From FDM to Resin

Resin prints are known to impress, but when does it make sense to buy in? Filament based printers and resin printers have very different printing processes and workflow. Sometimes there are even additional expenses, in terms of other consumables beyond the resin. Getting your hands on a resin printer is far more accessible now than it ever was. Here are some details to consider before making the switch from FDM to resin.

“Resin-based 3D printers using stereolithography (SLA) and especially digital light processing (DLP) are getting more common and much more affordable. Prosumer-level options like Formlabs and the Prusa SL1 exist, but more economical printers like the Elegoo Mars, Anycubic Photon, and more can be had for a few hundred bucks. Many printers and resin types can even be ordered directly from Amazon, right at this moment.

FDM printers deposit molten plastic with a hot nozzle, while SLA/DLP printers use an ultraviolet light source to cure liquid UV resin into a solid. Both build a three dimensional object one layer at a time, always building the next layer on the foundation of the previous layer.”

Consider sizing.

“Compared to FDM printers, build platforms for resin may seem revoltingly small. The more economical DLP printers have build platforms that are roughly the size of a cell phone screen. Which, as it so happens, is exactly where their LCDs are coming from (with the addition of a UV backlight to cure the resin). A “peel” process pulls the model off of the build surface after every layer, and the model must withstand this. Each new layer must be on a strong foundation, and the best way to ensure a good foundation is with supports. A model orientation that offers a minimal cross-section (and therefore minimal area per layer) will reduce peel forces.”

Multiple supports are imperative.

“With FDM printing supports are often avoidable, but not so with resin. Supports provide overall structure and strength to the model as it is subjected to forces that FDM prints don’t need to worry about. Rafts and supports are the norm, not the exception.”

Say goodbye to overhang and bridging.

Is this a good or bad thing? That’s up for you to decide.

“Compared to FDM printers, resin printing will seem as though it has virtually no tolerance for overhangs. With FDM, an unsupported overhang may result in a droopy edge or poor surface quality, but with resin printing that unsupported bit is likely to break or float away (or remain stuck to the build surface), contaminating the resin and interfering with the print. A part orientation that makes layer changes as gradual as possible will minimize the steepness of overhangs, and therefore minimize the need for supports.”

These three highlights are just a sample of differences you will meet. Read the full article to discover the rest.

Categories: Design & Process