Re: [CAD_CAM_EDM_DRO] Helix Angle

Since:
tan(a) = rise / run

then

a = arctan(rise / run)

Rise in this case is 25.4 mm.
Run is pi * 18 mm * 8 tpi ~= 452.389342176 mm

So:

a = arctan( 25.4 / 452.389342176 )

a = arctan( 0.05614632713897634 )

a = 3.213573579952357 degrees

If you sign up at http://www.nookindustries.com, you can download CAD
files of different assemblies they make, such as acme screws, ball
screws, etc.

Regards,
JJ

On Tuesday, Mar 9, 2004, at 18:17 US/Eastern, Terry Owens wrote:

> Hi,
>
> This may at first sight appaer to be off-topic but it isn't. I nned to
> know
> the answer so I can draw it in CAD to make a part for a CNC machine.
>
> If I had a piece of round bar 18mm (0.7087") and cut an 8TPI thread in
> it
> how would I work out the helix angle of the thread?
>
> Regards,
>
> Terry
>
>
>
>
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