3.7KW Spindle problem

[KH0UJ]

KH0UJ
Thx for ur concern. But we need an engineering fact not my opinion. Wht do u think about this calculator?!

That calculator is just for baselines sir, factors like metal material hardness, tool bit design, lubricant used while cutting, it supposed to be all added to the baselines, I`ved known "Frequency Motors" since 1998, a japanese window type (daikin) inverter AC exported here in PI, that`s the first time I encountered those motors with no LRA (Locked Rotor Ampere) on all the motors including the compressor itself, they are very efficient on power draw no questions on that, but the FLA (Full Load Ampere) on these motors should be visible on the end users to avoid over stressing it, im an HVAC engineer myself sir, that`s why im a bit familiar with these kind of motors, the only main sensor I used on these kinds of motors is the high frequency sound, whenever it drops down in tone I adjust the FRO on the machine to avoid over stressing , power meters is not so accurate to sense over stressing because it can happen in a fraction of a second, power meters respond half a second, so the quickest way on my experience so far is the sound generation on the motor. whenever it drops tone I throttle down, that`s my practice on the shop, so far so good, I never experienced yet any culprits on all 4 spindles we had, plus I coded it to my preference to basically avoid over stressing. by the way im running all 4 spindles @ full RPM on a single flute bit all the time all year round for 2 years mass producing anything the customers ordered.

[mactec54]

mactec54
I tried H39=8 and the same error gft

This was not to correct the error, just to help with noise, you can't fix something if it is damaged, with a Parameter change

It does not matter what kind of chiller you have, running these high speed spindles below the 6,000 RPM will damage them, no matter what the job you are doing with them

It's time to check the spindle windings, you can do a rough check with your meter

Check the ohm measurement of each winding
1-2
2-3
3-1
and each one to Ground, ( Spindle Body ) if all your wiring is correct then you have a ground fault somewhere

[Yasser47]

This was not to correct the error, just to help with noise, you can't fix something if it is damaged, with a Parameter change

It does not matter what kind of chiller you have, running these high speed spindles below the 6,000 RPM will damage them, no matter what the job you are doing with them

It's time to check the spindle windings, you can do a rough check with your meter

Check the ohm measurement of each winding
1-2
2-3
3-1
and each one to Ground, ( Spindle Body ) if all your wiring is correct then you have a ground fault somewhere

OK.
The staitor resistace are the same 1.1 ~ 1.2 ohm
The resitance to the ground is open circuit. I borrowed a meggar and tested every node with ground and its seems perfect. But i cant test the staitor windings with the meggar without breaking the spindle open.
The ground fault only happens when the spindle rotates with a small load or a large one it doesnt matter
Its getting me insane. Is the load i apply too large for the spindle that i fried it someway ???! This new spindle i didnt operate it under 6000 rpm yet also

[CNCMAN172]

Yasser47,
Listening to your spindle it sounds correct when you start it up if the motor was really bad highly doubtful it would sound that way and you have seen no smoke so that is a good thing. I think if you get your shielded cable installed and let the spindle run at say 6000 RPM for 10 minutes that would tell the story. The higher the RPM the more EMI that is produced. You could run an experiment do try to cut anything just turn the spindle on and let it run at 6000 rpm and see if it keeps running without a fault for several minutes. If it keeps running then slowly turn up the RPM and my guess is by the time you get to 8000 RPM it will likely fault due to EMI noise. Just run the experiment and see what happens. Just another data point.

Russ

[Yasser47]

Russ,
I will try this experiment first thing in the morning and get back to u

[Yasser47]

Yasser47,
Listening to your spindle it sounds correct when you start it up if the motor was really bad highly doubtful it would sound that way and you have seen no smoke so that is a good thing. I think if you get your shielded cable installed and let the spindle run at say 6000 RPM for 10 minutes that would tell the story. The higher the RPM the more EMI that is produced. You could run an experiment do try to cut anything just turn the spindle on and let it run at 6000 rpm and see if it keeps running without a fault for several minutes. If it keeps running then slowly turn up the RPM and my guess is by the time you get to 8000 RPM it will likely fault due to EMI noise. Just run the experiment and see what happens. Just another data point.

Russ

Sorry Russ, It stops even at very low rpm (3000) its the same as 24000

I am really concerned about my load, am I aggressive with my speeds and feeds with my spindle??!

[KH0UJ]

Sorry Russ, It stops even at very low rpm (3000) its the same as 24000

I am really concerned about my load, am I aggressive with my speeds and feeds with my spindle??!

Can you post a video on it sir? so that we have a clue on what`s really the actual scenario on your spindle, right now were just going blind speculating things that are possibly broken/ burned or whatever comes up on our minds, If you ask me I can do repairs even on the electronic hardware level, heck I can even assemble my own version of driving high frequency motors, steppers, servos or whatever loads that utilizes PWM signals to create motion

[Yasser47]

Khouj,
I have already poated a video before. Here u r

[KH0UJ]

Khouj,
I have already poated a video before. Here are u

OK i`ved seen the video sir, is it possible for you to hook up an AC clamp AMP meter on one of the harness of the 2 pole spindle? I know it`s not accurate since the clamp meter is only for 50/60 hz but it can read the numbers, even if it`s not accurate the numbers displayed on the AC clamp meter should match the the numbers in the the second pole, your spindle is a 2 pole high frequency motor, you should have 4 wires from the spindle motor going to the VFD controller, set your clmap meter to the highest AC amp. rating of the clamp meter itself. try it out and post it here whatever the result of the test

Right now im just guessing watching the video, there`s a letter T on the display, maybe the internal temperature sensor of the spindle is false sensing or damaged due to excessive vibrations of aggressive CAM programming, whatever it is you`re the one who can find out because you`re there in the actual unit.

