Reverse hex bit screwdriver with offset

Turn screws that are hard / impossible to reach with a regular screwdriver

I need to fix some screws at the back of my car charger but when attached to the wall it leaves me only a couple centimeters of clearance, so impossible to get your screwdriver or bitset in there. Fiddling with a hex bit in your hands get real old real fast :)

Input / output choice: ¼" Hex or ¼" Square

You can choose if you want ¼ inch hexagonal input (like a bit set to tighten Philips, Hex, Slotted, Square, Pozidriv, …) or ¼" square (like a ratchet socket wrench) for your inputs and outputs depending on which gears you place at the input and output (print some duplicates if needed). 

Translation of motion

The system needs 4 gears to translate the input correctly to the output. An example: if you want to tighten a screw, you need to twist ClockWise. Adding 4 gears makes the output rotate CounterClockWise 

• Gear 1: CW
• Gear 2: CCW
• Gear 3: CW
• Gear 4: CCW

So Gear 4 is running CounterClockWise, but as the input is facing away from you and the output is facing towards you, the motion is inverted once more, translating to a ClockWise motion and tightening the screw. 

Print settings & lubrication

I've printed with PLA on 0.20mm Quality setting in PrusaSlicer. It takes about 38 minutes to print one side of the covers (you need to print a top and bottom). No supports needed for any of the parts if you place them with their widest side on the print bed.

I found PLA had quite a bit of friction (especially if you mess around with a cordless drill as the driver it gets hot) so it's good to lubricate the print. I used some universal silicone spray to lubricate the gears, it shouldn't interact with the plastic (supposedly, please do your own research). The two holes through the middle gears take an M3 bolt & screw so your assembly stays together.

Based on original design by Carlosh Obregon

My redesign is based on the awesome model “screwdriver-accesories-by-carlosh-obregon” on Pinshape, which has the original offset model and also features a geared assembly to offset your rotation by 90° degrees. 
Link: https://pinshape.com/items/36787-3d-printed-screwdriver-accesories

Have fun assembling or disassembling your IKEA furniture / appliances / fixtures / … !