I took my Singer 31-15 out and stuck my Singer 111W153 into my MUTTIN Treadle (stripped-down industrial treadle) a while back. The 111W153 is about comparable to the Consew 225. It treadled really smooth and easy with nothing under the feet, but when I put a couple of 8-9 ounce pieces of Oak-Tanned leather (about like a quality tooled belt doubled) under the foot to sew them together, I had to push so hard on the treadle pedal that I was afraid that I might break something, so I stopped the experiment. I was getting belt slippage too. I had a non-leather size 18 needle in it and was using Tex90 bonded polyester thread, so a leather-point needle may have made piercing a little better.
If you’re sewing thinner or “less-dense” materials, it should work ok. The Singer 16-188 is a medium-duty walking foot machine, which I believe, was treadled back in the day before electrification.
I have a Consew 225 that I wouldn’t trade for anything. It has a clutch motor and an 8:2 speed reducer on it, and it’s a pleasure to sew with. I’ve never used a Consew 206 (or 205, whichever it is). Lots of guys swear by the 206RB because of the reverse. The 225 doesn’t have reverse, and was patterned after the Singer 111W155, the workhorse of the Singer WF flatbed machines.
If you decide to re-home the Consew 225, give me a holler. Maybe I can trade you for something.
CD in Oklahoma