A Functional Resin 3D Printer Smaller Than Your Thumb

Aug 31, 2023

Resin 3D printing, particularly the MSLA (masked stereolithography) process, has exploded in popularity over the last few years. Resin printing is known for producing very detailed and smooth models with virtually invisible layer lines, but was too expensive for most hobbyists until relatively recently. Now, inexpensive LCD panels and UV LED light arrays have driven the costs down a lot, with small models sometimes dipping below $100. But what if you wanted to go really small? That's what YouTuber My N Mi did with this functional resin 3D printer smaller than your thumb.

That is not hyperbole. This entire 3D printer is around the same width and depth as an adult man's thumb, and is actually quite a bit shorter. The overall size is 18x31x41mm. And unless My N Mi is pulling some really clever camera tricks, then it is also completely functional and capable of printing resin parts. The build volume is just 11x11x17mm, which means that it is limited to printing ridiculously tiny parts. But that just adds to the mystique.

Unfortunately, we know very little about the technical details. My N Mi says that the XY accuracy (presumably the pixel size) is 0.135mm and that the Z resolution (layer thickness) is 0.005-0.03mm. The latter is normal for an MSLA printer, but the XY resolution is poor — though still good enough for some decent prints. The frame is some kind of wood, but we don't know any other details about the parts used. The Z axis has dual rods and some kind of screw, which is about all we can see.

We can, however, make some inferences. There is probably a small LCD panel with the backing removed to make it transparent. The light probably comes from a single UV LED. And it probably uses a small microcontroller for control. Hopefully My N Mi will post some more details in the future, because we'd love to know what is going on inside of this miniature 3D printer.