[barchdesigns]

I'm replacing a Fanuc A06B-6044-H007 AC Spindle Drive in my 3 Axis Vertical CNC machine with a Delta VFD-E in my shop. I've been gathring information for the last year in preparation for this project and am surprised at how little information I could find.

I started this thread to help document how to replace an old Fanuc Spindle Drive with new VFD technology. Also, ask a few questions, and hopefully get some answers.

In this machine I bought last year, the Fanuc spindle drive goes into an alarm state after running it for about an hour. I would have to let it sit for a while and then power it back on and run it for another hour. While we could dive into why the Fanuc Drive was misbehaving or how to repair it, I would like the purpose of this thread to stay on topic of replacing Fanuc AC Spindle Drives with newer VFD technology drives.

All code that we used to do this is Open Source. I hope that it will help someone else or someone will take this code and make it better.

The main project Kicked off tonight.....All the communications have been figured out. We programmed an Ardiuno MEGA to mimic a Fanuc Spindle drive and plugged it into the Fanuc 6M controls. We wanted to see if we could talk back and forth to the Fanuc 6M Controls and make the control think it was still connected to a Fanuc Spindle Drive. That was the relatively easy part, and we overlooked how to set parameters on a VFD to run a motor. No one here has a good understanding of that.

At one point we had the drive running the spindle motor up to a pretty good speed. But it was challenging to find any settings for the VFD to make it run the motor up to speed. Most of the time (including where we are at now) the motor starts to spin but never gains RPM. You can hear the VFD changing pitch like it is trying to ramp the RPM up, but then it will either over torque or pull a very large number of Amps for longer than I am comfortable letting it draw that much power and not be changing RPM.

Is anyone familiar with the basic motor settings for a Fanuc Model 3 Motor? I have some of the basics covered, I know it is

Fanuc Model 3 Spindle Motor
200V
3.7kw/5.5kw (Continuous/30 minutes)
17Amps/22Amps (Continuous/30 minutes)
4 Pole
3 Phase
Insulation: Class F
RPM 1500/6000
Amb Temp 40 degrees C


We do'nt know how to set the Delta VFD-E Drive to accurately run the Fanuc AC Model 3 Motor. It seems to be having a really hard time getting it going. Here is what we have:
Delta VFD-E
Model# VFD055E23A
7.5HP/5.5kw
Three Phase 230V

We have the communications covered like FWD, REV, Zero Speed, etc, and are receiving and sending all the corect signals back and forth between the VFD and the Fanuc controls, but we need help tuning the motor using the Delta VFD.

[barchdesigns]

So after doing some digging I found out we overlooked some basic information for motor settings.

1) On the VFD, we had the Accel speed set too fast for the motor to spin up. We were having the VFD electronically spin up faster than the motor can physically accelerate so it just looked like it was stalled and is the reason for our problems.

2) Calculating the correct frequency for the motor is quite simple if you know the max RPM and number of poles:

frequency = (# of Poles * RPM) / 120

So from this we take f = (4 * 6000) / 120 because we know that 6,000 RPM is our max RPM and we have 4 poles. 6000*4/120 = 200Hz. So we calculated that our max frequency should be 200 to make the Fanuc Motor spin up to full speed. This formula holds thrue that if the RPM was 3,000 your frequency would be 100Hz.

I found that our Pulse Genrator feedback card was for the wrong Delta VFD drive (cards for the Delta VFD-E and Delta VFD-VE are NOT interchnageble). We have ordered the correct one but it's going to be a few weeks before it arrives. For now we will be able to control basic speed and direction, but tool changes won't happen until we get the new card in and get it programmed.

[barchdesigns]

Got lots of forward progress on this retrofit this past weekend. Just about finished up. I figure another day of testing before we can start cutting metal for real.

We decided to build a new interface with the Arduino because we had problems with wires bending and breaking off of the 50 pin Honda connector. So we built out two prototype boards. One is a complete screw breakout access to each of the 50 pins of the Honda connector CN1 and the other board we built is a complete screw breakout for the Arduino MEGA. This will allow us to use these prototype boards in testing and diagnosing the future Fanuc retrofits. We just connect jumper wires between the screw terminals and configure it however we want.

Taking it one step further we purchased 5 optoisolator boards (2 channels each) to separate the noise between Fanuc and Arduino. We placed these between the Fanuc 50 pin breakout board and the Arduino breakout board. We also used a 16 channel relay board that has built in optoisolators since we needed a total of 22 communication lines back and forth.

