VMC300 Toolholder question

[magicniner]

Knowing a change in diameter over a fixed height it's a really easy bit of fag packet sketchery and school trigonometry to calculate the taper angle -
Sine - Opposite/Hypotenuse
Cosine - Adjacent/Hypotenuse
Tangent - Opposite/Adjacent

Do they still teach the basics at school? I meet so many people who don't seem familiar with them I do wonder,

- Nick

[Proteus]

Knowing a change in diameter over a fixed height it's a really easy bit of fag packet sketchery and school trigonometry to calculate the taper angle -
Sine - Opposite/Hypotenuse
Cosine - Adjacent/Hypotenuse
Tangent - Opposite/Adjacent

Do they still teach the basics at school? I meet so many people who don't seem familiar with them I do wonder,

- Nick

This is basic Math Nick, but the Challenge is to measure 100% correct top diameter on the taper and correct distance in between(the taper top i slightly rounded).
Tryed to improve my measurements and got lower dia at 31,61, top dia at 20,9 and length at 30. This gives a Cone angle α = 20.24° = 20°14' , taper 35.7%.
This is definately no standard taper in my opinion...

[magicniner]

This is basic Math Nick, but the Challenge is to measure 100% correct top diameter on the taper and correct distance in between(the taper top i slightly rounded).
Tryed to improve my measurements and got lower dia at 31,61, top dia at 20,9 and length at 30. This gives a Cone angle α = 20.24° = 20°14' , taper 35.7%.
This is definately no standard taper in my opinion...

Your dimensions are almost exactly what I get off the Coventry Easy Change if I try to measure where you have using digital calipers.
Because of the problems measuring the top edge of a frustum with calipers I chose to measure the OD in two places where an easily measured OD is available, at the bottom edge of the taper and the top edge of the groove, with a micrometer then measure the vertical distance between the two with a vernier, that gives me a calculated angle of 10.02 degrees. (Once I'd downloaded a decent calculator with inverse functions to my phone - what's the use of sine without arcsine Mr Samsung!)

If you super-glued your two steel rules together in alignment with the taper you could draw a nice big triangle on a piece of A4 and measure/calculate the angle ;-)
- Nick

[Clive S]

I am not into math but the way I see it is that you could put the tool holder into a known dia. hole in a piece of thin stock to measure the top di. then it would be easy to measure the distance to the bottom. Just my 2p worth.