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wierdscience
10-21-2007, 12:41 PM
The big lathe at work needs a taper reducer for the headstock,it's a 4-1/8" bore.The book says the headstock taper is a #17MT taper.

All the charts I have show MT taperes up to 10 or 11,but no 17.

Is there such a chart,or is the #17 MT just something some drunk Italian lathe maker dream't up?:D

lazlo
10-21-2007, 12:46 PM
They just made it up. Morse tapers only officially go up to MT 10 (according to Machinery's Handbook), and the taper per inch varies for each:

http://www.loganact.com//tips/tapers.htm

Taper Name Large Taper/ Taper/ Angle Small Length
End Foot Inch From End
Center
-----------------------------------------------------------------------
#0 Morse 0.3561 .6246 .0521 1.4908 0.2520 2.00
#1 Morse 0.4750 .5986 .0499 1.4287 0.3690 2.13
#2 Morse 0.7000 .5994 .0500 1.4307 0.5720 2.56
#3 Morse 0.9380 .6024 .0502 1.4377 0.7780 3.19
#4 Morse 1.2310 .6233 .0519 1.4876 1.0200 4.06
#4-1/2 Morse 1.5000 .6240 .0520 1.4894 1.2660 4.50
#5 Morse 1.7480 .6315 .0526 1.5073 1.4750 5.19
#6 Morse 2.4940 .6257 .0521 1.4933 2.1160 7.25
#7 Morse 3.2700 .6240 .0520 1.4894 2.7500 10.00

Rich Carlstedt
10-21-2007, 09:09 PM
The taper is not a Morse as lazlo commented, it is a probably a custom taper
by the manufacturer.
According to Standard Industry practice and machine tool standards,
all tapers larger than a Morse #7 have a .750 of an inch taper per foot.
Morse is around .624 ~~ by size...FYI

At the Mouth (large end, called "A" ) of a #7 , the size is 3.27"

But Larger tapers go by Bore mouth size ( A )and are in hundred increments.
For Example, here are some of the standard sizes.
a 200 taper is 2.00 at A
a 300 taper is 3.00 at A
a 400 taper is 4.00 at A
a 450 taper is 4.50 at A
a 500 taper is 5.00 at A
and so forth
There is no 4.125 that I am aware of

I would turn a plug to fit and use the .75" per foot taper and check it out.
If not, then it ia a propriatary taper form the Lathe builder..
Rich

wierdscience
10-21-2007, 09:19 PM
Thanks guys,that's about what I figured.I was hoping to find some base specs since the lathe's taper attachment is a poor design,but I guess I'll just have to dial in the taper and cut it on that machine.

lazlo
10-21-2007, 11:21 PM
The taper is not a Morse as lazlo commented, it is a probably a custom taper by the manufacturer.

Dang, I really need to get some sleep -- I had to read that sentence three times before I realized what Rich was saying :)


According to Standard Industry practice and machine tool standards,
all tapers larger than a Morse #7 have a .750 of an inch taper per foot.

Wow, that's a cool factoid.