Quote Originally Posted by PotatoMill View Post
By the way can someone remember the good reason to not use overkill steppers like 8nm nema 34? It's not like they are a lot much more expensive. I read it somewhere but I can't find it.
I think Nema 34 steppers would be too large for your machine. The Load/Motor Inertia Ratio would probably be below 1:1 and therefore you're using more energy accelerating the motor shaft than you are accelerating the 40kg load!

I'm not sure about Steppers but for Servos a 5:1 Load to Motor Inertia Ratio is pretty normal, with 2-3:1 being higher performance and even 1:1 is used for super speedy machines.

A belt reduction gives you flexibility in the gear ratio. If you happen to under size the motors you can lower the gearing and get more torque with less speed, but if you over size the motors you can get some free speed!

I'm sure you can see how this becomes a hobby for many people... Haha!

Cheers,

Fenza