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Author Topic: Spindle turns on and makes noise but it doesn't spin  (Read 3807 times)

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Re: Spindle turns on and makes noise but it doesn't spin
« Reply #10 on: November 22, 2014, 02:46:27 PM »
Okay so I just did some testings and this is odd.

At 400hz the shaft is stiff and I can hardly spin it using my hand. So its locked.

I turned the spindle on in Mach3. Set the Hz on the panel to 100 (since at 400hz I couldn't manually spin it without a lot of resistance) and went with my finger and spun the spindle myself. After a little spin it started spinning by itself. Switching the hz on the panel made it spin faster/slower like it should.



« Last Edit: November 22, 2014, 02:49:03 PM by Demanth »
Re: Spindle turns on and makes noise but it doesn't spin
« Reply #11 on: November 23, 2014, 07:11:25 PM »
You either have a open motor winding or bad connection between the drive and motor. The motor connector plug has 4 female terminals pins and only 3 are used for the motor windings. My bet is the motor connector plug is miswired. Meaning only 2 of the 3 terminal pins are connected to the motor windings. Its very easy to miswire the terminal pins. The Chinese spindle motors don't have connection diagrams, you have to remove the screws on the motor male connector plug and lift it up to see what 3 pins are being used. Then solder the leads coming from the drive on the corresponding female connector pins.  

At 400hz the motor rotor is locked with full 230V... at 100hz its only about 57V so its easier to turn by hand. A 3 phase motor will run on 2 phases if spun to start however, it will quickly damage the motor because of overcurrent on the 2 powered phases. That's why the red "Trip" light is flickering on the drive.

If the drive overcurrent protection parameters are set correctly for the motor full load amps the drive should trip on overcurrent.
« Last Edit: November 23, 2014, 07:16:10 PM by geh7552 »
Re: Spindle turns on and makes noise but it doesn't spin
« Reply #12 on: November 23, 2014, 07:18:03 PM »
You either have a open motor winding or bad connection between the drive and motor. The motor connector plug has 4 female terminals pins and only 3 are used for the motor windings. My bet is the motor connector plug is miswired. Meaning only 2 of the 3 terminal pins are connected to the motor windings. Its very easy to miswire the terminal pins. The Chinese spindle motors don't have connection diagrams, you have to remove the screws on the motor male connector plug and lift it up to see what 3 pins are being used. Then solder the leads coming from the drive on the corresponding female connector pins. 

At 400hz the motor rotor is locked with full 230V... at 100hz its only about 57V so its easier to turn by hand. A 3 phase motor will run on 2 phases if spun to start however, it will quickly damage the motor because of overcurrent on the 2 powered phases. That's why the red "Trip" light is flickering on the drive.

If the drive overcurrent protection parameters are set correctly for the motor full load amps the drive should trip on overcurrent.

Thanks a lot for your input and help. I guess I will talk to the seller before messing with the wires.

Oh and the Trip light stays off once I make it start spinning.
« Last Edit: November 23, 2014, 07:25:19 PM by Demanth »
Re: Spindle turns on and makes noise but it doesn't spin
« Reply #13 on: November 23, 2014, 07:35:52 PM »
That's because spinning by hand you mitigated the rotor starting inertia and once turning the powered 2 phases can overcome the rotor mass so the drive current is pretty low. Probably around 0.2 amps so no red tripping light. As the motor is loaded such as cutting with a tool bit will cause the amps to increase to the point of tripping the drive or just stall the motor. That's why the trip light is flickering trying to start without manually spinning the rotor.  

I seen two identical 2.2kw spindle motors wired differently at the motor connector plugs. Apparently the Chinese don't have standards.  :o  The CNC machine should have been tested before it left the factory.

« Last Edit: November 23, 2014, 07:43:59 PM by geh7552 »