Micro 3D Printing: Make a Micro Chess Set

Very small objects can be created with even an inexpensive extruded filament 3D printer. The Intro Pic shows a chess set next to a quarter that was printed in PLA.

I have provided .stl files if you want to print your own micro chess set. The files can easily be scaled up to larger sizes to create an easier to use chess set. With a little more hand work, they can even be scaled down.

Step 1: How It Works

The resolution of extruded filament 3D printers is really quite high. I used a Makerbot Replicator 2 to make this chessboard, but it should  be possible with most low end 3D printers.

I am mainly interested in using this process to make very small robots, so I thought making a small chessboard would be a good way to find out the lower size limits of extruder 3D printing.

You cannot simply print out a small object and get consistently good results. It requires modifications in the spacing, number of objects, and printer settings to get crisp 3d prints.

Step1 pic shows the largest chess piece, a king which is .43" high by .1" in diameter. The base and head of the piece is actually hollow.

Step 2: Materials

The main thing you will need is access to a 3D Printer. I used a Makerbot Replicator 2, but other printers that extrude PLA should work.

PLA in one or two colors. I used blue and natural. The natural has the advantage that it is translucent and glows nicely when lit with LEDs.

Step 3: Printing the Chess Board in Two Colors

The chess board is designed with every other square slightly raised higher than the adjoining squares. If your printer allows it, you can print in one color and then pause and change filaments to print the raised squares in another color. If your printer won't do that, you can print the board in one color and then hand paint the recessed squares in another color. Colored nail polish works well as a paint on PLA. You can sand off any spillover with sandpaper on a flat surface.

Printing Two Colors On A Replicator 2
It is easy to print one color on a Replicator 2 and then pause mid print and change to another color. In the case of this chess board, I printed for about 17 minutes and then as soon as it started to print the raised squares I pressed the left menu arrow and clicked on change filament. This removes the extruder head from the print and allows you to change filiment color.

After the filament has been changed you can click on resume build and it will go back to printing where it left off.

Replicator 2 Settings
Print at the highest quality with a raft.
Print at the standard settings at .1mm
Make sure you have the latest version of the Makerbot software. Earlier versions do not print small things quite as well.

Step 4: Printing the Chess Pieces

The pieces were created in 123D design, a free program. A 2d profile was drawn and then Revolved to create the pieces. Its like having a lathe and turning pieces. The pieces were designed to precisely fit in the shallow holes of the board with a friction fit. Even if the board is knocked about, the pieces will stay in place.

It turns out that you cannot simply print a very small object by itself and get consistently good results. PLA requires a certain amount of time between printed layers for the layers to set up enough that they will not be distorted as the next layer is printed. Printing a single chess piece ended up with blobs instead of details and the necks of the pieces would often detach.

I tried lowering the temperature setting and that worked to some degree, but it tended to eventually clog the extruder nozzle.

I found that the best prints came about if more than one object is printed at a time and the objects are spaced about 8mm apart. 3 objects worked very well and 5 fairly well. The more pieces you print at a time, the more the play in the guide rails becomes apparent. The creeping error in mechanical inaccuracies results in less detail and blobby artifacts.

Placing the smaller pieces in between the larger ones also helps. When the printer prints the end pieces, it will print two layers before it reverses direction. This can cause distortions on the smallest pieces.

So, you should use your 3D printer software to print 3 to 5 chess pieces at a time. I also reduced the extruder speed to 50% of normal.

Replicator 2 Settings
Print at the highest quality with a raft.
To make the chess pieces hollow I set the infill at 0%.
The shells were set at 1.
The extrusion thickness was .1mm.
Make sure you have the latest version of the Makerbot software. Earlier versions do not print small things as well.

Step 4 pic shows the printed pawn and knight on a quarter.

Second pic shows 5 pieces that were printed at one time.

Step 5: Making It Smaller

The step 5 pic shows a board that I printed that was 70% of the original size. While the pieces printed out fine, the raised squares on the board closed up the holes. If you are willing to hand drill out the raised holes, you could make a chess set about the size of a quarter.

Pic 2 shows a way to make even smaller chess pieces. Molds can be made which have a higher resolution than printed parts. The raised wall are .01" but the distance between them is much less.

Pic 3 shows a pawn that was cast in Oogoo. It is .138" high x .057" wide.

Step 6: Other Possibilities

The minimum width of a single wall is about .018". This limits the size of the smallest objects that can be printed. Step 6 pic shows a set of nesting boxes on a quarter. The smallest box is about .07" x .07" with an inside cavity about .027" x .027". The largest box is about .30" x .30".

However, even though the width of the minimum extruded wall is limited to about the width of the extruder nozzle, the distance between walls is not as limited. So smaller pieces can be cast in a printed mold than those that can be printed.