Description

This is a counting crab built with the PolyBriX construction set.

Its “eyes” count up to 99, by rotating its left arm. The right arm moves a unit for every 10 turns of the left arm.

The “eyebrows” are clickers that also show the current position for units and tens, respectively.

Kids can learn counting, basic gear transmission and they can even exercise their building skills by assembling this strange creature.

Printing instructions:

Walls count / Perimeters: 3
Infill pattern: Rectilinear
Infill density: 15%

No supports.

I've used PETG, but PLA will probably work as well.

Assembly instructions

Everything should be assembled like in this picture:

Make sure to clean all the contact areas of the parts (joints, shafts).

1. First, connect all the bricks, making sure that each brick will have a socket in the “up” direction.

2. Add the gear caps (C1) to one side of the shafts(S) and insert them into the holes of the bricks.

3. Add all the gears and the remaining parts as shown in the picture above.

Important : Some attention is required when adding the units final gear(the one from the right, as looking at the picture below, with digits going clockwise):

Notice that when “0” digit is up, the only tooth of the gear is pointing at 7. Make sure to first attach the add-on on the gear in this exact position, and then attach the gear to the whole mechanism, with 0 pointing up. When 0 is up, the tooth o the gear should be in the position that you see in the picture.

All the other gears can be added without any positional constraints.

When adding the clickers, make sure they are placed so that they intercalate the teeth of the gears. You may need to bend them a bit it they're too tight.

Print the frame bricks again to create the feet.

Add the feet as displayed in the cover photo.

Start counting!

The PolyBriX counting crab

0.2mm layer, 2 walls, 15% infill