Here are a couple pictures where we are at. You can see the 50 Pin CN1 Honda connector from the Fanuc controller plugged into the lower board. Then you can see the green and white wires coming from our prototype boards and going to the new Delta VFD. It works great except for one little .....okay major.....point. We configured this setup to read in the 12 bit speed command from the Fanuc controller into the Arduino, then output an analog voltage 0-10V for the Delta drive using a DAC controlled by the Arduino. The problem with this is we can't optoisolate the DAC between Fanuc and Arduino so we get noise in the whole system whenever this line is hooked up. Most of the time it is fine but every 30 seconds or so we will get some kind of noise throwing our 0-10V signal off. To fix this we have purchased an RS485 communication board to hook up to the Arduino. The Delta can take speed commnads from eithr 0-10V, or by RS485 communications. The RS485 will be optoisolated eliminating the noise issue.

So for now, we are up and functioning (minus tool changes until the new feedback board comes for the Delta VFD) but with some noise in the lines. Once we get the RS485 board and the feedback board we should have this retrofit completed. It's definitely more involved than I thought it was going to be, but still not bad with some electronics knowledge behind you. It's saving us a ton of money and we are updating the machines to newer technology. Seems like a win win overall.

We are discussing the possibility of manufacturing some professional interface boards, not only for ourselves, but for anyone else out there who wants to update pieces of the old Fanuc controls to newer technology without having to create the circuit boards by hand to connect the two. I wonder if anyone else is interested in retrofitting like this.

[metall]

Replacing old Fanuc AC Spindle Drive with Delta VFD-E and Arduino
Can you help us?
Would you please send the wiring diagram?

[barchdesigns]

Here is a pdf containing everything we needed to connect to the Fanuc 6 controller and Fanuc A/C Spindle drive on a Pratt and Whitney Trimac V. Your machine may be different and I would suggest referring to your own machine's wiring diagram. This should help if you don't have your machine's wiring diagram. We are working on making the wiring and code for the Arduino an open source project that will be available soon. We designed some custom optoisolator boards and are waiting for them to arrive back from the manufacturer to clean up our wiring. We also need to wire in the RS485 board yet and then we will release what we did.

[metall]

It was a period of more than 3 months FANUC (A06B 6055 H106) Driver I'm trying to repairing, but it did not work.

Did you complete the Fanuc drive VFD change?
Metal cutting tool change and tried it?
I am very grateful for your help.

[barchdesigns]

We are still moving forward each month with the retrofit. I started installing the OptoIsolator boards my brother had made to help isolate the Machine signals from the Arduino inputs in a tidy clean connection system. This new board from NoopLabs.com acts as a direct interface between the Fanuc Control and the Arduino. The board has pull up resistors built in to each input, and it will work with a wide range of signal voltages. It's going to make for a pretty handy interface.

I measured the signal coming back from the spindle encoder and it looked odd. Instead of a square looking wave it was more V shaped. I need to hook it all back up to the original Fanuc AC drive and measure the signal then to find out if I am just doing something wrong while the new stuff is hooked up. I was sending it 5V as a pull up voltage. This is the nect area I need to dive into after the Opto boards are finished being installed.

Lastly we will be hooking up an RS485 communication between the new Delta Drive and the Arduino so that they can digitally communicate. Also going to change the 5V power block for the Arduino as I think it may be a source of interference.

[Lrapso]

Hello I have find very good information here
thanks a lot for share
I just bought an hitachi wj200_55lf driver to apply on a Fanuc AC spindle motor A06B_0754-B20103000 but using lynux cnc as a cnc
I hope to have it wired to made the firs try on january as soon I have some expiriences I will share
best regards from Costa Rica
Luis Rapso

[devin_decater]

I'm really glad I stumbled upon this thread, I have wondered if such a retrofit could be possible for these older machines that parts are getting prohibitively expensive and hard to find for. I recently acquired an older EGURO gang tool lathe that has a blown spindle driver, and was thinking this would be the right solution to get this nice hunk of iron making parts again. I'm hoping to control the motor with a VFD that has a single phase input as I don't have proper three phase available, and for that matter convert the whole machine to run on single phase.

