The One Promise 3D Printing Did Fulfill
3D printing. So much potential. “Consumer 3D printing” used to be the “blockchain” search term of the early 2010’s. An ethereal, wonder machine that printed toys for our kids and helped us fix that door knob with the push of a button threw investors and consumers alike into the pool of promises.
Soon, printers at homes gathered dust, and dozens of startups closed their doors. Chemicals, fumes, smells, post-processing, and don’t get me started on the resins. The technologies that enable both FDM and SLA 3D printing have a lot of inherent elements that still place them far from the same kind of relative convenience a paper printer provides.
The Silver Lining For 3D Printers
There is, however, one category of commercial products where 3D printing delivers and excels: the manufacturing of jigs and fixtures. 3D-printed plastic has the structural stability, accuracy, and affordability for creating intricate systems. This allow manufacturers at both small and industrial scales to streamline assembly processes far more efficiently.
There are so many applications that it is difficult to get started, so I will present a few personal cases and other industry-related applications. This is all meant to inspire you to use this amazing technology to boost your productivity and precision when assembling or inspecting components.
Case study 1: Willo (Sanding Jig)
These components required sanding and finishing. One of our team members had the brilliant idea of somehow fixing them to a drill and effectively turn it into a lathe for sanding.
As you can see in the first image, the inner part of the enclosure is an intricate design with assembly pins and other components getting in the way. With the 3D models available, I could come up with a capricious shape rather quickly that avoided the components, and could be easily assembled. Project successful.
Case study 2: Willo (Alternate Sanding Jig)
This was another sanding jig, but with the premise taken to the extreme: we would stack 10 pieces at a time and sand them. This time, the plastic did not take it. We tried different printing orientations, 100% infill, all to no avail. We had to make aluminum jigs. Project unsuccessful.
Case Study 3: Trophy Cube (Vise for Specific Orientation)
A cube is probably one of the easiest things to fix on a vise or a bench top drill. This isn’t quite the case if you are orienting it at a 45° angle on two axis! How to design a jig for such a specific task?
1. Create a solid version of the shape you want to reorient in the real world and rotate it to the desired orientation
2. “Wrap” it completely with a cubic shape that can be fixed on a vise easily. Make sure to leave at least ¼” space for walls thickness.
3. Subtract the shape you want to fix and cut it in half. Give some allowance for the plastic to expand when printed. I usually give it a 0.01” wiggle room.
Granted, this jig/block was a bit of an overkill. This one piece was going to get CNC treatment and we really did not want any parts flying around. Project successful.
Case Study 4: Wooden product (Quality inspection)
This product features a series of holes and pockets carved on a diagonal surface, and our supplier did not have access to 3D software. This made it very difficult to communicate what we required.
We then 3D printed a section of the product that featured each pocket, diameter, depth, etc., so that the production manager could make sure workers were manufacturing the pieces to specification. Project successful.
Case study 4: Wooden Product (Wedge for Laser Cutting)
The wedge-shaped top of this product posed yet another challenge. When the supplier laser-engraved it, it was clear that they did not place the product horizontally towards the laser and this resulted in a “faded” logo. We designed a wedge with the opposing shape. Every new piece was laid on it, resting flat on the laser cutter. Project successful.
Other 3D Printing Applications
As mentioned, these are just a few applications, but there are many more. Other applications are:
- Size proofing. Negatives where manufactured parts have to fit in, in order to pass quality inspection.
- If a certain component has difficult to reach assembly pins or holes, create a “multi funnel” where you put all screws at once, mount it and start the assembly process.
- Frame for glued components that have to be kept tightened.
- Printing, stamping or placing lettering on a specific point of a surface (even if it is curved) with a jig that works both as a mounting frame and spatial reference.
Technical considerations
- 3D printed parts usually require thicker walls than conventional plastic-injected parts.
- Whenever possible, print the filament path longitudinally though the section where most mechanical force is to be exerted.
- ABS is generally stronger, but PLA works well, too.
- Do not be shy about printing jigs with a 100% infill.
Over to You
While 3D printing may have been over-hyped in its early days, there are still plenty of applications for this technology. Consider these tips and case studies next time you’re facing a problem that 3D printing may be able to solve.
