openscad/threadlib
1
0
Fork 0
mirror of https://github.com/adrianschlatter/threadlib.git synced 2025-01-16 20:58:26 +01:00
Code Issues Projects Releases Wiki Activity

Add tech-docs for metric thread (#23)

Browse Source 
Describes the choices made when deriving threadlib specs from the metric
thread norms.

closes #7
This commit is contained in:
Adrian Schlatter 2019-05-26 19:00:07 +02:00 committed by GitHub
parent 8865c654ce
commit 7e30d8e824
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 15 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
docs/MetricThread.md Normal file
View File

@ -0,0 +1,15 @@
# Metric Thread
![Metric thread specs](http://mdmetric.com/tech/din13pix.jpg)
metric_thread.csv provides the numbers given in the norm (no thinking done there, just copying). metric_thread.awk - as usual - calculates the threadlib specs.
- Designator: use the simplified variant
- Pitch diameters: Choose the center of the tolerance range
- Support diameters: Center of tol. range
- Valley diameter: Border of tol. range so that overlap with support is assured
- Crest diameters: Center of tol. range
## Specialties
For some internal threads, we get a valley diameter that is on the corner or even outside the fundamental triangle. This would lead to one turn of the thread overlapping with the next turn which we need to avoid. Therefore, we have a built-in check to limit the valley diameter to a safe range.