replaced Elna Supermatic drive wheel.
 

I swapped drive wheels on an Elna Supermatic this weekend.It can be done using a punch. The retaining pin is a 2mm roll pin. I had to make my punch big enough to not get caught in the center of the pin, but small enough to go through the motor shaft. No part of this was easy. There is not quite enough room for anything you want to do, and getting the drive wheel to line up to the hole in the axle while rolling it around the axle and lifting it up and down was not fun. Not for a rookie. I also included a pic of the old drive wheel with all the rubber taken on. I suppose if someone was good with making rubber, they could make a new tire. Flat spots on the tire gives one the dreaded Elna growl.

Oh yes, expect to take the base off ( three easy screws) because that little pin does like to jump down. Shake the machine around over a clean surface.

If I ever pick up one of this I will need your address for shipping purposes.

I used a 5/64" punch to drive the roll pin nearly out. The punch did get stuck, but a rubber jar gripper and a pliers easily removed it. I then rotated the drive wheel, used the rubber jar gripper and it's, and removed the roll pin.

Note: I found driving out the roll pin while machine was in standard position did not work well. I stood the machine on its nose, and everything went like clockwork.