The EGURO has a Fanuc 3T controller that appears to be in working order, so long as you don't ask it to turn on the spindle. I'm thinking of getting the VFD first, and seeing if I can run the machine by controlling the motor manually with the VFD first, and worry about communications between the two later.

Point being, I'm very interested to hear whether this project ended up in a reliable productive machine, and any advice as to the direction I should head with with my project would be greatly appreciated.

[barchdesigns]

I am glad there is interest from others on how to do this. Last weekend we made some more progress on the VFD retrofit. We are nearly finished and I believe about 2 more weekends attacking the problems and we will have a complete "drop in - direct replacement" for a Fanuc AC spindle drive. Here is what has happened since the last post:

I've determined that isolating the VFD Motor Output wires away from the data lines of the machine greatly helped reduce noise in the 12 bit speed signal from the Fanuc 6M system. I did a lot of searching around about interference after installing a Digital Drive and isolating power seems to be the main issue.

We purchased an RS485 interface board for the Arduino Mega. These were about 50 cents shipped, but I had to buy 5 of them. Just search eBay for "RS485 Arduino" and they will come up. The Delta Drive can be commanded from setting parameters through RS485, such as FWD, STOP, Frequency, etc... Once we got RS485 working we were able to remove the FWD, REV, and 0-10VDC Signal wires to the Drive. I've attached a picture showing the RS485 through a RJ45 connector (pins 4 and 5, blue, blue/white) hooked up to the delta drive. We now have the correct encoder card for this drive and were starting to work on encoder feedback as can be seen by the grey wires. The yellow Network cable is what is hooked up to the RS485 rectangle board.

The Delta Drive is commanded many different ways, but we chose ModBUS via RTU because it was all open source, hardware was available, and it was cheap and easy to implement. All the commands are listed in the Delta manual. We are able to command FWD, STOP, REV, and exact Frequency of the drive. Right now we are only sending commands to the Delta drive, but the Delta drive responds with confirmations, which we have yet to code in to read. We ran out of time to work on it further this weekend as we stumbled into an interesting encoder feedback issue.

All our code will be available via my GitHub here: https://github.com/BarchDesigns as soon as I figure out exactly how GitHub works

The "encoder" back from our Fanuc 3 Spindle Motor is actually a Pulse Generator which is basically a gear with a tooth sensor. The signal it outputs is something I've never seen before. I didn't quite get down to the level of the motor where it was exactly, but I found a picture shown here that is what I believe is inside. You can see the Waveform back from the Pulse Generator is an AC waveform going between 1.84V and 2.4V centered around 2.12V. It's also quite noisy. I have another Fanuc 6M system with all original working electronics and it is the same measured signal with our oscilloscope on both machines. Right now we are working on a circuit to take the Fanuc Pulse Genrator AC wave form and make a Square Wave 0-5VDC by utilizing a Schmitt Trigger and some other components. We think this will be easier than somehow hooking up a new Optical Rotary Encoder to the Motor Shaft...

That is where we stand now....designing that circuit and getting it manufactured. I've also shown an update of the overall prototype boards all hooked up until we figure this completely out.

The machine has been up and running for a while with the new Delta VFD driving the Spindle Motor...the only catch is I have to do manual tool changes until the retrofit is complete. All in all not so bad as the machine can stay alive and making money. I try not to rely on it yet though as I would like to run into retrofit problems before I have to keep it running. I do run it a few times a week though and it has been happy so far.

To-Do list until the retrofit is complete:
Install Passive Braking Resistors
Read back RS485 from Delta
Get Good Encoder Signal
Get Orientation Signal
Hook up Load Meter/RPM Meter
Write PLC For Tool Change

[devin_decater]

I'm sure you have already seen this, but just in case I found this site that may have some useful information relevant to this..

FANUC-PAGE-8

[Deano7/11]

How did this retrofit end up? I may have a need for it on a fanuc6ta lathe as the spindle drive is acting up.

[barchdesigns]

We had a chance to work on it again during the weekend. We designed a circuit to read in the A/C pulse generator sine wave and give us a square wave pulse output that we can feed into the Delta drive. We discovered that we need a dual voltage power supply for our op amps in the circuit. When operating it with only one power supply we had a hard time getting a high enough voltage on our square wave for the Delta drive to read it.

