Thursday, May 9, 2013

3D Printed Key

Update:  This project was featured on the Make magazine website!.
OEM San Jamar Key

In my office there is a paper towel dispenser.  The key to open the dispenser was lost long ago.  So every time I want to open it, I have to jam my office key through the hole and pry until the case opens up.  Each time I risk breaking my key and it damages the dispenser.  Time to make a replacement key!  I figured this would make a good opportunity for another stab at CAD design and 3D printing.

Paper towel dispenser.

Close-up of the keyhole.

So I took a few "careful" measurements of the key hole and drew up a rough sketch.

My precision blueprints.

I spent about an hour in 123D Beta drawing up a new key.

CAD image

Then I uploaded the design to Shapeways and ordered a key.

The finished key.

Crap!!!  After I drew the outline of the key, I extruded the image in the wrong direction; creating the zig-zag portion upside down.  The key didn't fit.  Well, I really didn't feel like paying for another 3D print.  So instead I just cut off the bottom portion of the key and epoxied it back on in the right direction with some JB Weld.

The repaired key.

Hey, it works!

View of key from inside box.  Not a bad fit.

The corrected CAD file.

I fixed the CAD file and uploaded it.  Just in case someone else needs a replacement key for their San Jamar paper towel dispenser, you can purchase this key directly from Shapeways.  If you have your own 3D printer you can get the file from Thingiverse and print your own.


  1. This is immensely satisfying to me in a profoundly geeky way.

  2. heh... glad to see I'm not the only one who makes such goofs. Cool project though.

  3. Holy Hell, if you have access to a 3D printer why havn't you made a gun yet? Or have you !