If you added a 2:1 ratio:
- To move the cutter at the same speed, the motor rpms would have to move twice as fast.
- Stepper motors lose torque with RPMs. So they would be more likely to skip.
- But the same amount of motor torque would be twice as much at the tool.
- Except for losses in the extra parts.
- There would be more backlash. The pulleys/belts have a little, and you would be tripling it to make the 2:1. If you used herringbone printed gears or something, it might be even worse.
- There would be more parts. More to assemble, more parts to fail, more parts to tune or align.
- Friction in the gears won’t be reduced by the 1:2 ratio. The reduced torque from the motors going faster would have to fight that friction. This is something we see in the Z leadscrews. Maybe it would not be an issue on X,Y.
Most people are having trouble going faster, or dealing with flex, not ultimately with torque. Those problems are solved witg CAM techniques.
In my mind, I don’t think the juice is worth the squeeze. But I only have my mind because I have not done it and I would be happy to see it. I would be interested in seeing how you did it, and any measurements showing increased force at the tool before skipping steps, and any changes in the top speed.