Hello! 
I've been reading here for a while but this is my first post.  I've been doing some simple leather projects for a bit and have recently gotten a Singer 31-15 for free.  All in all it seems great, but I am having a hard time controlling it. I was looking for some opinions as to whether it would be worth changing out the motor for a Servo Motor.  If so, which one.  If not, any advice on how to handle the machine better? 
Thanks a lot for all the great knowledge on this site.