A tool for opening the fueltank of a brushcutter.
When trying to refuel our brushcutter (STIHL FS40) we ran into the problem of not being able to get the cap of. The reasons aren’t fully clear, but you could assume that maybe somehow the tank builds a bit of a vacuum over time when using fuel. Anyhow the cap is stuck and it’s to hard to open with your hand…

The solution: a custom key for the fuel cap!

Course of action

CAD

Because of the odd shape of the fuelcap, the measurements were taken using a piece of paper pressed onto the cap and scribbling over it with a pencil.

Using the sketch a model was made following the dimensions and adding some clearence between the fuelcap and the tool.

3D-model of the tool

To annihilate possible failure of the layer-adhesion of the 3D-printed part when twisting, M3 nuts and bolts (15mm) were used as a reinforcement. The part is then fastened to a crossdrilled steelrod with a M3 bolt (35mm).

The part was 3D-printed from black PLA with a 0.4mm nozzle and the standard layerheigth of 0.2mm. The infill was set to 100% to withstand the forces. It was then printed with a CR10-S5 3D-printer.

Assembly

Components

standard Hardware

amount	part
4x	screw M3x15mm
1x	screw M3x35mm
6x	washer
6x	nut M3
1x	steelrod: OD: 8mm length: ~165mm

3D-Prints

amount	part
1x	brushcutter-tool

All STL-files can be downloaded here