Torque needed for Pulsar servos

Hi guys,

I'm still planning out some upgrades to my Pulsar. The servo option for the Pulsar has 1 kw XYZ axis motors that provide 4 Nm of torque (continuous). How much torque do you think these axes should have? I've been looking at various servos and drives, but most servos of a similar size provide just over 3 Nm of torque and a higher speed.

Thanks!

Micah

I would sacrifice speed for torque in most cases, esp. as with short moves the table doesn't get up to max speed too often.

Yeah I was hoping to find something with the same or more torque as the optional servos provide, but the motor frame size has been an issue.

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Originally Posted by burbingus

Hi guys,

I'm still planning out some upgrades to my Pulsar. The servo option for the Pulsar has 1 kw XYZ axis motors that provide 4 Nm of torque (continuous). How much torque do you think these axes should have? I've been looking at various servos and drives, but most servos of a similar size provide just over 3 Nm of torque and a higher speed.

Thanks!

Micah

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1Kw is way to big for that machine a Haas Mini Mill only has 850w and that is way more machine than the Pulsar, may be the Z-axes at 1:1 may need a 1Kw but the X and Y axes 750w max, 750w are used on Bridgeport size machines

Thanks mactec, that helps me get my bearings on this a bit.

I don't know the servo size on the Torus Pro, but it doesn't have a problem snapping off a 1/2" carbide end Mill ????

It looks like the Torus Pro uses 1.2 kW servos in the same family as the Pulsar. They both make 4 Nm of torque, but the Torus version is faster, running at 3000 RPM where the Pulsar rated speed is 2500 RPM.

Quote:

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Originally Posted by burbingus

It looks like the Torus Pro uses 1.2 kW servos in the same family as the Pulsar. They both make 4 Nm of torque, but the Torus version is faster, running at 3000 RPM where the Pulsar rated speed is 2500 RPM.

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If that is peak torque then they are very poor servo motors they are using, if it is rated torque they are way over sized, I could see that size on the Z axes but not the X and Y axes

The DMM 750w has a peak torque of 7.2Nm and 2.4 Nm rated torque

I would not be worried about the torque as all modern AC Servo motors all will have around the same torque spec's

You need to be looking at Encoder count as well the higher the PPR the smoother your machine will run 16Bit Encoder is the minimum for mills

DMM | AC Servo Motor | AC SERVO DRIVE | AC SERVO MOTOR | ROTARY ENCODER

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Originally Posted by mactec54

If that is peak torque then they are very poor servo motors they are using, if it is rated torque they are way over sized, I could see that size on the Z axes but not the X and Y axes

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That's the continuous torque for those servos.

Is a brake a good idea on these?

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Originally Posted by burbingus

That's the continuous torque for those servos.

Is a brake a good idea on these?

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No you only ever have a Brake on a Zaxes and that can only activate when the power is shut down