Enlarged pencil holder and M5 socket head cap screw knob for "Height Gauge & Marker for Pencils"

This remix addresses two issues I had with the original model:

• My pencils were just slightly too tight of a fit in the pencil hole. I enlarged the hole in the model from having a 7mm width across flats to 7.25mm. These are Ticonderoga #2 pencils which are really common in the US so I figured others may have this issue.
• I didn't have a hex head M5 bolt so I created a knob that uses a nut and a socket head cap screw.

Printing instructions:

• PLA 
• 0.3mm layer height
• 3 perimeters
• Pencil holder: 25% infill
• Knob: 90% infill (could be 100% if your flow rate is well tuned)
• No supports

Pencil holder instructions:

• You may need to use a deburring tool on the build-plate side of the pencil hex hole.
• The M5 internal threads are unchanged from the original model. I found that using an M5 tap on the threads helps. If you don't have this I would just wax an M5 bolt and thread it in and out a few times.

Knob instructions:

• Insert a 25mm socket-head cap screw through the knob so the head seats in the round hole.
• Thread a nut onto the threads of the SHCS and align with the hex recess.
• Keeping the nut from rotating, use an allen wrench to tighten the nut into the hex recess
• Tighten good and tight. As long as you put more torque on it with the allen wrench than you can do with your fingers on the knob it should all stay in place.