Simple and handy centering tool for circular objects like cylinders, tins, discs...
simply draw at least 2 lines towards the center as on picture, it's quite self explanatory :-)
Side measures 10cm (3.9in) and the centering guide 15cm (5.9in)
For more precision, the guide has been offset 0.5mm to consider the pencil tip size
Fusion 360 file included so you can change size or personalize it, simply modify user parameters to change dimensions of the side parts or guide (length, width, depth)