Hi, Does anyone know where to get a 3kw water cooled spindle in australia, the bearings are going in mine and its only 6 months old, so need something quickly to replace it while I get it fixed,
Thanks
Hi, Does anyone know where to get a 3kw water cooled spindle in australia, the bearings are going in mine and its only 6 months old, so need something quickly to replace it while I get it fixed,
Thanks
How on earth did you manage to go through the bearings in 6 months ? ? ?
Cheers
Roger
I have no idea, from what I understand its a 4 bearing model with italian bearings, but it screams constantly when its on, just in last couple days, I have been cutting a lot of acrylic but I wouldnt say excessive cutting as I am only really running it 3-4 times a week.
Its a 3kw gdz100-3B water cooled spindle, chinese jobby.
Um - arcing across the bearing balls from the VFD? Yeah, weird, but that could do it.
Have to strip it down and inspect the bearing. A carbon brush on the shaft for earthing might be needed.
If you could identify the bearings and buy in replacements, you should be able to swap them over in one day. That might be as fast as anything else.
Cheers
Roger
Thanks for the replies guys, the manufacturer is sending me out the bearings to replace, I also ordered a second spindle from them, so I can reduce the down time on the machine, basically swap it out while I fix the other one, then atleast I will have a spare if something happens again, is there a way I can test if my spidle is arcing out from my VFD?
Thanks
Lyndon
the manufacturer is sending me out the bearings to replace
OK, this manufacturer is worth knowing about. Very different from so many Chinese eBay distributors, who know nothing.
Yes, you can check the spindle yourself. Simply put an AC voltmeter from the shaft to your 0V point - like maybe the frame. Just press a bit of wire against the spinning shaft (somewhere smooth!): any contact will do. If there is more than (say) 0.5 VAC, then there could be arcing through the bearings. This is a problem.
Now, if there is a problem there, a simple carbon brush pressed against the shaft anywhere and connected to gnd/0V should help immensely. The arrangement needs to PRESS the brush against the shaft, but not all that heard. A kluge would suffice
Of course, if the brush erodes away quickly or you end up with a big arc-mark around the shaft, then something is seriously wrong with the motor/spindle!
Cheers
Roger
It is very normal to have rotor voltage more so when using a VFD Drive, there is nothing that is seriously wrong with the motor / spindle if it has a shaft voltage
You can't use a standard meter to measure the shaft voltage it will give you a false reading or no reading at all
Mactec54
@mactec
No, I was not suggesting using a common voltmeter to measure the voltage, just to detect whether or not there seems to be a small or large voltage. Measuring requires a knowledge of the waveform AND how the meter converts the incoming AC voltage to DC. That is not needed here.
Despite that, my thanks to you for the PDF. It was extremely educational. Clearly there is much to learn about the differences between a cheap commercial unit and a nice theoretical version of a 3-phase VFD. I was assuming that mfrs would filter their waveforms into clean balanced sine waves: silly me. (Me, I use industrial brushed DC motors and have none of the problems.)
Just as a niggle, I strongly dispute Marathon's claim that there is any large difference between their conductive brush ring and a common carbon brush, but one must allow for the spin (or ignorance) of their marketing dept. The bit about maintenance of carbon brushes should be weighed against the fact that cars will often go for hundreds of thousands of miles without a change of brushes on their alternators (assuming they have them).
Cheers, and thanks
Roger
The VFD output PWM is nothing like a sine wave may be you can tell them how to fix this 60 year old problem
It's not Marathon's conductive brush, it what is used throughout the industry and is superior to any kind of carbon brush will ever be, there is zero maintenance and 360 degree contact with this conductive brush design and is used by all the major AC motor manufactures they add them inside the motors in the manufacturing process, the outside brush is an option for those that don't have them, alternators have brush problems, go to an auto parts store and ask them how many alternators or repair kits they sell a week
Mactec54
Thanks for the info, tho somewhat over my head, but I will find someone to check it out based on your input, I bought the machine direct from the manufacturer in china and not thru ebay, they gave me a 1.5yr warranty. having said that they wouldn't replace the motor until it actually blows or seizes effectively, but I did manage to get the bearings from them. My entire machine runs on single phase 220v. It uses a fuling inverter and has a single phase emi filter, pics attached.
Thanks
Lyndon
The filter helps the Main input Power supply it would need an output reactor between the spindle and VFD to have a small affect on the Spindle Rotor Voltage, but this causes a loss in performance, no amount of Filter protection can prevent Rotor voltage completely, How ever that's what ceramic Bearings are mostly used for
What size is your spindle motor as that filter looks to be under rated @ 20A
Mactec54
Its a gdz100-3B 100mm, 3kw, 12A, 400Hz water cooled spindle,
is it possible to get ceramic bearings for this spindle?
I am having a hell of a time tying to find someone that will even look at my cnc for servicing or repairs, they all mainly do the big expensive machines, I guess there is not enuf $ servicing these basic ones in comparison, here in Adelaide, so it looks like I am going to have to do everything myself
Sure you can get the Ceramic Bearings from the some source as the replacement Bearings they are sending you, to change the Spindle Bearings you will need the correct wrenches for the nuts on the spindle to take it apart, if you damage any of the parts they will be rendered junk as this will affect the balance of your spindle
So the Filter should of been 30A and EMI Rated Using single Phase you have around double the spindle rated Amps at the VFD input
Mactec54
Thanks mactec54, I have ordered a 30A EMI filter and finally found someone that will change the bearings and test for high rotor voltage on the spindle, your input and RCaffins is very much appreciated, I have noticed you 2 put in a lot of support here @ cnczone, a BIG Thumbs UP and thank you to you guys.
Lyndon
I think you did a right decision to get another new spindle not only a bearing.The warranty of bearing on some china water cooling spinlde is only 6 month(provided from bearing manufacturers),which may includes yours-------3kw water cooling spindle,stepper motor,4 zones vacuum table,Ncstudio control system?
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I think you did a right decision to get another new spindle not only a bearing.The warranty of bearing on some china water cooling spinlde is only 6 month(provided from bearing manufacturers),which may includes yours-------3kw water cooling spindle,stepper motor,4 zones vacuum table,Ncstudio control system?
You can get them from CNC3D.
https://www.cnc3d.com.au/product-pag...e-spindle-er20