Trammel / large compasses

To build it you need:

• one M6 x 20mm grub screw but you can also use a normal M6 screw and make it pointy with a drill and some sandpaper
• one O ring (14 x 2.5mm or 17 x 2.5mm) to hold the pen (or a other rubber band)
• one stick 10mm x 20mm and as long as you need, my is 1m 
• one pencil (around 9mm in diameter works good, but is not critical)

If you want easy rotating tops you also need:

• two M4 x 16mm cylinder head screw (a other small head screw works also fine)
• two M4 nut 
• two ball bearing 608 ZZ (8mm x 22mm x 7mm)

To build it:

• Insert the grub screw into the “PinHolder”
• Rotating head
  • Insert the M4 x 16mm cylinder head screw into the “Cap”
  • put one “BallBearingsHolder” on top of the “Cap” onto the screw
  • put the ball bearing onto the “BallBearingsHolder” 
  • add a second “BallBearingsHolder” onto the ball bearing
  • fix the ball bearing between the “BallBearingsHolder” and on the cap with the M4 nut
  • press the “Head” onto the ball bearing
• insert your stick into the “PenHolder” and “PinHolder” and screw on the head assembly
• put on the pen with the O ring

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