I received the servo motor/controller with needle positioning sensor a few days ago. Shipping took a little over a week. The packaging was good and equipment in excellent condition. I have a PFAFF 138 6/21 and I was able to mount onto the table with the original bolts. Installation was simple and only took a couple hours but could have been faster (needed to make a couple adjustments ). I ended up using the smaller pully that came in the box (I believe is 50MM). with the smaller pully installed on the motor the belt ended up being a little too long. Potentially a person can get a smaller belt or lower the motor. I was able to use the clutch motor rubber mounts that I removed from the Clutch motor mounting bracket and attached them to the servo motor mounting bracket. I then used the supplied rubber bracket mounts as shims to help drop the motor down approximately 1/2" so the belt I had would work with the smaller pully. I then attached the belt and all worked well. Two bolts came with the needle positioning sensor to attach the mounting spindle to the sewing Machine. Unfortunately neither work with the PFAFF and I needed to get another screw to bolt it on (Not the same as what you can find at a hardware store as the PFAFF screw is a touch smaller) Where the positioning sensor sits. Once mounted I had to install my own needle position sensor stabilizing hardware as the equipment provided was not made for the PFAFF 138. Unfortunately, for most machines the needle positioning mounting hardware will interfere with the bobbin winder.The motor and controller work great but as others have mentioned the manual does not show how to mount and for some could be difficult to follow. The lack of information in the manual is the only reason for the 4 star review. With the smaller pully and the adjustments that can be made with the controller, the needle can crawl or go as fast as a person would want.Hopefully this helps.
Ernesto 
