Joe90's BIG RAT Build.

[AndyUK]

Is the choice to design a machine using belts and pulleys between the stepper and ballscrew down to the size of the machine or due to what materials you intend to cut and the ability to control the speeds better.

So would a much smaller machine, say a 6040 be more likely to be driven directly than by belts and pulleys?

Its a combination of both. Lets start a pros/cons list! Hopefully everyone can add/remove. I don't think you can make a general statement about what sizes of machine would be more or less likely to have belts and pulleys?

Advantages are:

• Ability to gear up/down, particularly relevant with servos I believe.
• Ability to position motors more flexibly, potentially reducing the footprint.
• Can drive multiple screws per motor.

Disadvantages are:

• Potentially more complex system, especially if needing tensioners?
• More opportunities for backlash.

? Finger-trap potential?
? Replacement requirements?
? Expense?