[tropostudio]

I'm researching options for 2.2kw spindles, both manual and ATC. These 2 question frequently come up from others in the same boat:

1) Which is better for machining aluminum - a 2 pole spindle at 400Hz or a 4 pole spindle at 800Hz?
2) Does the 4-pole spindle develop more torque?

This article is enlightening:
https://www.anttilehikoinen.fi/techn...good-bad-ugly/

Bottom line - 'Poles ARE NOT gears.' You need characteristic curves for the spindles you are looking at. Generalizations will likely get you into trouble in lieu of legit test data.

It's not hard to find torque and power curves for any of the 'Name Brand' spindles on the market: Colombo, Teknomotor, Mechatron, HSD, Elte, Hitec, et al. I have no clue why most of the 'Chinese' manufacturers don't supply this data on their websites or along with their seller descriptions. The few curves I've come across for the Chinese spindles are so straight/linear that it makes me wonder if they are made-up vs based on dynamometer testing. Maybe everybody or nobody is cooking the books on their numbers, but I'm not about to drop $$$ on a spindle that doesn't have legit data.

[mactec54]

I'm researching options for 2.2kw spindles, both manual and ATC. These 2 question frequently come up from others in the same boat:

1) Which is better for machining aluminum - a 2 pole spindle at 400Hz or a 4 pole spindle at 800Hz?
2) Does the 4-pole spindle develop more torque?

This article is enlightening:
https://www.anttilehikoinen.fi/techn...good-bad-ugly/

Bottom line - 'Poles ARE NOT gears.' You need characteristic curves for the spindles you are looking at. Generalizations will likely get you into trouble in lieu of legit test data.

It's not hard to find torque and power curves for any of the 'Name Brand' spindles on the market: Colombo, Teknomotor, Mechatron, HSD, Elte, Hitec, et al. I have no clue why most of the 'Chinese' manufacturers don't supply this data on their websites or along with their seller descriptions. The few curves I've come across for the Chinese spindles are so straight/linear that it makes me wonder if they are made-up vs based on dynamometer testing. Maybe everybody or nobody is cooking the books on their numbers, but I'm not about to drop $$$ on a spindle that doesn't have legit data.

You should take what you read as someone idea of what they think it is and how it works.

4 Pole is always going to be better the torque at lower speeds will be better and less chance of stalling which will happen with the 2 pole if you go to low in the RPM

2-pole motors have 1.5 ft.-lbs. of torque per horsepower.

4-pole motors have 3.0 ft.-lbs. of torque per horsepower.

[joeavaerage]

Hi,
when reading specifications of various spindles there is a trap, there are two, depending on where in the world you are, definitions of 'poles'.

In perhaps 90% of cases the term 'poles' is used as Matec has used them, ie 2 pole motor means two poles for each of the three phases. In other parts of
the world, seemingly particularly those countries that have follow the traditions of English Universities that would be described as 'one pole pair per phase'.
In some cases the difference in terminology is specifically noted, but in other cases not. In the later case it is sometimes necessary to do the calculation
max synchronous speed verses frequency applied.

As an example, I'm a fan of Mechatron Gmbh made spindles. They list in their HPF series the 'Number of poles', in the same manner as Matec uses,
but in their HPFD series they use 'Pole pairs' per the less common tradition. It can be confusing that a manufacturer would use both naming
traditions!

The upshot is that when comparing specifications and descriptions that there could be a difference in terminology and you should be aware of it.

Craig

[mactec54]

Hi,
when reading specifications of various spindles there is a trap, there are two, depending on where in the world you are, definitions of 'poles'.

In perhaps 90% of cases the term 'poles' is used as Matec has used them, ie 2 pole motor means two poles for each of the three phases. In other parts of
the world, seemingly particularly those countries that have follow the traditions of English Universities that would be described as 'one pole pair per phase'.
In some cases the difference in terminology is specifically noted, but in other cases not. In the later case it is sometimes necessary to do the calculation
max synchronous speed verses frequency applied.

As an example, I'm a fan of Mechatron Gmbh made spindles. They list in their HPF series the 'Number of poles', in the same manner as Matec uses,
but in their HPFD series they use 'Pole pairs' per the less common tradition. It can be confusing that a manufacturer would use both naming
traditions!

The upshot is that when comparing specifications and descriptions that there could be a difference in terminology and you should be aware of it.

Craig

When I used to teach this stuff, I used it both ways, giving the user / student a choice, it makes, no difference as to what way it is used or written, it is just very clear when written the way I present it. people in general get confused when it is written as 0ne Pole Pair or Two Pole Pair, unless you are working in this field then you would know, people that are in this hobby world would be lost. most don't get it no matter what way it is presented.

[Al_The_Man]

What seems to be overlooked is the fact that the number of poles are how many Magnetic Pole pairs there are within the circumference of the motor itself.
With a 2 pole motor there are only two distinct fields energized per revolution. As opposed to four pole where there are twice as many, hence the four pole has half the revolutions to a two pole for any given frequency.
Together with a higher torque.
Etc etc.