3D Printing with Hot Glue Has More Benefits Than You Think

We all use hot glue as an analogy when trying to describe to regular people how FDM 3D printer extrusion works. So, it is only natural that crafty makers have tried to use hot glue as a 3D printing material. People were doing a lot of experiments with it in the early days of hobbyist 3D printing, but it was mostly written off as other materials proved to be far more practical in most situations. But Jón Schone of Proper Printing thinks we need to take another look at hot glue and so he built an extruder to 3D-print it.

Specifically, Schone is interested in printing with material in the hot glue stick form factor and that is an important distinction if you want to understand his motivation. It is relatively simple to print with hot glue in filament form on a spool, but Schone’s project is less about that hot glue material (usually a mix of EVA, styrene, and other polymers) and more about the stick form.

Why? Well, consider what materials might be easier to print if they came in thick sticks, as opposed to thin filament wound up on a spool. Very soft materials, which tend to jam up traditional extruders, would definitely feed more reliably. That stick form would also suit brittle materials that simply can’t be wound onto a spool at all. You might also be surprised by the vast selection of hot glue materials on the market, which extend far beyond the standard general-purpose stuff that we’re all used to.

To make that happen, Schone engineered a special extruder based on a previous design of his. That uses belts instead of the usual gears to get a good grip on the material across a large surface area. It receives hot glue sticks from a magazine-fed chute thing. That drops the sticks down into a funnel-like apparatus on the top of the extruder.

Schone originally tried to use the heating element from a hot glue gun as a kind of hot end, but ran into issues with heat creep and leaking. His solution was a bit comical, but it worked: he attached most of the hot glue gun (sans trigger-actuated grabber/pusher) to the bottom of his extruder.

That worked surprisingly well, though it lacks temperature control. Schone was able to print the hot glue sticks with pretty respectable quality. In the future, he wants to fabricate a specialized hot end for this extruder and that would help him print with just about any material that could be made in stick form.