taper turning for Newbies

irishwoodsman

irishwoodsman

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This is the formula for calculating a taper:
Large diameter of the taper minus the small Diameter of the taper divided by the length of of the taper will give you the taper per inch.
You will also need to know the included angle of the taper if you ar cutting this taper.
This formula would be Tangent of the included angle divide by 2.:)) mac

 
Yes indeed.

May I add that I've had to match/measure unknown tapers and sometimes it's hard to get a mic reading at the absolute large and small diameters. What to do? Well... A bunch of things.

1) Place it on a granite table with a height gauge and measure at any low point. Move either the height gauge or work piece a precise known distance and measure at a higher point. With this, you now have the coordinates of a triangle and can calculate the angle.

2) Put the piece on a mill table (choose any method you prefer) and put a DI on a fixed part of the mill head. Move the table a precise known distance and just like above, take measurements at high and low points. There's your triangle coordinates again.

Ray

EDIT: I've repaired/reproduced dozens of beat-up boat propeller shafts and almost all of them have tapered ends. This comes-up more often than you might imagine.
 
Ray C said:
Yes indeed.

May I add that I've had to match/measure unknown tapers and sometimes it's hard to get a mic reading at the absolute large and small diameters. What to do? Well... A bunch of things.

1) Place it on a granite table with a height gauge and measure at any low point. Move either the height gauge or work piece a precise known distance and measure at a higher point. With this, you now have the coordinates of a triangle and can calculate the angle.

2) Put the piece on a mill table (choose any method you prefer) and put a DI on a fixed part of the mill head. Move the table a precise known distance and just like above, take measurements at high and low points. There's your triangle coordinates again.

Ray
Click to expand...
ty ray for adding that it took me many days and hrs to figure this stuff out, but then one day it clicked. lol
:))mac
 
Excellent. Consider yourself among those who have the persistence and tenacity to figure things out!

[Oh, you can also mount a DI on your toolpost and move the carriage a known distance to get those coordinates].


irishwoodsman said:
ty ray for adding that it took me many days and hrs to figure this stuff out, but then one day it clicked. lol
:))mac
Click to expand...
 
Ray C said:
Excellent. Consider yourself among those who have the persistence and tenacity to figure things out!

[Oh, you can also mount a DI on your toolpost and move the carriage a known distance to get those coordinates].
Click to expand...
now thats like tramming isnt it like useing a di up against your chuck rotate your compound and when you get your measurment in thousanths for the big end of the taper the small end should fall in to place of the measurment on the small end of taper:))
 
Oh, let's point-out to folks that if you lay the piece flat and take high/low measurements over some distance, you need to divide the calculated angle by 2. If the piece was centered in a lathe chuck for example, you don't need to cut the angle in half. Take a moment to think about the geometry and it will make sense -just a little hard to describe in writing.
 
Ray C said:
Oh, let's point-out to folks that if you lay the piece flat and take high/low measurements over some distance, you need to divide the calculated angle by 2. If the piece was centered in a lathe chuck for example, you don't need to cut the angle in half. Take a moment to think about the geometry and it will make sense -just a little hard to describe in writing.
Click to expand...
thats because its not between centers now.:)) mack
 
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