Hot glue is a cheap and easy way to fixture pieces of material that can’t be fixtured with double-sided tape. For example, machining wax sometimes has a really rough surface to which tape might not stick very well. Another example would be something that isn’t flat, like a sphere. By filling the gap between the edges of the material and the bed with hot glue, you can reasonably securely attach the material to the bed. The downside of hot glue is that it’s messy and not as strong as other fixturing methods.
How do I use hot glue?
- Make sure you’re using a high-temperature glue gun.
- Make sure your machining bed is free of dust, swarf, glue, or anything else that might prevent the glue from sticking or the material from lying flat.
- Place your material on the bed and align it with the bottom left corner of the bed or the bottom left corner of the alignment bracket, if you’re using it.
- Run a bead of hot glue around the exposed edges of the material.
Don’t put hot glue between the material and the bed because it will increase the height of the material and cause your tools to cut too deep. The material also won’t be flat on the bed, which will cause uneven cutting depths.
Don’t let hot glue drip anywhere on the Othermill. For example, if glue drips onto the metal ways that the carriages move on, the carriages can bind up and push the ways out of the machine.
Don’t use hot glue without the spoilboard installed because glue could drip into the T-slots and render them unusable.
Machining wax fixtured with hot glue and the alignment bracket.
When and with what kinds of material would I use hot glue?
Since hot glue doesn’t provide as much fixturing strength as Nitto tape or bolts, it should be reserved for pieces of material that can’t be fixtured with tape, such as those with rough or rounded bottoms. Otherwise, it works with pretty much any type of material: metal, wood, wax, plastic, etc.
When would I not want to use hot glue?
If, like brass or aluminum, your material requires high cutting forces, hot glue isn’t the best option because it’s not as strong as most other fixturing methods. There’s a chance your material could come loose from the bed during milling. Also, avoid using hot glue with ABS, as the hot glue may melt your material.
How hard is it to use hot glue?
Easy, especially if you use a small glue gun that has good maneuverability inside the Othermill. The only other time it’s difficult is when you want to manufacture the same thing over and over. In that case, you’ll probably want to create a custom fixture or use some kind of clamps with the T-slot bed.
Where can I get hot glue?
You can buy hot glue and hot glue guns at your local craft supply store, some office supply stores, and online retailers.