thread lisp
Still no attachment, if you tried again with Post 20. If you were Replying via a smart phone, I understand some have trouble getting things to attach successfully from those, in which case you may need to get to a "real" computer and try again.
Kent Cooper, AIA 
@Anonymous wrote:
Can you just write files for acme threads, square threads and unified threads? I'm not familiar with Lisp in order to do it on my own.
Give some more direction about "unified" threads [see Post 8], or alternatively, confirm that there really are not different varieties [this is all outside my experience]. The attached [minimally tested] does Acme and Square, with the same limitations as described in Post 13.
When you said "I loaded the app" in Post 16, I assumed you meant you put the code in Post 13 into a file and loaded that, but did you really mean the routine in the link in Post 3? If 13, I'd still be interested to see your file to try to determine why it didn't work. If 3, I still haven't tried that, but it's for 3D threads, anyway, so there's no point in analyzing it for your purposes.
Kent Cooper, AIA
@Kent1Cooper wrote:
Give some more direction about "unified" threads ....
Further complication about that -- the Wikipedia entry shows that the "peak" and "valley" conditions are different for the internal vs. the external threads. That's not a feature of the 10 choices in my first link in Post 8, but their diagrams don't say enough about the relationships between pitch and depth and so on. Do you need the precision of that distinction between external and internal thread profiles? Or if you need only one compromise version, what would the compromise conditions be compared to the Wikipedia diagram?
Kent Cooper, AIA
@Anonymous wrote:
You're mistaking me for someone else. ....
[ @john.uhden's post mentioning "your cousin Sheldon" was actually in Reply to me, and I assume about the fictional character "Sheldon Cooper" on the TV show The Big Bang Theory. Not that I knew anything about that, never having watched it -- I was just curious enough to do a web search, and found "him."]
Kent Cooper, AIA
@Kent1Cooper wrote:
.... The attached [minimally tested] does Acme and Square, with the same limitations as described in Post 13.
....
Or, since they had so much in common, this one defines one working routine, and two commands that call it with different argument values. If "unified" thread profiles can be symmetrical between internal and external threads [see earlier questions about them], then a third command could be added to this with all of three code lines as for the other two, with a different argument value.
Kent Cooper, AIA
@Anonymous wrote:
Yes, unified" thread profiles can be symmetrical between internal and external threads. So far the program works fine.
So look at the image in the Wikipedia article. It has "sharper" points on the outside of the external threads than on the inside of the internal ones, and it has rounded "valleys" but flat-topped "peaks" on both, and the widths of the peaks and distances from them to the pitch line differs between the two. If that can be simplified to being balanced around the pitch line, and flat on both peaks and valleys with the same width, with the overall height/depth being half the pitch as in the other styles, and if the only meaningful difference from "Acme" threads is the 60-degree angle instead of 29, then it's a simple addition of another command definition to the code, with a different numerical argument [and adjustment of the Prompt when loaded]:
(defun C:UST () ; = Unified Screw Threads [2D profile only]
(screwthread 0.1443376)
)
(prompt "\nScrew Thread profiles: AST to draw Acme, SST for Square, UST for Unified.")
Kent Cooper, AIA