Lincoln-Like Mini Logs - Buildable desktop toy

Based on the historical toys. These are a love-letter to the hours upon hours spent making things with “full-size” Lincoln logs, in the houses of many different grandparents / uncles / friends growing up.

Included are model files for everything needed to build your own little mini-cabins or forts.

• Logs - Full and half-logs, some in batches. Lengths are measured in log notches, from 1n to 6n.
• Slats - Roof slats and anchor slats of various lengths, e.g. a 3n slat is the same length as a 3n log.
• Other - Roof gables, chimneys, windows, doors, and build plates. Print things as-noted, which usually just means “lying down flat”.
  • The roof gables / chimneys come in 2 flavors: “classic” style, which imitates the original wooden parts (and require the use of “Anchor” slats on the ends); and “Playskool (PSK)” style which imitates the hollow plastic parts from later sets that I remember.
  • Doors and windows are printed in two separate parts. Just press and snap the inner window / door into the appropriate size frame.

The examples were made with wood-fiber PLA for the logs, and various colors of PETG for the rest. Made with a Prusa MK4S, 0.4mm nozzle, 0.15mm layer height. Absolutely NOT recommended for small children of choking-hazard age, but a great gift for any fully-grown-adult child in your life.

Printing

No (additional) supports are needed; the logs have their supports built-in and everything else should print flat without much fuss.

To ensure the notches are as good as they can be, the logs include built-in supports for all of the notched undersides. They keep everything nice and dimensionally accurate, and give you some great bed adhesion. I highly recommend using the “marker trick” on your log supports: add a “Pause” code at the start of your first bridging layer, then during the print run a large-tip permanent marker down the center of the built-in supports (the tip will ride nicely down the center, between the two lines). The individual logs will snap free like magic once the print is done, and your cleanup is incredibly fast. It makes a huge difference if you're printing several hundred tiny logs.

For easy printing in large batches, the supports all protrude slightly and many parts also include little tabs on the ends. Just line up your logs so the notch supports line up, and use your slicer to add in a “Box” primitive to bring together everything on the ends. The supports and tabs work together to give you a much easier first layer, and help so that even if something breaks free of the build plate it will stay more-or-less in place to minimize the chances of ruining the rest of the batch.

Assembly

Build plates were never really a “thing” with the traditional toys, but I designed some anyway. They're meant to provide a little bit of structure to your layouts before the first layers are “locked in”, but also give you a way to (carefully!) pick up your tiny cabin and move it elsewhere if the need arises. If your build plate warps too much after printing, try reducing the number of horizontal “bottom” layers (or disable the bottom surface layers entirely).

Press down gently on the joints as you build, and your logs will naturally shift themselves into alignment.

Design

All the design was done from scratch using parametric vars in FreeCAD, making guesses on the dimensions based on my own memories, studying photos of old sets from eBay, and looking through the directions I could find online.

Logs are based on a filleted-hexagon shape, instead of a “flatted” circle. Pretty much every other design I've seen is made to print sideways, which means you end up with logs which are flat on the sides… I wanted a log that I could print in the “correct” orientation, to end up with rounded logs on the outer edges. Not to mention that hexagons are, in fact, the best-agons. And unlike the traditional toys, the notches are not only angled but slightly shallower: this lets you build with all the weight resting on the notches instead of the flat log surfaces, leaving very tiny gaps between each log and the one on top of it. The resulting constructions are MUCH less wobbly than those made with traditional Lincoln logs. (Fun fact: real logs on full-size cabins are notched in the same way, for the exact same reason.)

Everything is roughly 36% scale to the original toys. This wasn't a really conscious decision, but more experimenting and tweaking with various sizes until I found one that was sufficiently tiny but still large enough to print and easy enough to build things with my fingers. A 7.5mm log diameter gave me a nice easy 15mm base “unit” to work with, and printing anything smaller would have required tweezers and / or possibly a smaller print nozzle.

Update 09/07/2025: Added doors and windows