## Parametric knurled knob with captured nut for 3D printing

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drmacro
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Joined: Sun Mar 02, 2014 4:35 pm

### Parametric knurled knob with captured nut for 3D printing

An example of some techniques using spreadsheet data and spreadsheet functions and expressions.

This file demonstrates one approach to making a parametric knob with captured nut and knurled circumference, typically for 3D printing.

Initially, I set out to make an example for someone who had done a similar thing with multiple datum planes and claimed he couldn't get it to work with attachment offsets on the sketches.

So, things exemplified:
- Use of expressions of the form "condition? resultTrue : resultFalse" in the spreadsheet to get conditional values
- Use of expressions of the form "condition? resultTrue : resultFalse" to limit recomputes when the knurl count gets large
Thus the basic dimensions can be changed without waiting for long recomputes, then the control cell can be changed to produce the final knob.
- Use of miscellaneous built-in spreadsheet functions (floor(), round(), pi, tan())
Spreadsheet cells involved: Knurl count, Circumference, Chord Length, Knurl count calc, Knurl count adj
- Green cells are to be set by user, red cells are calculated (i.e. not to be changed by user)
knurlnut.png (297.66 KiB) Viewed 271 times
https://github.com/macdroid53/MyShares/ ... anup.FCStd
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