4th axis motor size calculation for 8" chuck

[Plasmamonster]

Hello,
I am prototyping my 4th axis plasma cutter to cut pipe. The chuck size is about 8" and it weighs around 35 lbs. Assuming an 8' max length and 100lbs max. pipe weight, what would you recommend for a motor size? Obviously inertia may become an issue here. Servo stepper a must? Better to do a gear reducer or just use belt and pulley?

[adbuch]

A stepper motor will be fine. I would probably use a medium to heavy Nema 34 motor with timing belt drive. Select your reduction ratio based on your intended rotational speed and load. Rather than calculating, you could probably use a turning torque wrench or equivalent to estimate the required torque. Then back that thru your gear reduction for required motor shaft torque. I would always add in a nice safety factor, particularly since stepper motors are so cheap.

Here is a handy calculator which you may fine useful.

https://www.orientalmotor.com/motor-siz ... 8ac7b6759b

David

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