Plasterboard marking gauge

I made this marking gauge to make it easier to cut plasterboard with a cutter.

I wanted to obtain a model that was as compact as possible but nevertheless reliable in its use.

For this I use a measuring tape as a base (in my case a "Stanley FatMax auto-lock 5 m with a magnetic tip"). The magnetic tip is not essential but it will greatly facilitate the positioning of the cutting blade later.
The cut is made using a standard trapeze cutter blade.
A blocking screw (M4 x 20 slightly cut with hexagonal head) has been added to exert pressure on the tape to block it during cutting.
In order to preserve the small blocking piece, I added an M3 x 12 washer.

The different parts are fixed together using M4 x 15 round head nuts and bolts (4 units). The nuts are embedded in parts n°1, n°2 and N°6 during manufacture thanks to a printing pause. A test may be necessary to verify the ease of placing the inserts.

To change the blade, the cover (N°5) must be removed.

I also made a blade protection piece to protect the user during transport.

The adjustment of the measurement is done on the edge of parts n°2.
To make the cut, simply pass the marking gauge over the edge of the plate and exert slight pressure on the blade support and then bend the plate. A cutter in the folds will then finish the cut. To perfect the cut, a light planing stroke may be necessary.

It is understood that any other model of tape measure can be used but will require some design modifications.