Originally Posted by
leonf
I would be considering going to a belt driven 15 and a bigger motor. May be a whole lot easer. or switching hand wheels on your 15-91 to a belt drive. Not that I have done it.
I promised no more thoughts, but technically this is to LeonF. I have a 15-90 and 15-91 in the garage, and although making a 91 into a 90 might be possible, it would require finding the bobbin winder/belt guard assembly for a 90 which mounts into the same holes as the potted motor on the 91. The handwheel on the 90 looks standard and mine has the tri-pole plug so there is a specialized bracket to hold that and the motor. It looks as though you can remove the tri-pole plug assembly from a 91 to reveal a standard rail mount. I haven't taken these apart just now, but going from memory when I had the respective machines apart for cleaning.
But Leon's idea is worth digging into further.