John Heisz on YouTube created this mini compass with wood ([https://www.youtube.com/watch?v=5owEwcrbe2w](https://www.youtube.com/watch?v=5owEwcrbe2w)).  He later printed it when he got a 3D printer.  I was able to find someone else's adaptation of his design on Printables but I wanted to make some changes.

• I have made the model to use a standard toilet bolt and nut (¼-20) instead of the printed threads.  The underside of the bottom has a perfect pocket for the head of the bolt.
• For the top piece is designed to accept a push pin for the pivot point.  This is a very tight fit.  I have found that not all push pins have the same length pin.  The total height of the bottom piece and the top piece is 10mm, so you should use a pin that is over 10mm. (The pin I used was 10.4mm from the plastic bit to the tip)
• The original model was 2.5mm thick.  I increased this to 5mm to accommodate the toilet bolt.  An added benefit is that it feels quite a bit stiffer. 
• I created 2 different bottom pieces:
  • For mechanical pencils - the hole is 1.2mm diameter in the model.  I use the Pentel Graphgear 1000 .5mm, but my assumption is the .7mm would work as well.  I use this for drafting and for sharp layout lines on wood projects.
  • For wood pencils (a ballpoint pen should work as well) - the hole is 2.5mm diameter in the model.  I made this for my remodel crew to use on drywall, tile, etc. where accuracy is less important.
• The original model just used an M5 nut on the printed threads.  I designed a knurled knob to fit the ¼-20 nut.  The nut goes on the top side so that it is pulled into the knob as you tighten.  I also added cut-outs inside the walls of the knob for added glue hold if you glue the nut in.

Recommendations:

• The toilet bolt will be long and should be cut.  I cut it with an angle grinder to get it done quickly, but it can easily be done with a hack saw.  I cut it just above the nut when completely assembled.  This should be done before gluing it into the bottom piece.
  • It is important to have a nut threaded onto the bolt before cutting.  Unthreading the nut after cutting will help realign the threads if they were marred or deformed.  I also recommend rounding the bolt over after cutting it to get rid of sharp edges. 
• I glued the bolt into the bottom piece, the nut into the knob, and the push-pin into the top piece.  I used super glue, but I also roughed up the nut and the bolt head with a file first to give the glue something to hold onto.
  • I don't think glue is strictly necessary.  The nut is a nice tight fit, and since it is on top of the knob it gets pulled into it as you tighten.  The bolt won't stay in place on its own if you take the knob all the way off, but that shouldn't be necessary.
• I learned the hard way to let the print bed cool completely before removing the parts.  Because they are pretty thin, they will bend if removed too early.  I printed with Bambu PLA Matte

Let me know if you would change anything!  It's the first time I have ever designed a 3d model so I'm certain there are things I could have done better :)