Origin of Morse Tapers series

JW² · 2008-11-26T01:28:19+00:00

Please forgive me if this has been bashed out before, but I've beenthinking again (Oh NO! they cried).For years I've wondered about the series of angles of the MT tapers. Ithought the wierd spread of angles might have derived from some esotericmathematical formula beyond my ken.Acting on the clue that they were originally based on a taper of 5/8"per foot (19.2 : 1) and with the help of Excel and dredging up somerusty trig functions, this results in taper angle of 1° 29' 26.630"Since the MTs all hover round this figure, was it decided by the Wise Men (& Ladies?) that because of its, by then, widespread adoption, to stay with the errors and eventually carry them forward for the ISOstandards? Pehaps only the improvements in measuring instruments andmachining processes since Steve Morse nutted it all out in the mid 1800s only later allowed the small but significant errors to be observed in the standard prototypes?BTW, my calculated angle rounded off is the given taper for MT0, whichleads me to wonder whether MT0 was one of the original series, or (fromthe "0" designation) was it added with the grteater accuracy then available?Or is there a "proper" reason for the series?In the meantime, I'll continue to machine my MTs by setting up against known store-bought tapers.JW²

Nov 26, 2008 25 Replies

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Andrew Mawson 17 years ago

"squaw on

Is that the one with bells on?

AWEM

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Peter Neill 17 years ago

More likely Belles in this context

Peter

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ravensworth2674 17 years ago

Peter

Missed a bed? ( Sacre Coeur!)

Reims of them!!!!

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Peter Neill 17 years ago

Especially around Laon...

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Austin Shackles 17 years ago

On or around Wed, 26 Nov 2008 10:45:31 -0000, "Dragon" enlightened us thusly:

I've got some 7-figure ones somewhere.

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ravensworth2674 17 years ago

d text -

Peter,

Sounds vaguely Italian Funiculee- funicular.

( St Quentin for me-- but who is the guy with the cow's pat on his head?)

Norm

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