Ron, I think your bobbin thread tension may need to be adjusted for the 69 or 92 threads - One of the best Singer industrial walking foot machines I had took a drop in bobbin. More of a concern is the needle shaft - All the weight can bend a needle shaft. If the 201 is gear driven that may be more of a problem than a belt driven like a 15 clone. The industrial may have a slightly bigger shaft.

Miriam, thanks. That's good to know. I may need to also look at the bobbin carrier. The thicker threads didn't stay in the "guide" which, as you mention, could be the bobbin tension. My first thought was the thread was too thick for the carrier guide. I'll do some experimenting. I do love using the 201 not only for the larger harp. It just seems to fit my mechanical preferences. It is just so "perfect."

Ron

Those 201s are well made - you just have to love them. I like the 15s, too.