Elna Pinion Gear 403050-20

thingiverse

Four versions of this gear are found here in two versions (inset hex nuts and threaded set screw holes). Slight modifications were made so it can be printed upright on the printer without supports. It was brought to my attention that this gear is described on USA websites as having 18 teeth while European websites specify 15 teeth. Both versions which have the same part number are included here. Count the teeth on your old gear and select the correct file. The set screw hole version looks very much like the original with the set screws being threaded into the body. You will need to cut the threads with a 4mm tap or try slowly screwing in the set screw. I did not pretap them in the model as that isn't always the best for small screws. Alternately, a 4mm threaded insert applied with heat would provide metal to metal contact. I prefer the second version with captive hex nuts. Two 4mm nut are inserted at the top with the flats to the sides. A little dish detergent may help. It is a tight squeeze but it does go in. I used the flat of a pair of pliers to gently tap it down flush and then a small flat blade screwdriver to drive it home with another couple of taps. The nut can't go in too far as it will bottom out in a nut shapped pocket. The hole should line up perfectly with the nut. A small drop of threadlocker will help prevent vibration from losening up the set screw. Normally I test my creations in one of our Elnas before posting but in this instance I don't want to dissemble a working machine. What I did was print the mirror image of the gear to see how well it meshed with the original. Please comment and let me know if this worked for you. Thanks.