Spindle not running - Need Help

[Lumiyo Ben]

Hi MYCNC community,

Im having trouble with getting my spindle to spin up. I don't really have any knowledge of how my machine works and would love some help on this.

Ive attached a couple of pictures of where i think the issue is being caused.

There is a flashing red light on D17 on one of the boards which wasn't showing yesterday.

This light stops flashing if the usb lead is removed.

Thanks for reading.

Any advise would be amazing

Cheers

Ben

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[Doddy]

I'm cautious about offering any advice here, because I fear this could run and run and go nowhere, and you're rather too far away for me to eyeball.

Has the spindle operated in the past?, i.e. is this a newly developed problem, or not? - that'd help us to understand a starting point.

You show an image of the VFD commanding a forward rotation at 400Hz (typically 24k rpm for a 2-pole spindle) - but the spindle doesn't rotate?, that's an alarm bell to me - irrespective of the behaviour of the flashing light on the USB BoB - if the VFD is commanding rotation and the spindle isn't moving, I'd be worried about either the VFD or the spindle. However, I'd expect the VFD to display a fault in either case.

Edit: https://www.automationtechnologiesinc.com/wp-content/uploads/downloads/2012/11/USB-Motion-Card-AKZ250-Manual-v1.17-EN.pdf looks to refer to a similar BoB, with a statement "Status indicator LED can be useful to show the USB connection, and working status by flashing."

[Lumiyo Ben]

Thanks Doddy. We have been using the machine every day for several months without any problem with the spindle. We used it on Friday but when we started it up on Saturday it would not spin up. Mach3 shows the spindle should be spinning but it is not. Thanks again. B

[Doddy]

So, assuming you're running Mach3, can you enter an MDI command "M3 S18000" and the VFD (the black box connected to the spindle with the red 7-segment display) will display "F300.0" and indicate the "For" LED?, and the Spindle still refuses to spin?

[Lumiyo Ben]

So, assuming you're running Mach3, can you enter an MDI command "M3 S18000" and the VFD (the black box connected to the spindle with the red 7-segment display) will display "F300.0" and indicate the "For" LED?, and the Spindle still refuses to spin?

I have entered the code into mach3. the spindle speed bar is flashing yellow which happens when the spindle is moving.
The code on the VFD is showing A0000
2918129182

Thanks again for your help with this

Cheers Ben

[Doddy]

Ugh. Marchant Dice?, I had one of their machines, once.

Curiously - Mach3 is limiting the speed to 2400rpm (that might be your pulley set-up). With the "A" display, you're displaying the current taken by the spindle. The previous post, where your showed a display of "F400.0" was showing the frequency of the motor... The "F" display indicates the frequency driven to the spindle, whereas we can't deduce much from the "A" display (other than the VFD/spindle should be operating). If you hit the (I think) "Shift/>>>>" key to toggle through the displayable parameters, can you get to the "F" display and report the value therein? or press until the LED marked "RPM" is illuminated then report the value there?

Why I'm asking this is to confirm that the VFD is presenting a demand to the spindle (or should be) - and I'm using your first post where you included a photo of the VFD presenting a 400Hz demand to the spindle. In which case we can disregard everything else except the VFD and spindle (and the cabling between).

At that point I'd be recommending that with the power removed you examine the cabling from the VFD output to the spindle, and what I expect is a connector on the end of that cable where it enters the spindle. If you're able to test electrical continuity I'd be asking you to check the spindle coils (if the spindle has a connector on it, again, powered-off, remove the connector, and you will likely find 4 pins - check for low continuity of a couple of Ohms between each permutation of three of the pins (the fourth is likely disconnected). Whilst you have the connector removed from the spindle then check continuity of the cable back to the VFD. My fear is either the VFD or the Spindle is buggered. If you get a similar, low resistance between three pins on the spindle - chances are the spindle is okay, if you have continuity (low resistance) in the cable between the VFD and the spindle, then the cables okay... which leaves the VFD. Testing that is okay if you know what you're doing with a meter, and can work safely at mains voltages. If you know that, and you can set your VFD to 50Hz (looking at the Mach3 screen shot - MDI: "MD S600") then you can work that out for yourself - you're looking for an AC waveform of around 380V (pk-pk) or 240Vrms between the U-V/V-W/W-U terminals on the VFD output - with the spindle connected!

EDIT: Really stupid question - there's no E-stop wired to the VFD is there?... if there was the VFD should display ES, or similar.

