I am indeed.
The bigger V wheels sound interesting, but I’m guessing that all the mounting metalwork is different to accomodate the size so likely not a reasonable upgrade. I’ve gone to linear rail on the X which is where the bulk of the deflection problems come from.
I am running some experimental belt alternatives on my used-to-be-SO3, at the moment I have a twin 3MGT 15mm belt system which feels like you could tow a trailer with it. As noted above though, there’s a big chunk of custom metalwork on there. It’s Dan’s rail upgrade design with some extra stuff.
The next bit of measurement I’m planning to do is to figure out what the stepper motor rotation deflection is under axis loads. As I put together this new belt system it seemed that stepper deflection had become the dominant component. This is also consistent with the errors I observed between the model and measurements in my analysis of where the deflections came from.
On the bigger stepper front, it’s a real snakes & ladders thing. The bigger steppers have a higher holding torque, but at the limited voltage available from the Shapeoko driver this torque drops of very quickly as the axis movement speed goes up. Measuring the holding torque or force when the axis is stationary isn’t really useful as it’s fairly unlikely that you’d get a deflection or missed steps issue when the machine isn’t moving… Instead we’re interested in the torque supplied whilst moving and that’s a much more variable target.
All that being said, if you were to buy longer spacers, the ‘usual’ Amazon / Stepperonline replacement motor
and some 15mm GT2 belt from Powge Transmission Parts Store on Aliexpress along with a 20Tooth 8mm bore 15mm wide pulley for your stepper, that might provide some unsupported entertainment.
I would start with the X axis as this is the major source of deflection and vibration, only after that would I bother messing with the Y axes.