re Roman wood turnings
- --- In email@example.com, "Ron" <williams@...> wrote:
>Bayard, we know they also used bow lathes and may have also used some manner of great or water-power lathe. This due to that the Romans did metal spinning, which really can't be done with the motion of a spring pole lathe. To be exact, (probably among others) they spun the crowns for their Auxiliary and Provincial helmets.
> I was watching Jimmy Clews' video set, "Turn it On" this afternoon. A special feature on Disc 2 was a tour of the museum at the Roman fort at Vindolanda. Items included two turned wooden boxes with snap fit lids, and two needle cases with covers. I know how to turn them with my power lathe and a chuck, but now I have to consider how to make them with my spring-pole lathe. It was fun to see stuff I learned to make a few years ago appear almost unchanged from ones turned in 85 ad.
We also know that face-plate work was not unknown. While not an early English/Anglo tradition, there has been face-plate work found in main-land Europe. There is no reason you can't do faceplate work on the spring-pole, if you provide the power behind the faceplate. I use a faceplate on my treadle lathe.
Recall that the boxes were hard dense wood, I think I recall that one was Boxwood. If I recall (at least) one had traces of Opium in it.
>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.