Est. 1998 — 27 years of woodworking knowledge
Re: Really? But.....
ken c
>Alan,
I don't get it either! It *has* been a fun thread though, lots of point and counterpoint.
I guess we each enjoy this hobby in our own way and there's nothing wrong with that but I won't be buying a $200 "precision" marking gauge anytime soon!
Ken
Re: Common misunderstanding
joel
>I think you are talking different measuring systems. We sell sandpaper that is sold by 3M as .3 micron grit. if visible light is the same 0.4u to 0.7u region i'm not sure I could see the paper. and certainly .3 micron sandpaper takes off material. So I am pretty sure we are talking apples and oranges. But my information comes from starrett - they still finish their engineer squares by hand - against a reference. A common 19th century trainee exerciese was scraping 3 cast iron plates together to make 3 very accurate surface plates. Ways of precisoin instruments used to and may still be scraped by hand.
incidently John Harrison who won the Admiretly contest for a clock that would work accuraetly enough for calculating longitude on board a ship was a joiner who between 1730 and 1759, he produced a series of timekeepers, H1, H2 and H3. H1 won the contest and I think it was largely built of wood.
(the clock is in the Greenwich observatory now)
Re: Common misunderstanding
MikeS
>My point from the beginning is that you changed the basis of the discussion. Joel's 0.001 inch is ten times thicker than what Ken was talking about in the first place, I assume in reference to manufacturers' and purchasers' claims of the precision of their tools.
Your own earlier comments were in regard to 0.005 inch precision, about the thickness of two sheets of paper. Yes, I agree that you could see light coming through that. That is 50 times the thickness of Ken's standard.
I was simply saying that standards of 0.0001 inch accuracy did not exist at the time. That was the main reason that clocks required so much weight to operate. My guess is that rebound of the wood surface after tooling pressure is greater than that. None of this prevented John Townsend from producing some very impressive pieces of furniture.
Good news!
Bob Hackett
>That D you ordered finally came in.
I took the liberty of installing it in your name.;^)
MB
Re: Common misunderstanding
kees
>Haven't chequed my new LV/LAjack yet, but it's now the only plane I use. Glad we don't have inches here in Europe ;-)
kees
An Observation
DaveK
>Someone once asked what you would in Eternity. Between this thread,sharpening,benchbuilding,etc it is completely obvious
Re: Common misunderstanding
paul womack
>H1 won the contest and I think it was largely built of wood.
I share your admiration for Harrison, but those are not the facts. He *did* make wooden clocks, and they were very good indeed, but his marine chronometers were metal.
BugBear
Now I will have to watch Longitude again.
Don Thompson - Cutler Ridge, Florida
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