Greeting folks!
I have a working 1908 Singer 29-4 Treadle which I picked up for $100 (ducking)
I can say that I have yet to find it's capacity.
I have tested sewing 16 layers of HEAVY canvas (no problemo..)
I have tested 3 layers of 6oz leather
Tonight I am testing 2 layers of 12oz
With that said, ALL of the feedback that I have been getting from folks supposedly "in the know" have said it was only designed for "patching" or small run, short use activities (hence the tiny bobbin)
I have been told that the 29K is a more robust and capable machine.
I do know that the "consew" line of chinese imports are a virtual clone of the Singer 29K
Your mileage may vary.
Steve