Depending who you ask, 3D pens are silly toys or handy tools. Those who use them as tools find them handy to fill gaps in printed assemblies or to use them as a PLA or PETG-based hot glue gun for their prints. [half-baked-research] on YouTube is in the second category, but knows that welding is better than gluing — so he built himself a 3D pen designed for plastic welding.
You can weld with a regular 3D pen, and [half-baked] demonstrates that in the video. But thanks to the low-conductivity tips on commercial pens, it’s a slow, fiddly business. By using a normal 3D printer hot-end, with its conductive brass nozzle, [half-baked] is able to get a lot more heat where it’s needed. That means the plastic on either side of the weld melts for a good bond with the stuff coming out the nozzle. He’s also able to push plastic much faster with the modified extruder he’s squeezed into the hot-glue-gun looking contraption. Those two things together conspire to make the whole process go much faster than with a commercial 3D pen. He calls his build a 3D pen, but given the form factor it might be more accurate to call it a ‘plastic extrusion gun’.
Starting at around 13:38 in the video, he performs some strength tests, something we wish more YouTubers would do. He’s able to demonstrate a stronger bond with his welding pen than the normal 3D pen, and a much, much stronger join than the usual superglue. A traditional plastic weld with hot air is even stronger, but [half-baked] points out elsewhere in the video that on thin-walled prints (as opposed to the solid test articles) hot air welding can be a very dicey business. Pen-welding offers much greater control, so is an interesting technique to keep in mind.
Alas, [half-baked-research] apparently still considers this idea too half-baked to release the design. If you don’t have time to wait or reinvent this particular wheel, we featured a much simpler implementation of a similar idea years ago, using PLA in a hot glue gun. If that won’t work for you — maybe you aren’t a fan of PLA — perhaps you might try friction welding with filament.
The HandHeld HotEnd PEN. I think it’s a great idea to put these out. I was using hot air welding on special special purpose plastic pipe back in the 90’s. You have basically made it into a Plastic Mig Welder. I realize a standard pen is but better heat and speed control. Is key. Again great design. This does fuse the materials together better. Instead of just joining them. The glue depending on type is a chemical fusion. Like a PVC glue or ABS glue rather than super
Yes I would love to have one of these welders
I see a Kickstarter on your future
i just use the printer itself. M104 S250\nG0 Z100 F1000\nG0 E100 F100\n, you get a minute of ooze to rub your part around on the nozzle. Some limitations that haven’t mattered to me yet :)
I remember having a building set that spun plastic tips at high speed to weld plastic pieces together
That’s the friction welding they mention at the very end of the article. There was one marketed as a toy many years ago.
Very much impressed with your video, haven’t joined plastic that way in about 15 years. I used a soldering iron and rods of plastic I cut from a like material, my method was more like brazing and proved to be relatively strong. It did not look as nice as yours. You might have inspired me to go out and break something just to try your Technique. Thank you
Must weld with your creation there is so much potential for repair in a mechanic and I can tell you that that the uses are infinite I could repair bumpers or brackets or anything since modern cars are all plastic bits geniusGENIUS