Road salt/ice melter shaker

Two things happened to me recently: I moved out of apartment into a house where I have to shovel and salt my own driveway and walkway; and I bought a 3d printer and learned OpenSCAD.

This was my first OpenSCAD model partly to teach myself OpenSCAD, but also to make a useful winter part to spread road salt or icemaker onto icy surfaces.

At 100% size, the cup is 18cm tall and about 12cm in diameter.  It holds about 1.7L when completely filled.

There are two versions of the cup: with, or without a handle.  The handle is deliberately oversized relative to my medium-sized hand (see picture) because it's designed to be able to get your hand into it comfortably while wearing decent winter gloves (this is for melting ice in sub-zero temperatures, after all).

I've made several versions of the lid with different sized holes for different types of salt/ice melt.  (The size in the filename is the corner-diameter of the hexagon holes).  I personally use the 14mm with commonly available coarse road salt for my driveway, and the 7mm version with a finer specialty ice melt product for walkways (these are the pink and blue versions in the main model photos).  There's also a no-holes lid here as well, which is obviously useless as an salt shaker, but makes a nice little container (I've printed the model just fine at both 50% and 33% scaling).

The threads used here (courtesy of https://github.com/rcolyer/threads-scad) work really well: they have enough tolerance that you can just give the lid a good flick of the wrist and it'll spin itself on most of the way and then it still tightens nicely once fully screwed on, without coming loose.

Just about everything in the model is configurable in the OpenSCAD script (so if you want, say, heptagon sides instead of octagon, or want it more or less twisty, or different height or thicker/thinner walls, different lid hole sizes, or….) you can tweak the settings in the script and generate new STLs to satiate all your ice melting desires.  (You will also need to also download threads.scad from the link above in order to load the model in OpenSCAD).

Edit: In response to a few comments about the handle being too large: I don't actually have monstrous hands, but rather it's by design: when I chose the size I did it by measuring my hand inside a solid pair of winter gloves.  That said, the design should scale easily if you for some reason want to spread road salt on your ice with your bare hands.  :)

Print settings

I recommend using PETG.  PLA might work, but since this is something you are shaking violently in sub-zero temperatures while cursing at the frigid cold air, and might occasionally drop, I worry that PLAs brittleness might lead to a noticeable increase in the amount of cursing involved in the ice melting operation.  PETG, on the old hand, seems to hold up nicely in sub-zero temperatures without getting brittle.

The cup with the handle requires supports under the undersides at both bottom of the handle, and under the horizontal section at the top of the handle.  When I printed these, organic supports in PrusaSlicer wasn't a thing yet so my supports for the top part of the handle built on top of the bottom part of the handle; it worked fine, but I imagine organic supports should make that much nicer (though I have not tried).

Perimeters/infill: I suggest using enough perimeters so that the main body of the cup is just perimeters (no infill): at 100% size that means at least 3 perimeters with a 0.4mm nozzle or 2 with a 0.6mm nozzle.  Infill choice is not that critical; I used 15% gyroid infill, and it seesm to work just fine.

I printed with a 0.6mm nozzle and 0.3mm layer height, and it took around 14h on my Prusa i3.  It should print just fine with a 0.4mm nozzle, too, but will take about twice as long.