[Lumiyo Ben]

Ugh. Marchant Dice?, I had one of their machines, once.

Curiously - Mach3 is limiting the speed to 2400rpm (that might be your pulley set-up). With the "A" display, you're displaying the current taken by the spindle. The previous post, where your showed a display of "F400.0" was showing the frequency of the motor... The "F" display indicates the frequency driven to the spindle, whereas we can't deduce much from the "A" display (other than the VFD/spindle should be operating). If you hit the (I think) "Shift/>>>>" key to toggle through the displayable parameters, can you get to the "F" display and report the value therein? or press until the LED marked "RPM" is illuminated then report the value there?

Why I'm asking this is to confirm that the VFD is presenting a demand to the spindle (or should be) - and I'm using your first post where you included a photo of the VFD presenting a 400Hz demand to the spindle. In which case we can disregard everything else except the VFD and spindle (and the cabling between).

At that point I'd be recommending that with the power removed you examine the cabling from the VFD output to the spindle, and what I expect is a connector on the end of that cable where it enters the spindle. If you're able to test electrical continuity I'd be asking you to check the spindle coils (if the spindle has a connector on it, again, powered-off, remove the connector, and you will likely find 4 pins - check for low continuity of a couple of Ohms between each permutation of three of the pins (the fourth is likely disconnected). Whilst you have the connector removed from the spindle then check continuity of the cable back to the VFD. My fear is either the VFD or the Spindle is buggered. If you get a similar, low resistance between three pins on the spindle - chances are the spindle is okay, if you have continuity (low resistance) in the cable between the VFD and the spindle, then the cables okay... which leaves the VFD. Testing that is okay if you know what you're doing with a meter, and can work safely at mains voltages. If you know that, and you can set your VFD to 50Hz (looking at the Mach3 screen shot - MDI: "MD S600") then you can work that out for yourself - you're looking for an AC waveform of around 380V (pk-pk) or 240Vrms between the U-V/V-W/W-U terminals on the VFD output - with the spindle connected!

EDIT: Really stupid question - there's no E-stop wired to the VFD is there?... if there was the VFD should display ES, or similar.

Hi Doddy,

Thanks for all this info. Ill work through it now and see what i can find out.

Marchant dice are terrible - i've not been able to get any support from them at all about the machine.

Cheers

Ben

[Lumiyo Ben]

Hi Doddy,

The F display on the VFD is currently showing as F90.00

[Doddy]

To the best of my understanding then, the vfd is commanding a rotation on the spindle, but you say there’s no rotation and the indicated current drawn by the spindle is zero. At this point I’d be checking the continuity as above, de powered of course.

A photo of the spindle and wiring to it could be interesting, if not useful.

[Doddy]

... and I really am asleep... I was trying to get to F050, which is 1/8 of 400hz, which would be MDI : M3 S300, not 600, sorry. But that’s not strictly important here

[Lumiyo Ben]

291892918829190Hi Doddy,

Going to check the continuity on the cables now.
I’ve attached a couple of pictures of the spindle and the wires

Thanks again for your help

[Doddy]

Thanks for those images, confirms m y assumption over the choice of spindle. Also indicates you have a small setup issue with Mach3 which is unimportant at this time. Your first post shows the VFD illuminating the FORward LED - I'm assuming you can drive this with an M3 command and extinguish it with an M5... thats really the last bit that would convince me that you have Mach3 control onto the VFD and that the problem lies in the VFD/wiring/spindle.

Actually, you can check the continuity of the loom and spindle through those three sockets on the connector in the photo - just check for a couple of ohms between each pair (1-2, 2-3, 1-3).

[Lumiyo Ben]

I’ve just checked the wires running from the spindle to the VFD and the three sockets on the connector and I’m getting a consistent reading on all of them.

Does this mean it could be a MACH3 issue?

Cheers
Ben

[Doddy]

I don't think this is a Mach3 issue. You've said already that you can command a forward rotation from Mach3 onto the VFD (first post - "FOR" LED illuminated, "F400.0" commanding full speed rotation. No spindle movement.

What were the measurements on the connector?

[Lumiyo Ben]

Ok just hoping it might not be a hardware issue

Here are the readings from the connector

1825
1780
1755

[Doddy]

I'm assuming that those are the readings from the 3-pin connector, with the other end connected to the spindle. And that those are in the milli-Ohm range?

