When I was on my know quest a few years back, I ran into a site that linked this cool program Rod. Too cheap to buy it then (and I'm still cheap). lol

And something by the same developer that might be up your street Lyle.
http://www.pretzangles.com/

also the third of same author looks very interesting

http://www.stevenabbott.co.uk/Knots/knottyer3d.html

it says it's for the mac

Nope - it's for windows. Quote from site: Click here to download v1.19b. Unzip it into a convenient folder and it should run under XP, Vista or Windows-7 (even the 64bit version)

oh sorry i didn't see that

No problem. i make that kind of mistake all the time.

A couple of examples of knots 3D using the random function.

Those are great!
Thanks for the links.

No problem.

Just ran across this Because of malware being found in SourceForge downloads, this link has been removed.
at Sourceforge. Unfortunately, the Windows MSI installer is missing all the required DLLs needed to run, but most of the DLLs were in Inkscape (and a few I had to find online). Works pretty good (but did crash once). Despite requiring a few PNG DLLs, it doesn't appear to export any bitmap format; only XML and 3D PLY format. If interested, I can be coaxed to zip the DLL files and post them here, otherwise, it's just another possible fun toy. I did a screen grab for this one; it does 3D cubes too, but kept it on the 2D flat side. As another side note, I did email the creator with my issues; maybe he will or won't email me back, but hopefully he will.

Now, I'm just having a little fun with my concoction.

Looks fun Lyle but I doubt I could use it if it doesn't export bitmaps. Thanks for sharing though. If you come across anything else, don't hesitate to post.

Got an email from David (creator of this cool tool; why are all to programmers named David? {including the creator of FotoSketcher and of course our own Mr. G'MIC himself; lol}). I should have installed the exe file instead of the MSI which installs all the necessary GTK libraries and such. Anyway, David did say it would be cool idea to export PNG files so maybe a future version will. Still, the PLY file can be ported into Blender for those who do 3D stuff (don't use 3D programs myself, but I do know many here do).

3D - Blender -? NOW I'm interested!

uh oh, another binge coming on?

How did you guess 2-ton?

Thanks Lyle. - I would be interested in those dll files please.
http://www.flypig.co.uk/?style=1&page=celtic
If you render as full page it will let you save image as PNG format.

@ Erisian
a bit OT with knots but if you like 3D you should give a look to Topmod
better if you first look it in action on some youtube video, that explain better than words why i suggest...fun and intuitive.
well intuitive only after you see it in action in a video , but that took few minutes, without looking in action in a good video doesn't look much intuitive and so become much less fun to use