Center Finder (Mittenfinder)

This small and handy assistant helps you to easily mark the center line of wooden beams or of the side faces of wooden sheets (see pictures).

Bill of materials

Besides the 3D printed part, you will need the following materials:

• 8x 608ZZ ball bearings (these will act as guides)
• 2x M8x50 screw (to fix the ball bearings)
• 2x M8 washers (to keep some clearance between the 3D print and the ball bearings)
• 1x M3 threaded brass insert 
• 1x M3x16 screw (or bit longer size to fix the pencil)
• 1x pencil (alternatively you could also use the refill of a ball pen and print a sleeve to make it fit into the central hole)

How to use

The 3D print has six through holes where you can directly screw in the M8 screws. Use two symmetric holes for centering the line. Moving the screw on one end to another whole gives an offset to the center. The holes are through holes, so that they can be used again from the other side, if they wear out eventually.

The pencil can be fixed by an M3 screw which is screwed into the M3 threaded brass insert. I used an insert here because I expect that I need to move the pencil often. If the screw is mounted directly into the plastic, the plastic hole will quickly wear out.

Maybe I will add a version for the refill of a ball pen eventually.  

Attributions

Inspired by the similar work of the “Homewerken” YouTube channel (see below). The difference is that I use through-holes, so that both sides can potentially be used and that I designed it for pencils and not ball pens.