[zmajmr]

Thanks, that saves me a headache and a bit of cash then . Is there no problem at all running the motor above its max rating?

I have two more questions you may be able to answer. Is the max rpm rating of the spindle itself 4000rpm or 6000rpm? I have seen references to both speeds from different sources so I am not sure which one to believe, this is the standard 120 without power chuck.

Also, do you happen to know the dimensions of the spindle bore? I know the draw tube is 20.7mm ID but there is a larger ID at the back which I do not have accurate ID measuring tools to find it, only calipers.


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I have Emco 220 P, in manual say that max RPM is 6300 , so I went to see what will happen when I try to reach it and vibrations start to increase so I concluded it is better to limit it to 4100. Originaly motor was DC and 4.4 Kw and I use 1.5 KW AC 3 phase, so my motor is little weak but I can use it. Guy that was selling machine had 5 meter bar loader so for that kind of things you realy need big motor, I manage to use 1.5 kw but I saw some situations where more poewr would be good , at leas 3 KW.

Theoretically for use of VFD you should use motor which is constructed for use with VFD which have better insulation on wingdings for higher voltage but other then that if you are not gona use more then 6000 RPM there should be not problems , I rarely go under 1000 RPM so cooling is present all the time, I thought that maybe that will be problematic but it is not, from my experience there is no problems other then to have perfectly balance spindle for such high RPM.
On my 220 P bore is 25.5 mm, for 120 I do not know.

Also google for "vfd shaft current problems", you need to install some kind of protection otherwise your bearings will be damaged in motor.
This is my thread, you will find there my DIY shaft current protection https://www.cnczone.com/forums/verti...86042-cnc.html

[Mmpie]

I have Emco 220 P, in manual say that max RPM is 6300 , so I went to see what will happen when I try to reach it and vibrations start to increase so I concluded it is better to limit it to 4100. Originaly motor was DC and 4.4 Kw and I use 1.5 KW AC 3 phase, so my motor is little weak but I can use it. Guy that was selling machine had 5 meter bar loader so for that kind of things you realy need big motor, I manage to use 1.5 kw but I saw some situations where more poewr would be good , at leas 3 KW.

Theoretically for use of VFD you should use motor which is constructed for use with VFD which have better insulation on wingdings for higher voltage but other then that if you are not gona use more then 6000 RPM there should be not problems , I rarely go under 1000 RPM so cooling is present all the time, I thought that maybe that will be problematic but it is not, from my experience there is no problems other then to have perfectly balance spindle for such high RPM.
On my 220 P bore is 25.5 mm, for 120 I do not know.

Also google for "vfd shaft current problems", you need to install some kind of protection otherwise your bearings will be damaged in motor.
This is my thread, you will find there my DIY shaft current protection https://www.cnczone.com/forums/verti...86042-cnc.html

Thanks for the heads up, I will read through your thread this evening.

The 220 is the same iron I believe? What's the hardest material you think these things can turn? I've only used it on stainless so far, which it handles easily. I need to run some stuff in en19t (4140 or 4340 I think).

It's a great little lathe anyway, I love it. As said mine was already retrofit when I bought it, it has a no frills Chinese SZGH controller which seems to work well. The X, Z and spindle motors are all encoded, I use it for rigid tapping which it does very neatly. I have some changes I want to make, including a through coolant manifold and possibly automating the tailstock. I will share more info on it when I have chance.


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[zmajmr]

Thanks for the heads up, I will read through your thread this evening.

The 220 is the same iron I believe? What's the hardest material you think these things can turn? I've only used it on stainless so far, which it handles easily. I need to run some stuff in en19t (4140 or 4340 I think).

It's a great little lathe anyway, I love it. As said mine was already retrofit when I bought it, it has a no frills Chinese SZGH controller which seems to work well. The X, Z and spindle motors are all encoded, I use it for rigid tapping which it does very neatly. I have some changes I want to make, including a through coolant manifold and possibly automating the tailstock. I will share more info on it when I have chance. Yes it is great little machine, iron base is same as on 120 , probably head stock (bearing and spindle are different).


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I turned, stainless steel, titanium grade 5, aluminum, plastic and once hardened collet from collet chuck, so it can turn lot of different materials, you just need to have right tool. I also processed tail stock in my topic It is same iron , only headstock setup is different , there is few versions with different type of bearings.