This thing goes into the latch hole of the door to avoid the door latching.
ReadMe.txt has additional instructions or comments.
Update 2018-10-05: I have just uploaded a version 2. Modifications include update to freeCAD file format, hole for for the ring, thicker backplate (0.5 mm more). When printing it I chose 0.15 mm. I decided to do it again because the one we have broke.
Update 2018-10-05: turns out 0.5 mm is too much. I have uploaded a version with a 2mm thick base. Rounded edges are now 0.9 mm radius to accommodate.
To avoid support material leave the largest flat area to the bed.
Tape and bend
The part goes straight out. Will need bending.
Once confirmed that it works then with the door closed and the device inside the latch slightly bend the material so that the door can easily "flow" over the surface.
Also if the fitting is not tight to the latch hole the device will fall out. To avoid this you can adjust the size or you can just wind some tape around. I recommend Plumbers or electricians tape. A contrast colour with the material works well. Give it two turns and test.
I measured the distance between the door and and the door frame when closed. That will do the flat rectangle base.
I measured the size of the latch hole. Made mine about 3 mm smaller than that. Measure the depth. The part of the device that goes into the latch hole should be slightly smaller and does not need to go all the way down.
Length is chosen randomly. Just as long as it does not go out much.
Using freeCAD the process is drawing the rectangle for the "hole filling" part symmetrical to the origin, padging it the given length. On the surface generated I created a bigger rectangle with an added edge to the first extrusion. Padded that. then I positioned the hole and made a cut. Lastly selected the larger sufaces of the large rectangle and the side faces of the hole filling part and rounded the edges.