[ballsystemlord]

So I have been looking at CNC machines, such as this one https://www.tramarindustries.com/lis...#machine-specs and I noticed that most CNC machines have big motors on them. The one linked has a 25HP motor. I expected that to turn a shaft to cut metal it would be more like a 10HP motor.

Obviously, CNC machines will use the 25HP of their motors' if they have it. But I'm rather lost as to what exactly they'll use all that HP for.

Why do CNC machines have such big motors?

Thanks!

[servtech]

So I have been looking at CNC machines, such as this one https://www.tramarindustries.com/lis...#machine-specs and I noticed that most CNC machines have big motors on them. The one linked has a 25HP motor. I expected that to turn a shaft to cut metal it would be more like a 10HP motor.

Obviously, CNC machines will use the 25HP of their motors' if they have it. But I'm rather lost as to what exactly they'll use all that HP for.

Why do CNC machines have such big motors?

Thanks!

In simple terms, they don't.
Those with "big" spindle motors tend to run at lower speeds for bigger components so able to have enough torque to cut metal.

For example, the 8000rpm speed quoted is quite high, but maybe due to gear ranges. So probably has a lot of grunt at lower spindle speeds.

[Jim Dawson]

This is why

[deadlykitten]

it is interesting how servtech talked about low rpm high torque application, and jim showed high rpm low torque

and the average user is in between / kindly

[servtech]

it is interesting how servtech talked about low rpm high torque application, and jim showed high rpm low torque

and the average user is in between / kindly

Indeed.
But for example a 5 litre diesel engine in low gear has a lot of torque. That's why you change down to climb a hill or a tractor to plough a field. It's all about getting the motor into its optimum power band. Same applies to cutting metal.

[Al_The_Man]

DC - BLDC motors exhibit the highest continuous torque at zero RPM, consult the manuf. Torque/RPM charts.

[metalmayhem]

I'd say that daewoo in the link is more designed for lower speed hogging based on it's specs . Most big insert tools for steel jobs require a lot of torque . A 4" porcupine for example needs a lot of power behind it to use the tool to it's fullest potential . Hogging needs a big spindle motor as do high speed high feed machines , their requirements are just different

[ballsystemlord]

Thanks everyone. That answers my question.