Why not write about it?
I stuck a wiki and a journal together because I'm complicated like that. The journal is for passing thoughts and observations, the wiki is for more sketched out ideas.
Sometimes you'll see a link to a wiki page that hasn't been written yet. Don't worry, it will be at some point.
It's possible to convert a modern electric sewing machine to use a treadle. I have a Kenmore sewing machine (it does fancy stitches, buttonholes, etc) that I hardly ever use and so I decided on a whim to see what it would take to convert it. It was far easier than I thought.
To grok what would be involved I took the machine shell apart, but it turns out I didn't even need to do that. The machine runs off of a single motor and all I had to do was remove drive belt. If I didn't care about still having a functioning drive belt I could have just removed the side panel and cut the belt to remove it. I also could have left the belt in place, but it would be much harder to treadle with the additional resistance of the unpowered motor.
UPDATE: I discovered that I didn't even need to remove the drive belt. The knob can be simply pulled outward to disengage the electric motor. I had forgotten that was possible!
The machine with the side panel removed showing the motor with the drive belt removed.
Then it was just a matter of cutting a new treadle belt to length and slipping it over the manual turn knob. There's a ridge there to keep it from slipping off, but no groove for it to nestle in. Because of the nature of the vegan belt I'm using it still works perfectly. A traditional leather belt would not work here because there would not be enough friction to keep it from slipping.
The machine set up for treadling with half of the shell removed. There's no need to have the machine open though!
I'm using the same treadle base as I use to power my serger. It's very easy to switch machines because there's no need to attach them to the tabletop. All I needed to do was make a new size belt.
So it works with no permanent modification to the machine beside removing the belt, which can always be replaced. I can even still plug it in to power the light. It runs smoothly and easily under treadle power, almost as smoothly as my Singer. A nice improvement/hack would be to add a free-running axle so that the belt could be slipped on or off the motor as needed.
No visible modification! Just treadle love. ^__^
Any electric (but perhaps not electronic) sewing machine could probably be modified in this way! Not just this Kenmore. You can buy old treadles cheaply at garage sales or off ebay (use the local search, you don't want to ship them, they're heavy).