Knob with Latch (Parametric)
by CodeCreations, published
This is a parametric knob with hole cover and latch. The latch is meant to hold a door or drawer from the back so it doesn't pull out or open. The latch is engaged or released by turning the knob.
It's completely parametric (about 20 parameters), and they're all clearly explained in the code file.
VIDEO here: http://www.youtube.com/watch?v=ZVg8XCQSZRU
I'm using this as part of my parametric printer enclosure here: http://www.thingiverse.com/thing:39787
For the default settings (and the STL), you will need one M3x30 screw and three M3 nuts. This will fit an 18mm thick door (about 0.7").
1) Edit the "User-defined values" section to meet your needs.
2) Compile the object and check the echo output (rendering output) for the minimum screw length required. You may need to run the STL through netfabb -- I still need to clean up some OpenSCAD silliness.
3) Insert a screw through the top of the knob, and screw a nut onto the end. Tighten the screw until the nut is brought up into the knob and locks into place.
4) Insert the exposed threaded screw through the material you're attaching the knob to.
5) Add the latch over the end of the screw with the nut trap facing out. Add a nut and turn the the knob until the nut is brought into the latch.
6) Add another nut and tighten it down against the previously added nut to lock the latch into place. (This serves as a jam nut.)
7) Place the cap over the screw hole in the front of the knob and snap into place.