purposes he'd have spent the additional hours to file the threads, because that wouldn't be exactly entertaining.
That, and with the router, the purpose of the threaded bit is rather superfluous. Threading the pike causes the tool to "pull down" as it is twisted, meaning that very little energy is needed to push the bit through the wood. The curved slope of the router does the same thing as it shaves out the waste. It's not as strong a pull, because some of that pull energy is used to push up the cut out wood, but it does the same task as the threaded pike.