[Yasser47]

Khouj,
The clamp meter reading is almost like the VFD reading ( slightly more with 0.2~0.4 Amps)
GFT is Diagnostic with Ground fault error, wht T do u mean?
There is no internal Temp sensor in the spindle!

[KH0UJ]

Khouj,
The clamp meter reading is almost like the VFD reading ( slightly more with 0.2~0.4 Amps)
GFT is Diagnostic with Ground fault error, wht T do u mean?
There is no internal Temp sensor in the spindle!

OK so if there`s no internal temp sensor on your spindle then I guess the windings on that got partially shorted then, you cant verify it thru a normal multimeter, you need an inductance meter to do the checking of a partially shorted high frequency motor winding, mega ohm meter (megger) does`nt get it either, it`s only for the conventional AC/DC motor ground fault check and absolutely not on the almost short resistance winding of a frequency motor, if you can borrow an inductance meter I think you should do that, just a heads up on your side sir, it`s so easy to rewind a high frequency motor to be honest, it`s just 20-30 loops of magnet wires each in every face of it, in your case there are 4 faces, the 2 faces are just connected in series to form the 1st pole, the same as the second pole.

[mactec54]

OK so if there`s no internal temp sensor on your spindle then I guess the windings on that got partially shorted then, you cant verify it thru a normal multimeter, you need an inductance meter to do the checking of a partially shorted high frequency motor winding, mega ohm meter (megger) does`nt get it either, it`s only for the conventional AC/DC motor ground fault check and absolutely not on the almost short resistance winding of a frequency motor, if you can borrow an inductance meter I think you should do that, just a heads up on your side sir, it`s so easy to rewind a high frequency motor to be honest, it`s just 20-30 loops of magnet wires each in every face of it, in your case there are 4 faces, the 2 faces are just connected in series to form the 1st pole, the same as the second pole.

He checked the windings and they are fine

[mactec54]

Khouj,
The clamp meter reading is almost like the VFD reading ( slightly more with 0.2~0.4 Amps)
GFT is Diagnostic with Ground fault error, wht T do u mean?
There is no internal Temp sensor in the spindle!

Does your spindle have ceramic Bearings

[CNCMAN172]

Yasser47,

Sorry Russ, It stops even at very low rpm (3000) its the same as 24000

This is not good news, this seems to indicate you have an issue with the spindle itself. As someone else said it could be an actual ground fault in the motor, but you seem to have tested that with your meter and the windings seems to be about the correct ohms. Wonder if something has broken lose inside the spindle causing the short, very interesting issue.

I am really concerned about my load, am I aggressive with my speeds and feeds with my spindle??!

This can not be your speeds and feeds or the load. Keep in mind it is faulting with no load even and 6000 RPM and in a few seconds. It is possible you got too aggressive with the spindle and it got hot and damaged some of the insulation on the windings. You have already tried another VFD that was new, so this is looking more and more like the spindle. I would still change the cable to a shielded version, something like the OLFLEX stuff designed for VFD and Motors, the exact cable depends on the size of the spindle the 16 AWG is for the typical 2.2KW spindle.

Lapp Kabel 7416048 16/4C+18/1P OLFLEX VFD Shielded Power+Signal Cable 600V /10ft | eBay

Russ

[KH0UJ]

OK so I researched a bit on 3.7KW 24K RPM spindles and I noticed something odd on his present data, he`s using a clamp meter on his amperage test



This is his data on the motor @ no load state, this is after he got ground faults.



And this is the data I researched, though im not really sure it`s the same motor he got, but a huge NO LOAD amperage on his current motor data is a bit higher than the factory state, and yes he test the windings on it but only on a multimeter which for me not really that accurate because he can only read the resistance of the coils, how about the inductance? I do think that it`s motor design is similar to the motors used in quadcopters which I rewinded several motors myself due to it`s already partially shorted, not detectable on just an ordinary meter but an inductance meter, I have a home made inductance meter here that can detect faults on even just 6 turns of magnet wires in a ferrite core, totally undetectable on an ordinary multimeter, scenario 2 semi stuck ball bearing, I can hear the the spindle startup perfectly fine by just listening the high frequency sound generated, so yes it`s only him that can really pin point on what`s really the fault on his spindle because he`s there in actual it`s an interesting topic by the way because im learning on it too

[Yasser47]

KH0UJ,
The spindle bearings are excellent, the model u got isnt my spindle however this amp are at 18,000 RPM, if i get to 24,000 it get to 1.5 ~ 1.6 amps

[Yasser47]

OK, I lost my mind Already, I got another spindle today and tried it, Guess wht, GFT, again!!!!

I will go now to get a braided shielded cable and try again and get back to u ASAP

[KH0UJ]

KH0UJ,
The spindle bearings are excellent, the model u got isnt my spindle however this amp are at 18,000 RPM, if i get to 24,000 it get to 1.5 ~ 1.6 amps

OK now let`s go back to square one then because your spindle windings are fine interesting.....now let`s think of another angle on what`s triggering the ground fault on the controller, it`s your second new controller right?

[mactec54]

OK, I lost my mind Already, I got another spindle today and tried it, Guess wht, GFT, again!!!!

I will go now to get a braided shielded cable and try again and get back to u ASAP

Like I said long ago if you don't use the Shielded cable correctly it will not solve anything

You have not shown how you have wired the VFD Drive I asked you this some time ago with a Photo I can tell you if it is correct or not

As I said all along you have a wiring Problem

[mactec54]

OK now let`s go back to square one then because your spindle windings are fine interesting.....now let`s think of another angle on what`s triggering the ground fault on the controller, it`s your second new controller right?

It was obvious that there was nothing wrong with his spindle windings, He has a wiring problem