4mm bit storage and ratcheting driver set

prusaprinters

This is a remix of AMT's excellent tiny travel screw driver.I have quite a few 4mm bits, and was always having problem storing them, but can't find a compact way to do it.  Therefore seeing AMT's tiny driver and bit set, it pushed me to come up with this design. I added a few type of bit holders, and called it cylinders ( from revolvers) . Each cylinder can hold 6~7 bits, and when you use double cylinder it can hold 12 bits. Then there are 2 deferent style of case that can hold cylinders. both style comes with short and long ones, which holds single and double cylinders. Casing all have threads at top and bottom, so you can connect multiple casing together to store more bits. There is also end cap and bit holder caps that can also be attached to casing.  You can put 4mm bits and use them as screw driver for light workBut for heavier work, you will want to make use of a 4mm bit extender - I bought this harbor freight set and has a long 4mm bit extender, and it makes for a solid core for heavy duty screw driver usage. ===== Ratchet =====I have also added a reversible ratchet that can be screwed onto the bit holder - it is not perfect, you still need to press on the direction dial for ratchet to work correctly. But for light work it is still helpful. Ratchet will require 2x m2 5mm screw to secure the top cap to the body. And here is how to put this ratchet together.  ===== printing =====Please first print the "4mm bit cylinder short" as a test print, and test the fit of 4mm bit in the cylinder. You want to adjust the scale percentage, and make sure the bit fits  snug but still easy to put bit in and take bit out.Once you get the scale right, print all other pieces with the same scale percentage. ===== mix and match to hold your bits! =====The long case can hold either 1 double cylinder or 2 short cylinder. double cylinder could be good if you are using 4mm extender as a center shaft, but if you are just storing bits, 2 short cylinder can hold 14 bits instead of 12 bits in a long case. Also if you are using 4mm extender, it is best to use the hex style case. It is easier to tell the center hole is lined up in the hex style cases. Mix and match differnt casing configuration to hold all of your 4mm bits!