Helical Gear. Base Tangent Length 1

[colbtech]

Hi folks,

I am trying to write a spreadsheet for calculating the Base Tangent Length. (Wk = mn.Cos(αn)[(k-0.5)π+z(inv(at))+2mn x sin(an))
Rather than use a table for k (number of teeth) I want to be able to write it into the spreadsheet.

I am struggling to find a formula for this.

The closest I have come is:
kth =zK (f ,β)+0.5

the only part of which I recognize is the helix angle.

Anyone help?

Colin

 

[gearcutter]

A quick 10 second search on Google ("base tangent length" equations) yields this link, pages 159-160 -

https://books.google.com.au/books?i...age&q="base tangent length" equations&f=false

 

[tbuelna]

Don't know what your time is worth, or maybe you're doing this just to learn more about gear inspection, but for $99(US) you can download a spreadsheet that performs the calculations you require.

 

[Occupant]

I think, you overlooked a few things. -->

 

[colbtech]

Many thanks all. The last file did the trick, although I had located the same formula on a Chinese website. Just didn't translate it!!