# Problem with CNCest 6040t spindle whining but not spinning



## brad1000 (Feb 28, 2021)

Had and been using my cncest 6040 4 axis 1.5kw CNC for like 2 months, then out of nowhere when I go to use it from computer and start the spindle, it whines but doesn't spin. Yes I can turn the spindle manually while it is winding but will not spin even with that "help" (thinking maybe it was stuck but no)
I reset the control bow, but to no avail. Tried turning the spindle on in both PC mode and manual mode with same result. I assume the spindle windings are bad but I wanted to ohm out the wiring from the spindle connection to the control box. This is where I need help (and if you think there is something else I am missing to cause this).
There are 4 lead holes on spindle connection and 5 on the control box side. I put one probe in each hole of the control side (5 holes) and checked each of the 4 connections on spindle side. Only 2 of the 5 holes on control side gave a reading of connectivity with one (different one for each of the 2) of the 4 holes on spindle side.
My guess would of been 4 of the connections on control side would of had their own connectivity reading with their own on spindle side. Maybe I am wrong, not sure.
none of the wiring is tight, I don't see any signs of pulling, wear, or tear in the wire. Just want to rule it out before I go buying a new spindle.

Also, if I have to buy a new spindle. I am curious as to can I upgrade both the control box and spindle in one shot. This is a 4 axis so it does have an A axis. along with this question goes the obvious question of could I use existing wiring for that upgrade.
I cannot reach the seller any longer. Ignoring my emails. Don't know how to reach any mfg of this unit. Don't see a part storefront so basically on my own I guess..


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## old55 (Aug 11, 2013)

Welcome to the forum


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## TimPa (Jan 4, 2011)

you cannot get an accurate ohm reading on the motor, while it is still connected to other circuitry. what yu could do, if you feel comfortable with it, would be to take voltage readings on the same electrical connection of the motor, when it should be running. 

are there fuses in-line with the motor wiring, does the vfd appear to be operating?

hopefully others will also chime in soon to help you troubleshoot...


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## difalkner (Jan 3, 2012)

To Tim's point, are you getting all three legs out of the VFD? I would disconnect the spindle and see if you're getting 240v across all three legs of the VFD.

David


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## Cncest (Apr 26, 2020)

I had a similar problem. Cncest 6040 spindle stopped running. Turned out it was a bad wire between control box and the spindle. The wire broke right at the flex point in the cable tray.


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## brad1000 (Feb 28, 2021)

TimPa said:


> you cannot get an accurate ohm reading on the motor, while it is still connected to other circuitry. what yu could do, if you feel comfortable with it, would be to take voltage readings on the same electrical connection of the motor, when it should be running.
> 
> are there fuses in-line with the motor wiring, does the vfd appear to be operating?
> 
> hopefully others will also chime in soon to help you troubleshoot...


Appreciate the reply, yeah I know about ohming out wiring just wondering why I am not getting 4 readings on one end.
I will take a pic after work today of both ends of the spindle wire and post it here.

Connection going into the spindle is 4 female "holes" (for lack of better word) and connection on control box side hase 5 female holes.with both sides disconnected, I ohm out each hole of the 4 holes one at a time checking for connectivity on the ohm meter with each of the five holes on control box end of the wire. Only 2 of the holes on both sides gave me an ohm reading of connectivity.
Is that normal? I Figured at least 4 would give me a reading, but no only 2


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## brad1000 (Feb 28, 2021)

Cncest said:


> I had a similar problem. Cncest 6040 spindle stopped running. Turned out it was a bad wire between control box and the spindle. The wire broke right at the flex point in the cable tray.


How did you determine that at first? Did you ohm it out? 

Did you just start pulling the wires out of the sheath?


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## Cncest (Apr 26, 2020)

I checked the cable with a ohm meter. Then cut open the wire covering till the broken wires were exposed.


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## TimPa (Jan 4, 2011)

Cncest is right on.

FWIW, when ohming out a wire, if ONE strand is still connected, the wire will ring out zero ohms, or continuity. but, it will not be able to carry the needed current for a motor. often times we will wiggle the wire as we watch the meter...


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## brad1000 (Feb 28, 2021)

Cncest said:


> I checked the cable with a ohm meter. Then cut open the wire covering till the broken wires were exposed.


If you don't mind me picking at your brain here a little....

As I mentioned in a reply to someone else, the connection side with control box has five female prongs and the spindle side has 4. I ohmed out and found connectivity with 3 of the 4 of the prongs to 3 of the 5 on other end. Shouldn't all 4 female prongs (from the spindle side being that there are 4 on that side) have connectivity with 4 of the 5 on box side connection? Or is it normal for only 3 to have connectivity?

Do I start ripping the chain casing apart to get wire out with that knowledge?

Now in case this is important to know, this is only a 110v spindle. The box apparently has an ability to handle a 220 (think it is like D005 setting or something like that) so maybe the wire has a reserve prong in case there was another "leg" or phase electric.
I say this in case my problem really is just a bad spindle, wiring could be fine. This is me just checking all the boxes.

I really do appreciate you helping.

P.S. if you need pics or whatever, let me know


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## brad1000 (Feb 28, 2021)

TimPa said:


> Cncest is right on.
> 
> FWIW, when ohming out a wire, if ONE strand is still connected, the wire will ring out zero ohms, or continuity. but, it will not be able to carry the needed current for a motor. often times we will wiggle the wire as we watch the meter...


On that note, if my spindle is only a 110v (which it is), would your scenario fit to where I hear the spindle "whining" with a slight tightening up feel when I try turning it by hand during the "whine" but the spindle never actually spins?

