Benefits of Belt Drives for Steppers

[Tool-n-Around]

.....However it looks like you've only considered torque, which is only one part of the equation.You also need to consider inertia and acceleration.

I did consider acceleration for the build and have went to lengths to make the trades to minimize moving mass while maintaining rigidity for my work envelop. I just didn't delve into it in this post because I viewed any differences in total moving mass due to motor selection to be a small factor in total system mass/inertia, so for the most part, system mass decisions were independent of motor selection other than selecting motor size/power of course. Value for money was another trade that landed me on closed loop NEMA34 steppers, as opposed to the next step to servos.

These things aside, for any given speed, the reliably acheivable acceleration is a very strong function of motor torque. I found that most motor manufacture's rule of thumb was keeping system inertia <10x that of motor rotor inertia, and in some cases for very high speed system the recommendation was <4x. In the end, it's an easily tunable parameter and unless your average tool path lengths are very short, you don't pay much of a price in run time for backing off a little on acceleration.

I studied a lot builds here and elsewhere as they relate to my machne build and was going to start a build thread but I dont think there is anything particularly novel about the design I settled on, and chose to focus more on the construction methods to optimize the mass/rigidity trades.

Thanks for the post,

Best,
Kelly