Parallel Marking Gauge with Metric Scale

This is a sliding parallel marking gauge with a metric scale. It is very usefull in wood working to draw lines parallel to an edge.

You can download two sizes: A small ruler with a range of 150mm and a large one with 250mm. The small one fits in a 180³ build space, the large one needs a 256³ build size bed.

The ruler can be locked in position by a printed M12 bolt. The scale is quite precise but you need a calibrated printer for that. If your printer AND your filament is not calibrated, this model will NOT work.

Print preparation:
Make sure that your print bed is clean and grease-free and use a quality brand filament. Calibrate you filament otherwise the scale will be hard to read and the slider can jam.

Print settings:
For all threaded parts use a 0.12mm layer profile. Turn on supports for the bolt but make sure that you do not use supports in the threads. Both threads must not have supports.

The ruler and the slider should be printed with a 0.2mm layer settings without supports. The sliding mechanism is a tight fit but with a precision printer and with calibrated filament this will be not a problem. If you want you can use candle wax for smoother sliding action.
If you do have a problem with the tight tolerances between the ruler and the slider - the gap is only 0.05mm - then you can try to scale the slider in y-direction by 0.1%. This will make the gap larger.

I added a print profiles for the small ruler and the large one (Orca Slicer and Bambu Studio). Take a look at the profiles for more details.

An MMU or AMS is recommended to colour the scale but you can of course print everything in one colour without multi material system.

Assembly:
Deburr everything thoroughly, then assembly will be simple - put the ruler into the slider, then push the thread hexagon part from the bottom into the slider. This is a tight fit, you will need some force for that. Well, just slam it in… At last screw the bolt into the thread. Move the slider a few times to brake-in your new parallel marking gauge.

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Disclaimer:
This work by blecheimer is licensed under CC BY-NC-SA 4.0. The shown model must not be used commercially.
Copying this model to other 3D printing websites is not allowed without my permission.