Wheel Bearing Grease Cap Fitting Tool (Mercedes) - Customisable

This is a tool to aid the fitting of a wheel bearing grease cap.  The size of the included STL file is suitable for a Mercedes W221 grease cap, and probably other Mercedes models, but the dimensions are completely customisable within the included OpenSCAD file.

The dimensions can be configured using the following parameters:
inner_diam = 59; The diameter of the inner face, i.e. the outer diameter of the grease cap.
outer_diam = 67; The diameter of the outer face.  Aim for 6-8mm difference between this and the inner_diam to ensure a wall thickness of 3-4mm, for strength.
inner_height = 18; The height to the inner side of the end face.
outer_height = 25; The overall height of the tool.  Aim for 6-8mm difference between this and the inner_height, for strength. 
inner_fillet = 3; The fillet radius of the inner corner.
outer_fillet = 1; The fillet radius of the outer corner.  Keep his value small so that the force of the hammer acts on the outer edge of the tool, rather than the end face.

The dimensions given above will make the included STL file, suitable for a Mercedes W221 grease cap.

If you set the outer_height to be the same as the inner_height, and the two fillets to be zero, you will end up with a simple open ring.  This is probably just as effective for tapping the grease cap into place with a block of wood across both edges of the ring, and would use a lot less filament!  The STL of a ring with the above diameters and a height of 18mm is included here.

If printing this on a filament (FDM) 3D printer, I recommend 100% infill.  I used ABS.

When fitting the grease cap, use a piece of wood to protect the tool while tapping the grease cap into place.  With the above dimensions the tool will be a snug fit over a Mercedes grease cap, so you can push it over the grease cap and it should stay there while you pick up your hammer and block of wood :)

CJH, March 2023.