Now in case this is important, what I mean by tightening is this: when the spindle is not running and I'm not asking it to run, I can manually spin that spindle bit freely and I don't feel anything; but when I ask at the run and I hear the "whine" when I go to turn the drill bit, it kind of feels like turning a combination lock where you can feel each turn one number at a time.


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## BalloonEngineer (Mar 27, 2009)

brad1000 said:


> Shouldn't all 4 female prongs (from the spindle side being that there are 4 on that side) have connectivity with 4 of the 5 on box side connection? Or is it normal for only 3 to have connectivity?


Yes, for a 3 phase spindle, you should have 3 phases "hot" wires and one ground wire. It will operate with just the 3 "hot" wires, but the ground should also be connected (allows not using a magnet or clip when using a touch plate). The 5th pin on the VFD end is to terminate a drain wire from the shield. The cable should be a 4 conductor, shielded cable. You "ground" the shield (only on the VFD end) to reduce EMI.


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## brad1000 (Feb 28, 2021)

BalloonEngineer said:


> Yes, for a 3 phase spindle, you should have 3 phases "hot" wires and one ground wire. It will operate with just the 3 "hot" wires, but the ground should also be connected (allows not using a magnet or clip when using a touch plate). The 5th pin on the VFD end is to terminate a drain wire from the shield. The cable should be a 4 conductor, shielded cable. You "ground" the shield (only on the VFD end) to reduce EMI.


Ok. this spindle is a US version 110V. Does that change anything?


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## brad1000 (Feb 28, 2021)

TimPa said:


> Cncest is right on.
> 
> FWIW, when ohming out a wire, if ONE strand is still connected, the wire will ring out zero ohms, or continuity. but, it will not be able to carry the needed current for a motor.* often times we will wiggle the wire as we watch the meter...*


This is what I did, and it worked. Apparently there must be a break right in the connection at the spindle because I did as you suggested and it works now.
Thank you so much. I was getting ready to buy another spindle.
Now I just have to figure out how to remove the casing of the connector to get at wires (female pins)


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## Cncest (Apr 26, 2020)

The casing unscrews from the base to expose the connections.


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## brad1000 (Feb 28, 2021)

Cncest said:


> The casing unscrews from the base to expose the connections.


inside of the chrome fitting i mean.


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## erniehatt (Aug 19, 2020)

brad1000 said:


> Had and been using my cncest 6040 4 axis 1.5kw CNC for like 2 months, then out of nowhere when I go to use it from computer and start the spindle, it whines but doesn't spin. Yes I can turn the spindle manually while it is winding but will not spin even with that "help" (thinking maybe it was stuck but no)
> I reset the control bow, but to no avail. Tried turning the spindle on in both PC mode and manual mode with same result. I assume the spindle windings are bad but I wanted to ohm out the wiring from the spindle connection to the control box. This is where I need help (and if you think there is something else I am missing to cause this).
> There are 4 lead holes on spindle connection and 5 on the control box side. I put one probe in each hole of the control side (5 holes) and checked each of the 4 connections on spindle side. Only 2 of the 5 holes on control side gave a reading of connectivity with one (different one for each of the 2) of the 4 holes on spindle side.
> My guess would of been 4 of the connections on control side would of had their own connectivity reading with their own on spindle side. Maybe I am wrong, not sure.
> ...


I must say , you are lucky, mine did the same from the start, and never did work even after a VFD board change, after that the dealer failed to respond, probably the same one you had. I ended up buying a 2.2kw motor and Huantang VFD, no more problems.


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## TimPa (Jan 4, 2011)

there are tools called pin insertion and retraction tools to get the pins out for repair. repairing cables can be done, but you have to know how to do it. you may have to buy a new cable... 

where the two tabs (with holes) are sticking up is called a strain relief. this helps stabilize the wire so as the equipment moves, there is minimal stress on the wires/connections. i assume that you had just removed the rest of the parts there?? they need to be there or things break...


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## brad1000 (Feb 28, 2021)

TimPa said:


> there are tools called pin insertion and retraction tools to get the pins out for repair. repairing cables can be done, but you have to know how to do it. you may have to buy a new cable...
> 
> where the two tabs (with holes) are sticking up is called a strain relief. this helps stabilize the wire so as the equipment moves, there is minimal stress on the wires/connections. i assume that you had just removed the rest of the parts there?? they need to be there or things break...


Everything has been fastened down only thing disconnected has been that connection so I could ohm it out. Appreciate the help.

May need a new wire, but I have no idea where to find one for this machine. Can find any parts for it whatsoever


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## TimPa (Jan 4, 2011)

can you take a close up pic of the end of the cable, disconnected?


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## brad1000 (Feb 28, 2021)

TimPa said:


> can you take a close up pic of the end of the cable, disconnected?


My assumption based in what I wiggled is probably one of the solders came loose connected to one of those female pins inside that connector (one that connects to the spindle right above it, not the little one near bottom left that is in my fingers)


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## TimPa (Jan 4, 2011)

i'm not familiar with that type. i think the unlocking feature will be on the front, between the connector block and the locking collar. are there any numbers visible on the connector, male or female ends? may help.

the connections may just be crimped... and not soldered


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## Cncest (Apr 26, 2020)

You can check the soldered connections by unscrewing the casing collar. Remove the locking screw if any on the plug casing. then unscrew the base from the collar casing.


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## TimPa (Jan 4, 2011)

nice CNCest! great help for him!


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