Universal twist ballpoint pen - able to use various gel/ballpoint refills

thingiverse

This pen makes use of a twist mechanism to extend/retract a gel/ballpoint pen refill. The twist mechanism is able to use any refill whose length is between 10cm and 12cm, diameter is less than 0.65cm. eg: Fisher space pen, Parker ballpoint pen and Pilot G2 refills. Insert refill into the rear cap and use 2cm of clear Scotch tape to secure refill to rear cap. Screw rear cap into body. If you find the screw action too lose, paste some clear tape over the threads to increase friction. You can use a small spring from any old ballpoint pen to hold refill up against the rear cap. If you have big hands or are using a short refill, and you would like a longer pen, insert a 2cm length tooth pick into rear cap before inserting the refill in. Alternatively, an easy way to make a longer pen is to edit the rear cap STL file in Microsoft 3D builder, splice the rear end and stick it to the back. Make it as long as you like! The visible screw gives the user a visual cue that to work the pen, it has to be twisted. <u>The 7S version</u> The body and rear cap have 7 facets so that it doesn't roll off the table. Why 7? Google "number 7" to find out :-) <B><u>Save our Earth</u></B> If u look at today's disposable pens, nearly 80% of the material is used to support the ink refill. When the ink refill is finished, the whole thing is thrown away. Why not just replace the refills and re-use as much as possible?