4 Speed "Constant Mesh" Manual Transmission. 100% 3D Printed!

UPDATE: The main spacers were missing from the file list and have now been added. The hole in the hand crank has been adjusted to fit the input shaft. 

This is my rendition of a “constant mesh” 4 speed manual transmission gearbox. A ball-joint based selector positions the racks which mate the dog clutch disks with the driven gears, transferring their energy into the output shaft. Progresses through gear ratios of 2.5:1, 2:1.5, 1.5:2, and 1:2.5. Post your makes and comments!! Slicing orientations in photos. 

Slicing notes-

Use support material for the crank and selector. “Qty” relates to the number of instances for a given part. I don't recommend scaling this model due to its precise tolerances. 

Assembly video through the following link-

Lego L motor attachment-

Output fan attachment-