Summary

Updated. Will post as a remix too...
Update - handle no longer requires supports to print. Has "Screwdriver-o-matic" on the side

• body has an internal spring. I did this in pla but seems to hold well so far. Print real slow with a low layer height (I used 0.12). You may get strings where the spring is to the body, but they help to stabilise the spring when the nozzle is above it printing the next layer. A lucky side effect of stringing!
  Files are Screwdriver-o-matic 5&6.

Updating again soon. With printed integral spring. if anyone's bothered! Printing it real slow...

Final version is v7. Print the body upright with no supports.
Print the handle with supports to buildplate.
Find a suitable spring (I used 9mm x 80mm).
Insert a hex bit.
Press the 2 'F's to screw in, 2 'R's to screw out.
About 7hrs print time at 0.2 height.

https://www.youtube.com/watch?v=Lv5TUKp7SvY&feature=youtu.be

(This is very much in its infancy.
Attempting to make a fully functional Yankee Screwdriver... Any remixes / help is appreciated.
Using Tinkercad.

EDIT...Still waiting for new nozzles so cant print yet. Designed with a 0.2 nozzle in mind. Uploaded v2. My aim is to have only 1 handle for both forward and reverse.

EDIT...Another one of many updates. Thinner guides in handle. 2 guides instead of 6. 8mm deep hex hole.

EDIT... V5 is now being printed. Requires a loose 80mm x 9mm spring. Fully functional reversible Yankee Screwdriver. Fingers crossed!)