In the mean time I purchased a used Fanuc Spindle Drive Top board and installed it in the machine. The machine is back to fully operational so it buys me more time to figure out the retrofit. I purchased a dual +/-12VDC power supply and need to hook it up to the op amps. This is currently where we are at. You can see from the pictures we had quite a noisy original signal, but we were able to clean it up. I forgot to snap a picture of the square wave output as we were trying to get the voltage high enough. Hoping to have some time in the near future to test the dual power supply.

As an alternative, we are looking at installing some gear tooth sensors to give us the square wave we are looking for. We may end up doing this anyway as using a few gear tooth sensors on the spindle itself would give us true quadrature encoding as well as a Z index position (that we could use for tool changes) all at 5VDC. In the mean time I am getting a few of these sensors to put on my Bridgeport Mill Spindle to understand how they work and ultimately give me a LCD screen with my actual RPM readout using an Arduino for my Bridgeport.

Gear Tooth Sensor under $4 404 - File or directory not found.

[devin_decater]

Well I have finally sourced a VFD unit that should be able to run the spindle motor on my EGURO Gang Tool Lathe. In my research I should be able to run the 5.5KW motor on single phase with an 11KW VFD. I hooked the VFD I found to a junk 10HP motor I had laying in the shop to make sure it would run okay on single phase without letting the smoke out and it passed the test with flying colors. When I hook the VFD to the Fanuc motor though it's a different story. It will turn, but it sounds kind of like an engine that is missing on one cylinder. Just not smooth like one would expect an electric motor to run. I remember it running smoothly with the old analog Fanuc spindle drive, even through the rotary phase convertor, it would just overload quickly due to the extreme voltage imbalance on the lines.

So I am looking for the basic parameters to run this motor. Of course the motor plate has been completely destroyed by whatever coolant the previous owner was running in the machine.

What I figure so far is:

3 phase
4 pole
200 Volt
120 HZ base frequency
200 HZ Max frequency
??? Min frequency
I'm using 20 second acceleration and deceleration to hopefully keep the amps pulled to a minimum during startup and braking (Maybe this is where I am running into issues..?)

If any of this looks incorrect, please let me know!

By the way, the VFD unit I got is a Mitsubishi A500, it is able to communicate with RS485, so I am really excited about commanding it with the Fanuc control as you have achieved.. As it is only a Lathe, I will not need to worry about positioning the spindle like you need to for the ATC on a mill, so hopefully it will be a little "easier".. Of course at the moment I would be happy just to have a spindle that turns!

On another hand, I'm quite happy to say the servo drives do not mind running on single phase. I have the 170V from the step-down transformer going to only A and 1, 1 and 2 are jumper to fool the phase detection, and it runs okay. It will need to be tuned now though as the Z axis overshoots dramatically in rapid and I am hearing some servo whining that was not present when running on the RPC. Small potatoes in the big picture though!

In case you were wondering I really cannot justify getting a shop with 3 phase, I am getting such a great deal on the space I have now that I really just have to deal with it. It's just an extra little challenge i guess.

[barchdesigns]

Hi Devin, The only thing that looks weird to me is your base frequency. That should be 50 or 60hz from what worked on mine. Basically the motor will spin faster with a higher frequency and slower with a lower frequency. Frequency (in a simplified nutshell) is what changes the speed of the motor. Your minimum should be all the way down to almost 0. You want the minimum as least as slow or slower than what you need to spin for locating the spindle orientation. Motor RPM is calculated by taking the constant of 120xFrequency and then dividing by the number of poles. For instance in your example to calculate the max RPM:

120x200 = 24,000
24,000/4 poles = 6,000 RPM

FYI, Check out American Rotary for 3 phase converters. I have them in my shop where I only have single phase and they work great! Currently I have a 30HP slave motor running the 3rd phase for my machines. It's quite worth it in my opinion to have the actual 3 phase instead of trying to make things work from single phase. Plus if I move, the 3 phase converter is not permanent so I can take it with me.

Also FYI, I have learned that the Fanuc command can be 3 different hardware interface. you will need to check what your Fanuc sends out to the drive. It can be 0-10VDC analog, 12 bit BCD, or something else I can't remember.

[UglyAmerican]

Hi I read you arduino sketch and looked at your setup. I have some comments to add.

Maybe the reason you are not getting data back from the VFD is the way you wired the RE/DE pins on the MAX485 converters. That is data flow control by hardware. You might have it tied so that you are "only talkling to the VFD" but not "lilstening, as you do not untie the RE/DE pin.

