Aluminium FEA optimalized CNC router

[Fenza]

You could always use more powerful Stepper motors to negate the loss of torque at higher rpm. Also you could simply run your machine with higher rapids using servos so less of a gear reduction is required. 10mm pitch 10m/min rapids and a 3:1 reduction doesn't sound too bad! Ball screws have a maximum rotation speed so make sure you're not going to be over rotating them. 1,000 rpm is a pretty conservative speed but just be careful when it comes to spinning long ball screws at higher rpm.

If you'll be happy running at 3m/min then Open Loop Steppers will be a good choice. Rpm and microstepping both change the available torque so it'll be best to work out what torque will be required and choose the motor based on your calculations.

Cheers,

Fenza

[PotatoMill]

You could always use more powerful Stepper motors to negate the loss of torque at higher rpm. Also you could simply run your machine with higher rapids using servos so less of a gear reduction is required. 10mm pitch 10m/min rapids and a 3:1 reduction doesn't sound too bad! Ball screws have a maximum rotation speed so make sure you're not going to be over rotating them. 1,000 rpm is a pretty conservative speed but just be careful when it comes to spinning long ball screws at higher rpm.

If you'll be happy running at 3m/min then Open Loop Steppers will be a good choice. Rpm and microstepping both change the available torque so it'll be best to work out what torque will be required and choose the motor based on your calculations.

Cheers,

Fenza

Why not closed loop?

[Fenza]

Why not closed loop?

Personally I'm not a fan of closed loop steppers... Open loop steppers are cheap and Servos are great performers, closed loop steppers are neither...

I think it is possible for you to achieve your desired level of performance using the cheaper open loop steppers. 3Nm stepper should probably be around about right directly coupled to a 5mm ball screw.

Servos you'd be looking at 100-200W I believe.

Hope this helps!

Fenza

[remrendes]

Personally I'm not a fan of closed loop steppers... Open loop steppers are cheap and Servos are great performers, closed loop steppers are neither...
Fenza

A bigger steppers is a good idea. You can get enough torque in a no-load operation. Just you will get higher inertia as well.

[PotatoMill]

I have heard open loop steppers is not good for point to point 3D toolpaths. They loose step easy and you cant push them very well.

[magicniner]

I have heard open loop steppers is not good for point to point 3D toolpaths. They loose step easy and you cant push them very well.

Closed loop steppers are a solution looking for a problem, correctly designed open loop systems don't lose steps, if that can happen on a machine then it's badly configured or broken.
Closing the loop doesn't make a bad machine good, using the correct motors & screws and running it within it's limits does.

[Boyan Silyavski]

Closed loop steppers are a solution looking for a problem, correctly designed open loop systems don't lose steps, if that can happen on a machine then it's badly configured or broken.
Closing the loop doesn't make a bad machine good, using the correct motors & screws and running it within it's limits does.

While this is true generally, closing the loop with servos definitely makes machine faster. I also am not fan of the closed loop steppers price wise.

But if the machine will be machining Metal i dont see why at all there is a discussion for sth else than servos and closed loop. Given the price of aluminum material that will be machined and eventually a mistake made.

[Jonathan]

Closed loop steppers are a solution looking for a problem, correctly designed open loop systems don't lose steps, if that can happen on a machine then it's badly configured or broken.
Closing the loop doesn't make a bad machine good, using the correct motors & screws and running it within it's limits does.

Well said.