Parametric leg/cane foot or pen holder

This is a very versatile model-creating OpenSCAD app that gives you the superpower to create almost any round or ngonal-section table leg foot, cane or crutch point, &c., and also can be used to make stylish pen holders. (Size matters!)

How to use

You will need to have OpenSCAD installed in your system. If you haven't, download it here. See, OpenSCAD is a very lightweight and free modelling program; and "free" as in "freedom to drink free beer". The great thing about OpenSCAD is that you don't need to know anything about it to use it: an OpenSCAD file can, such as this one, have the "Customizer" enabled so you only set the values you want for the parameters, hit F6 to render and then export it as STL with F7 or the menu button. There is a huge, growing collection of customizable models and an active and growing community of OpenSCADians that aim to make your life easier; we all know that one of the greatest powers of 3D printing is being able to make objects fully suited to your needs. If you want to learn more about using the customizer and how it all works, check out the bundled "Using OpenSCAD customizer" PDF. 

Tip: you might want to hide the editor (Window→Hide editor) for a better view of the model. Don't close the console; it will display the calculated dimensions of the model, which can be very useful.

In the "Other files" section there is a .JSON file with presets for the displayed models; these can be great as a starting point for your models. Just put that JSON file in the same folder as the .scad file, and they will be available next time you open the .scad file.

All parameters are quite self-describing, and they have an explanation to them. Just bear in mind that the "Main unit" is used for all non-angular measurements (like clearance, body height, wall thickness, &c.) Anything with 90 or more sides will be considered a circle/cylinder/ish, while anything with less than 90 sides will be considered an n-gon. This is important for the hole size; if you want a n-gonal pen holder, for instance, you will need to use the "width" measuring style, that is, 2*apothem of the n-gon, to get the useful width; but in a cylinder, it's better to use the diameter.

Design & print tips

The skewing angle is relative to the vertical (the "pen" or "table leg"), and the "rotation" is useful to set the skewed hole tube in a specific position; check out the triangular pen holder examples provided in the JSON and the pictures.

If you are making a table leg foot, cane point, etc. —use TPU and preferably some degree of padding (pad height parameter). Don't make the squares too small, otherwise you might have problems with print sticking to bed (quite unusual with TPU!). The "breathing hole" is used for solid legs &so, as the tight fitting might cause a pocket of air that makes hard setting the point in place. If the "leg" is hollow (tube-ish), better place a metallic washer inside the point to spread the force and avoid cutting the material.

Also about the skewing angle: don't overdo it in pen holders. Too big an angle for a given base surface will make it unstable (leverage, center of gravity & all those things). Something around 10-15 degrees will usually be OK. Note that you can decrease the angle and increase the floor thickness to have a modular-style, ergonomical multi-row set of holders.

You can also use the negative volume modifiers and print pause GCode in PrusaSlicer (or your slicer of choice) to embed magnets into it. Check out my Sharpiener, a sharpener-shaped pen holder, to see how to do it (that model can create the magnet holes automatically), or if you just want a funny pen holder.

About the model

You may be curious about why, of all names, it's called "Cane point". Well, it happened that by about year 1 or 2 BC (Before Coronavirus), the point of my late uncle-in-law favourite cane broke. My SO spent quite a good couple of afternoons searching for some replacement; and all that was to be found were unusable pieces, either too big or too small and always very flat at the bottom, which makes for bad grip over wet or polished floors. And as it turns out, it's not only racing car tires that need good grip on the surface; the much slower walking-aid-requiring people need it much more. So OpenSCAD and 3D printing came to the rescue; and uncle Ramonet was very happy with his new cane point. That rugged old shepherd was not one to sugarcoat anything, and this simple model became one of those I'm most proud of.