Printing printer parts

TOG’s laserjet printer was mostly working, but the two buttons on top were stuck and unusable. Each button was supposed to have a little right-angled lever connecting it to its microswitch. The problem was that one lever had come out of its mounting, and the other one was missing altogether.

Button mechanism removed, showing where the missing lever should be.

The large button has its lever; the small one doesn’t.

Missing. Gone. Not rattling around inside the printer, or sitting in a corner of the classroom. Just gone. But we have one lever left. If only there was some way we could make a copy of it…

The part is composed of a few straightforward shapes which were modelled in OpenSCAD.

Part, sketched diagram and calipers.

Measuring the part for modelling.

OpenSCAD screenshot

Building the model in OpenSCAD.

Then the design was printed on the 3D printer.

3D printer head and half-finished print.

Printing in progress.

The first print didn’t work because there was too much of an overhang. The second, improved design didn’t stick properly to the bed (small fiddly prints benefit from a brim). The third one came out nicely.

L-R: original part, two failed prints, successful print

The learning curve.

After cutting away the brim and overhang support material, the new part fits under the button…

Same button mechanism, now with two levers.

Good as new.

… and the printer buttons are working again.

Grubby, but working, printer buttons.

Printer buttons working again.

(And if your HP2200dn has also lost its button levers, the STL file is up on Thingiverse.)