[allaces]

Can a 2.2kw 20,000 RPM water cooled spindle be indexed and hold that position if geared 4:1 to an R8 spindle coupled with an encoder?

[ger21]

No, as someone already told you.

[Johnboy251]

Can a 2.2kw 20,000 RPM water cooled spindle be indexed and hold that position if geared 4:1 to an R8 spindle coupled with an encoder?

In my experience, I’m pretty sure that the max allowable speed for the average encoder will be exceeded and I’m not sure that encoders exist for that rpm. How about a opto switch with a simple segmented rotor?

John


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[allaces]

ger21,

I must have missed that answer... where is it and I'm very sorry about that!

[mactec54]

In my experience, I’m pretty sure that the max allowable speed for the average encoder will be exceeded and I’m not sure that encoders exist for that rpm. How about a opto switch with a simple segmented rotor?

John


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There would be not problem with the encoder they can go way beyond any speed he would be using it at

[Johnboy251]

There would be not problem with the encoder they can go way beyond any speed he would be using it at

Ok
20,000 rpm geared 4:1 = 5000 rpm as you say - no probs with that.


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[allaces]

Ok
20,000 rpm geared 4:1 = 5000 rpm as you say - no probs with that.


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With the encoder not being an issue... is there an easy way to brake and hold the R8 spindle position using the setup I described?

[he1957]

Curious, what do you want to do?

[mactec54]

Ok
20,000 rpm geared 4:1 = 5000 rpm as you say - no probs with that.


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Not at all 5000 RPM is quite slow Encoders on the average AC servo run at 5,000 to 6,000 RPM and can go way above 20,000 RPM

[allaces]

Curious, what do you want to do?

I have a few projects that I would like to use this idea on if I could get it to work... but first... a small CNC lathe with a custom R8 spindle which would be used for machining small shafts and being able to index the spindle for machining grooves, keyways, drill holes, etc... using live tooling.

[mactec54]

With the encoder not being an issue... is there an easy way to brake and hold the R8 spindle position using the setup I described?

It's not about the Encoder that part is a none issue

No you are not going to be able to use that motor to do any kind of positioning the 2.2Kw spindle motor has a minimum speed that you can run it at the normal is 6,000 RPM there are some that have a 3000 RPM minimum so would be impossible to position anything at those speeds, spindle orientation is normally done at around 3RPM

[allaces]

It's not about the Encoder that part is a none issue

No you are not going to be able to use that motor to do any kind of positioning the 2.2Kw spindle motor has a minimum speed that you can run it at the normal is 6,000 RPM there are some that have a 3000 RPM minimum so would be impossible to position anything at those speeds, spindle orientation is normally done at around 3RPM

Thank you for that answer... I can now forget that idea and look at other more reasonable options.

[Jim Dawson]

I don't know if this motor will index but it might be worth a look https://www.automationtechnologiesin...or-and-driver/

This motor will index and turn 5000 RPM https://www.ebay.com/itm/201903367253

[Eldon_Joh]

there is no intrinsic problem with using a cheap 2.2KW Chinese spindle for indexing..

the problem is simply $$$ and time to setup a servo driver configured for an induction motor (a relatively inefficient one at that) to properly drive the motor.

most servos are permanent magnet for two reasons: higher air gap flux density (more torque per volume) and far lower losses.


a 1hp induction motor (regardless of rpm) might consume 1000 watts full load.. and 300 watts no load. and 500 watts simply delivering full load torque at zero rpm.
a permanent magnet servo might consume 900 watts when delivering 1 hp to the shaft, and 100 watts no load at nominal rpm, and 250 watts when delivering full load torque at zero rpm. its also easier to dynamically control.

[mactec54]

there is no intrinsic problem with using a cheap 2.2KW Chinese spindle for indexing..

the problem is simply $$$ and time to setup a servo driver configured for an induction motor (a relatively inefficient one at that) to properly drive the motor.

most servos are permanent magnet for two reasons: higher air gap flux density (more torque per volume) and far lower losses.


a 1hp induction motor (regardless of rpm) might consume 1000 watts full load.. and 300 watts no load. and 500 watts simply delivering full load torque at zero rpm.
a permanent magnet servo might consume 900 watts when delivering 1 hp to the shaft, and 100 watts no load at nominal rpm, and 250 watts when delivering full load torque at zero rpm. its also easier to dynamically control.

Dollars he does not have for his project, or he would of already been using a servo drive and motor, I'm not sure why you keep on posting something that is almost imposable to do

Please show us where we can find one of these magical servo drives that you can be program to run a 400Hz Ac motor