UV Resin Perfects 3D Print, But Not How You Think

At this point, everyone knows that the print quality you'll get from even an entry level UV resin printer far exceeds what's possible for filament-based fused deposition modeling (FDM) machines. But there's a trade-off: for the money, you get way more build volume by going with FDM. So until the logistics of large-format resin printers gets worked out, folks looking to make things like replica prop helmets have no choice but to put considerable time into post-processing their prints to remove the obvious layer lines.

But thanks to this somewhat ironic trick demonstrated by [PropsNstuff], you can actually use UV resin to improve the finish quality of your FDM prints. The idea is to put a layer of resin over the layer lines and other imperfections of the 3D print, cure it with a handheld UV flashlight, and then sand it smooth. Essentially it's like using resin in place of a body filler like Bondo, with the advantage here being that the resin cures in seconds.

The thick resin fills in tough spots quickly.

Now to be clear, this isn't a new idea. Our very own [Donald Papp] investigated the process back in 2018, and [Thomas Sanladerer] covered the idea in a video of his own the following year. But the difference here is that [PropsNstuff] doesn't just coat the whole print with resin, he takes a more methodical approach. Working in small sections, he targets areas that really need the high-build properties offered by this technique.

With the tough spots addressed, he then moves on to coating larger areas with resin. But this time, he mixes leftover resin from his SLA printer with talcum powder to make a mix that can be brushed on without running everywhere. It takes a few thin coats, but with this mix, he's able to build up large swaths of the print without losing any surface detail.

Is it still a hassle? Absolutely. But the final result does look spectacular, so until we figure out how to build the replicators from Star Trek , it looks like we'll have to make up for our technological shortcomings with the application of a little elbow grease.

Thanks to [Zane] for the tip.

#3dprinterhacks #filler #printfinishing #props #smoothingparts #uvresin

Give 3D Printed Plastic a Well-Worn Metal Look

Affordable 3D printers let us turn ideas into physical reality without a big expensive workshop, but with their power came some disadvantages. The nature of FDM printers impart layer lines and nozzle ridges in the parts they produce. They can be minimized with optimized print settings, but never eliminated. [Emily Velasco] loves the power of 3D printing but not how the parts look. So she put in the effort to make 3D-printed plastic look like distressed metal and showed us how she did it. (Video also embedded after the break.)

This video is a follow-up to her Pet Eye project in response to feedback on Twitter. She had mentioned that the salvaged metal box for Pet Eye wasn't quite big enough to hold everything, so she had to extend its internal volume with a 3D print box on the back. It fit in so well that the offhand comment surprised many people who wanted to know more about how it was done. So she designed a demonstration cube covered with mechanical characteristics, and gave us this walkthrough of its transformation.

Similar techniques can be found in other fields like fine scale modeling. But historically those fields did not have to deal with the challenge posed by layer lines and ridges of 3D printed plastic. In any case we love seeing this cross-pollination: just as 3D printed parts are used to customize fine scale models, we can incorporate well-aged metal finishing techniques to 3D printed parts. It's another tool in our box for 3D print finishing alongside tools like heat and even salt.

#3dprinterhacks #3dprinted #howto #postprocessing #printfinishing #printsmoothing #sanding #smoothingparts