Questions about Induction motor
Hi!
I've looked and read several posts here on the forum and elsewhere, but I'm still in doubt about what I should use in my project.
I've had some CNC Routers, all with the famous 2.2kw water-cooled chinese spindle. But now I want to build a VMC, using epoxy granite and steel.
My inspiration has been this project https://www.cnczone.com/forums/verti...rum-posts.html , the only problem is the cost (extremely expensive) to use the Servo spindle motor as it was used in the design of the stef110.
I would like to be able to machine steel and aluminum, I see that Tormachs use 1.1kw induction motor and they can do this job well.
I found some WEG W22 of 3600 rpm and 3.7kw (5hp) that are with a good price for the budget of my project. This WEG W22 is 2 poles, but I was in doubt if there is any reason for Tormach for example to use engines with lower RPM (4 poles).
https://www.weg.net/catalog/weg/BR/e...14D/p/12219195
What do you think?
Re: Questions about Induction motor
If using a standard AC induction motor, I would go with a 4 pole motor, you can run these up to x2 freq, i.e. 3600rpm and being 4 pole they have higher torque at lower RPM's.
I have always done this with no issues.
WEG make nice motors and VFD's, BTW.
Al.
Re: Questions about Induction motor
Quote:
Originally Posted by
Al_The_Man
If using a standard AC induction motor, I would go with a 4 pole motor, you can run these up to x2 freq, i.e. 3600rpm and being 4 pole they have higher torque at lower RPM's.
I have always done this with no issues.
WEG make nice motors and VFD's, BTW.
Al.
after your answer i started to research more on the subject, the vast majority of people alert to double the frequency to double the rpm, that there are several risks of damaging the engine, so I was confused about the best AC induction motor option
Re: Questions about Induction motor
My theory is that motor manufacturers that produce 2 pole and 4 pole motors, are going to build and balance the 4 pole to the same specs as the 2 pole, so running a 4 pole at the same RPM as the 2pole is not that much of a stretch of reason!
I have done it many times over the years. Including Very old motors.
Al.
Re: Questions about Induction motor
Double check Your calculations. The torque should increase much more with higher frequency.
1 Attachment(s)
Re: Questions about Induction motor
Quote:
Originally Posted by
Algirdas
Double check Your calculations. The torque should increase much more with higher frequency.
really?
I'm no expert in this on the subject, but reading this documentation https://static.weg.net/medias/downlo...nglish-web.pdf it seems that the torque will decrease when the frequency increases by more than 1.0 factor.
I attached the chart in the post
Re: Questions about Induction motor
If you are using a WEG motor, and there is a WEG sales depot near you, check with their tech dept, The one close to me is very helpful and informative.
Al.