If you do much practical 3D printing, you eventually need some sort of fastener. You can use a screw to bite into plastic. You can create a clearance hole to accommodate a bolt and a nut or even build in a nut trap. You can also heat-set threaded inserts. Which is the best? [Thomas] does his usual complete examination and testing of the options in a recent video you can watch below.
[Thomas] uses inserts from [CNCKitchen] and some cheap inserts for 3D printing and some for injection molding. There are differences in the configuration of the teeth that bite into the plastic. [Thomas] also experimented with thread adapters that grab a 3D-printed thread.
Heat-set inserts are a great way to embed mechanically-strong, threaded parts into a 3D print. For installation, all that is required is an economical soldering iron; something most of us already have.
The carriage and counterweight use a v-wheel gantry, GT2 belt, and other common hardware.
That’s fine for a handful of occasional inserts, but when a large number need to be inserted reliably and cleanly, something a little more refined is called for. That’s where [virchow]’s threaded insert press design comes in. It adds 3D-printed parts to an aluminum extrusion frame to create a press that smoothly lowers a soldering iron directly up and down, with minimal effort by the user.
The holder for the soldering iron is mounted to a small v-wheel gantry that rides along the vertical extrusion. The gantry features a counterweight to take care of resetting the position of the iron. [Virchow] admits that the design could be considered unnecessarily complicated (hence the “UC” in the name) but on the other hand, there’s nothing like doing a hundred or so inserts to make one appreciate every bit of comfort and stability.
Heat-set inserts aren’t difficult to use, but a little technique goes a long way. Spend a few minutes reading Joshua Vasquez’s guide on the optimal way to use them in 3D-printed parts to make sure yours not only go in straight but end up looking great as well.
If you’re building mechanical assemblies with 3D printed parts, you’ll quickly realize that driving machine screws into thermoplastic isn’t exactly an ideal solution. It can work in a pinch, but you can easily strip the threads if you crank down too hard. The plastic holes can also get worn down from repeated use, which is a problem if you’re working on something that needs to be taken apart and reassembled frequently. In those situations, using brass heat set inserts gives the fasteners something stronger to bite into.
You can install these inserts by hand, but if you plan on doing a lot of them, a dedicated press station like the one [Chris Chimienti] recently put together will save you a lot of aggravation in the long run. In the video after the break he walks viewers through the design and use of the device, which itself relies on a number of 3D printed parts using the very same inserts it’s designed to install.
The spring-loaded arm can slide up and down the extrusion to adjust for height.
To build this tool you’ll need a piece of aluminum extrusion, some smooth rod, a couple springs, and an assortment of fasteners. Nothing that wouldn’t likely be in the parts bin of anyone who’s been tinkering with 3D printers for awhile, though even if you had to buy everything, the Bill of Materials will hardly break the bank. For the base you can use a piece of scrap wood, though [Chris] has opted to make it a storage compartment where he can store the inserts themselves. We really like this approach, but obviously you’ll need to have access to woodworking tools in that case.
Clearly shopping on the top shelf, [Chris] purchased a kit that actually came with a Weller soldering iron and the appropriate tips for the various sized inserts. If you’re like us and just buy the inserts that come in a plastic baggie, you may need to adapt the arm to fit your iron of choice. That said, the idea of having a dedicated iron that you can leave mounted in the press makes a lot of sense to us if you can swing it.
We can make our 3D-printed parts even more capable when we start mixing them with some essential “mechanical vitamins.” By combining prints with screws, nuts, fasteners, and pins, we get a rich ecosystem for mechanism-making with capabilities beyond what we could simply print alone.
Today I’d like to share some tips on one of my favorite functional 3D-printing techniques: adding heat-set inserts. As someone who’s been installing them into plastic parts for years manually, I think many guides overlook some process details crucial to getting consistent results.
Make no mistake; there are a handful of insert guides already out there [1, 2]. (In fact, I encourage you to look there first for a good jump-start.) Over the years though, I’ve added my own finishing move (nothing exotic or difficult) which I call the Plate-Press Technique that gives me a major boost in consistency.
Join me below as I fill in the knowledge gaps (and some literal ones too) to send you back to the lab equipped with a technique that will give you perfectly-seated inserts every time.
FDM 3D prints might be coming home this holiday as seasonal ornaments, but with a few tweaks, they may even stand up to the tests of the real world as functional prototypes. Heat-Set inserts are one such tweak that we can drop into a print, and [Kurt] spares no expense at laying down a guide to get us comfortable with these parts. Here, he’s created a drill press adapter and modified his soldering iron to form an insert jig to start melting these parts into his next project.
Heat-set inserts grant us proper screw threads in any thermoplastic. Simply heat them up, stake them into your part, let cool, and: voila–a screw thread that’s firmly embedded into our part. We can load these inserts with clumsy hand tools, but why fumble and bumble with a hot soldering iron when we can adapt our drill press to do most of the tricky fixturing for us? That’s exactly what [Kurt] did here. With a 3D-printed adaptor, he’s letting his drill press (turned off!) hold the soldering iron so that he can use the lever to slowly stake the part into the 3D print. Finally, for no additional charge, [Kurt] turned down his soldering tip to mate cleanly into the insert for a cleaner removal.
We’ve seen adapters like this one before, but it’s never too often to get a reminder of the structural bonus that these parts can add to our 3D prints.