I'm asking because I've just been to measure my 2.2kW spindle...

29191

All combinations between three pins were measured at 1.6 Ohm. (or, broadly speaking, 1600 milli Ohm) as...

29193

29192

A number of 1825, 1780 or 1755 would make sense, if on a milli-Ohm range (very unusual / expensive meter) - or possible presented as "1.825" Ohm?,

A value of 1825 Ohm would concern me somewhat.

[Lumiyo Ben]

I'm assuming that those are the readings from the 3-pin connector, with the other end connected to the spindle. And that those are in the milli-Ohm range?

I'm asking because I've just been to measure my 2.2kW spindle...

29191

All combinations between three pins were measured at 1.6 Ohm. (or, broadly speaking, 1600 milli Ohm) as...

29193

29192

A number of 1825, 1780 or 1755 would make sense, if on a milli-Ohm range (very unusual / expensive meter) - or possible presented as "1.825" Ohm?,

A value of 1825 Ohm would concern me somewhat.

I’ve double checked the readings and they are showing the same. The metre is showing its reading at milli-Ohm

[Doddy]

Ah, good... I did want to confirm that - it's unusual (or maybe I'm behind the times) to get general purpose DMMs with milli-Ohm ranges. Never mind, onwards and upwards.

I'm assuming that you're confident then that the three phases of the motor are all in the same region of around 1.6-1.8 Ohm then that's largely convinced me that the spindle is okay - and that's no surprise, there's not usually problems with the spindle I would always check the harness (cables fracture over time if moved) - but I think you've discounted that. The weak link in the chain would always be the power electronics on the VFD.

If you had a working system (ironic, I know) I'd recommend reconfiguring the VFD to drive it manually from the VFD just to remove every other variable from the equation, but not being able to test the spindle means this is likely to just add confusion to the situation. I'm depending on your description that you've been able to present demands from Mach to the VFD (creating the rotational demands - the 'F400.0'/'F090.0' etc previously, and the indication of a forward command ('FOR' LED on the first picture... though you've not re-confirmed that in a later question).

At this point I personally would be measuring the 3-phase outputs from the VFD to the spindle, with a rotational demand of "F050.0" (M3 S300, I think we got to). But, this is something you should only attempt if you know what you're doing. My thoughts are, though, that you're likely to see basically no volts on the 3-phase output, then I'd be into the VFD to check the internal DC bus on the power board. But, unless you're confident with what you're doing I cannot recommend that you try this - it's potentially hazardous. Are you confident working on powered mains supplies?

[Lumiyo Ben]

Ah, good... I did want to confirm that - it's unusual (or maybe I'm behind the times) to get general purpose DMMs with milli-Ohm ranges. Never mind, onwards and upwards.

I'm assuming that you're confident then that the three phases of the motor are all in the same region of around 1.6-1.8 Ohm then that's largely convinced me that the spindle is okay - and that's no surprise, there's not usually problems with the spindle I would always check the harness (cables fracture over time if moved) - but I think you've discounted that. The weak link in the chain would always be the power electronics on the VFD.

If you had a working system (ironic, I know) I'd recommend reconfiguring the VFD to drive it manually from the VFD just to remove every other variable from the equation, but not being able to test the spindle means this is likely to just add confusion to the situation. I'm depending on your description that you've been able to present demands from Mach to the VFD (creating the rotational demands - the 'F400.0'/'F090.0' etc previously, and the indication of a forward command ('FOR' LED on the first picture... though you've not re-confirmed that in a later question).

At this point I personally would be measuring the 3-phase outputs from the VFD to the spindle, with a rotational demand of "F050.0" (M3 S300, I think we got to). But, this is something you should only attempt if you know what you're doing. My thoughts are, though, that you're likely to see basically no volts on the 3-phase output, then I'd be into the VFD to check the internal DC bus on the power board. But, unless you're confident with what you're doing I cannot recommend that you try this - it's potentially hazardous. Are you confident working on powered mains supplies?

I’m really not confident doing this test. But thank you so much for your help.

Cheers
Ben

[Doddy]

Here's a thought - with power removed, remove the two screws on the front of the VFD - not the ones mounting this to the back plate, but there's a removable panel on the front of the VFD - lower half. remove those and the panel slides off - exposing the screw terminals. Get a photo of that.

EDIT: I'm clutching at straws of what you can examine safely at this point. It'd be embarrassing if one of the terminals had come loose from there.