Perhaps you should create a write to the VFD only when the data from the CNC changes, so always keeping an "image" of all your input pins and if one changes then write to the VFD and use the RE/DE to talk, and sson as you end transmision go back to listening.

Greetings from Mexico.

[barchdesigns]

Hi, Thanks for the suggestion. I'll look into that RS485 tip when we put the Delta drive back in.....which may be real soon again

The original problem with the Fanuc Spindle Drive is back.....Spindle Alarm "2" (Excessive speed deviation). Earlier this year when I replaced the spindle drive main board (Just the main PCB, not the big power caps and stuff under the board.) it seemed to fix the problem right up. It's been approximately 6 months of running the machine on average 4 hours a day but the problem is slowly but surely coming back. I can run it at max RPM (5,000) for an hour or so and then the load meter starts to jump around and eventually the drive faults out. As a quick recap, I can manually override the spindle RPM to 90% and it works for another 30 minutes or so and the when the load meter starts to jump around again, I drop the spindle to 80% and we are good for a while again. It's a repeating cycle slower and slower until I eventually have to shut the machine off and wait an hour or overnight.

What is the most likely scenario to cause this alarm? I am hoping someone with experience can point me in the right direction. I am leaning towards a problem with the speed feedback signal as it warms up. Has anyone run into this problem before? Is it a common problem? I can't seem to find much info on it.

Barch Designs
877-201-9771

[barchdesigns]

The Fanuc drive is now working better than it ever has. I obtained a copy of the service manual for my Fanuc AC Spindle Drive and followed the instructions on adjusting the Variable Resistors on the PCB of the drive. Also parameter 0133 (max spindle RPM) was at 5,000, which I changed to 6,000 since that is what this machine should be doing.

At one point I thought I would be changing the transistors inside the drive (which I found are readily available for about $40 each) and learned a lot more about this Fanuc drive. I feel I can keep it running until we complete the retrofit. The old drive won't last forever so having this new knowledge will come in handy when we put the Delta drive back in.

The old drive Accels/Decels much quieter and holds RPM solid now. It sounds much happier overall. I'm going to tune up the other CNC machine in the shop the same way since it has the same controls.

You can see in the pictures that the A/B channels of the Square wave that's generated from the motor's pulse generator were a little out of their rated 50% duty cycle (meaning mountains equally as wide as the valleys)

[FlyingTool]

Hi ! i was really impressed with your work so far and like others here, i too am in a similar situation:

I have a really rigid old mill from the 80s with fanuc OM that is not working anymore and i wish to use the machine with either my own arduino controller(WITHOUT grbl) or linuxCNC.
After reading your post i thought i can use the existing Fanuc spindle motor....here are its details:
-Fanuc MODEL 8P
-Type A06B-0725-B102
-3.7/5.5 KW 750/6000RPM
-200v 3 phase 4 Poles
My question is regarding the voltage, Delta only has 230v 3phase drives if i'm correct so is it alright to use it with this motor? what did you do ?

Waiting for your reply.
THANK YOU

[barchdesigns]

Hi Lrapso, Yes the Delta drive can drive any voltage motor. The 230V is just the input supply voltage, but the output is set to whatever you want it to be in the Delta Parameters of the drive. You can drive a 50V motor if you want, or a 165V motor, etc. I only suggest this route if you are willing to part with a few more thousand dollars and a lot of time. After doing all this work I found out how easy it is to repair the old Fanuc boards and I actually have abandoned the retrofit for now. I found out all my problems were due to lack of knowledge on how to keep the Fanuc boards tuned up with all their analog voltage adjustments. Someone started a website where you can find and download manuals for Fanuc. I was able to find the service manual for my Fanuc AC Spindle Drive and adjust the variable potentiometers using my oscilloscope. If you have those tools it really is quite easy to tune a drive up. And if your good with electronics it's actually quite simple to swap out the transistors in the drive as well. You can find them for sale in a lot of places and it seems you can find even more used drives pulled out of old machines every day. Fanuc used surplus supply keeps going up and prices keep coming down. Hope that helps. I'm hoping to start a wiki on the projects I've done in the shop to document it further. While I am going to stick with the Fanuc drives for now, there is a lot of knowledge I want to share about how to keep them running.

Also FYI, you have to buy the correct input voltage drive if you want to replace it. So if your shop runs on 440, then you need to buy a 440V input drive, but it can still drive a 230V motor.