Who needs a 3D printer when you have a hot glue gun? A new Hackaday project from Donald Papp shows us how to use molten PLA filament to glue 3D printed objects together.
When 3D printing ambitiously sized projects, hot glue guns come in handy as a tool to join two separate things together. But what if you could bind these objects with the very same PLA filament that you used to 3D print in the first place?
A recent post on Hackaday by Donald Papp proves that this is possible. The author successfully transforms a hot glue gun into what can be described as a larger and more powerful 3D printing pen.
As to how he decided to use PLA instead of actual glue, Papp wanted a more efficient way to piece together a hollow model. He explains:
“It’s a workable process, but I felt that hot glue just wasn’t the right thing to use in this case. Hot glue can be slow to cool completely, and will always have a bit of flexibility to it. I wanted to work fast, and I wanted the joints to be hard and stiff. What I really wanted was melted PLA instead of glue, but I had no way to do it.”
However, he also realized that a hot glue gun offered what he needed, including good ergonomics, tip visibility, tactile feedback, and simple mechanical operation. So he wanted to see if he could use one to melt PLA instead of glue.
To make this idea work, Papp 3D printed his own glue sticks out of PLA, designing them to fit and extrude out of the hot glue gun. After testing the feasibility of his idea, the maker goes on to test the bonds of the PLA-based “glue”, and the results are quite surprising.
Of course, the PLA hot glue gun works best on the inner surface of a 3D model, especially if you’re trying to keep the outer aesthetic as clean as possible.
For today’s weekend project, you can transform you hot glue gun to work with special PLA “glue sticks”, and furthermore, use it to join your 3D prints together or just have some fun.
PLA Hot Glue Gun: What Do You Need?
You don’t need much to take on this weekend project. Here’s the (short) list of materials you need to create your own PLA hot glue gun:
PLA Hot Glue Gun: Putting it All Together
While the concept seems simple on the surface, Papp’s project took a fair amount of trial and error to make work. As first, he tried to stuff a bundle of PLA scraps into a cheap desktop hot glue gun, but found he needed the gun to reach a higher temperature to properly extrude the plastic material.
The maker also realized that, in order to feed through the hot glue gun properly, the PLA need to have a special cylindric shape. Basically, the PLA had to be the exact same shape and size as the hot glue stick.
To solve these issues, Papp purchased a high-temperature glue gun capable of reaching 208°C, and then designed a glue stick model to 3D print.
“To feed my new glue gun I needed a cylinder 11 mm in diameter and at least 5 in long. Happily, 3D printers exist for the sole purpose of turning 1.75 mm filament into other shapes and sizes,” he writes.
However, after discovering a problem with the feed mechanism, he had to redesign the PLA glue stick with notches, allowing the hot glue gun to successfully latch onto the material and push it through the nozzle.
After his idea came to fruition, Papp tested how well the melted PLA “bonded” his 3D printed models together. He found the “glue” to be surprisingly strong, and while the pieces weren’t welded together, they did pass his “tug test”.
Interested in creating your own PLA hot glue gun? You can learn more about the process on Papp’s expansive Hackaday post.