Pm-940m-cnc (pre-assembled)

[Sal_the_man]

Awesome, thanks a bunch Dave. Going to dig through them now

 

[Sal_the_man]

Our wiring is different and looks like I do not have the two other wires exiting from the top of my VFD as marked with the blue streaks.

I'm going to look at your wiring diagram and compare it to mine. This is odd.

Our spindle works, but the RPM setting is nowhere near what I physically measure with my naked eye (and a paint mark). In addition, we are still getting a reading of zero RPM in both screenshots even though the spindle is operating and spins higher/slower according to my setting.

 

[Sal_the_man]

In addition, our software settings are nearly identical with exception to the angular headstock motor which we seem to have removed from the machine.

 

[B2]

Our wiring is different and looks like I do not have the two other wires exiting from the top of my VFD as marked with the blue streaks.

I'm going to look at your wiring diagram and compare it to mine. This is odd.

Our spindle works, but the RPM setting is nowhere near what I physically measure with my naked eye (and a paint mark). In addition, we are still getting a reading of zero RPM in both screenshots even though the spindle is operating and spins higher/slower according to my setting.

Hi Sal,

Glad to hear you got my photos. It did take me a while to capture them so that you could read them. I do not regret doing this as it provides a record for me if my system ever stops working! In fact, I am reviewing/learning quite about a bit about my machine in trying to help you out.

I think I see part of your issue in the photo of the spindle speed. The spindle speed is limited by the VFD max Hz out limit, which if I recall maybe about 400Hz. The gearing of the Mill then determines the max RPM of the spindle. There are two mechanical settings, one for up to 980 RPM and the other for upto 3200 RMP. The Mach3 software puts out a digital number to the nMotion based upon the RPM you put in. But, this is just a maximum binary number. The nMotion then used this to output a DC voltage to the VFD,where the maximum binary number corresponds to 10 Volts DC to the VFD. The max voltage the VFD wants to see is 10 V DC and it then generates 400Hz sine waves to the motor. Sure in Mach3, you select an RPM, which is artificial as one can only get a max frequency out of the VFD. Meanwhile one can setup the Mach3 software to readout any RMP value based upon the pulley configuration you tell Mach3 the Mill is using! We do not have pulleys, but we do have gears. Under the configuration tab pull down there is a place for pulley selection. In mine, under pulley1 there is a max reading of 1000 RPM and when this is put into the setting then on the Spindle speed screen the max you can type in is 1000. Your software most likely has 1500 as the setting under pulley1. I think you can make this any number you want, but when you spin up the spindle the VFD can only put out 400Hz. If you want to go faster than this then you must switch the gear setting from the 0-980 to the the 3200 out put and the gear ratio makes the max speed now close to 3200. The VFD is still only able to put out a 400Hz wave, so the motor is running at the same max speed. My motor label actually indicates that the max frequency it is wanting to see is 200Hz. So either, it is being pushed to a much higher RPM or the VFD is set to only put out a max of 200Hz for 10VDC input. The motor label also says the motor will go up to 1390 rpm, but who knows that the gear ratio is between the motor and the spindle.
Remember, we have no feed back to Mach3 so it has no idea what speed the spindle is turning, if it is turning at all! Hence, the RPM reading on the Mach3 window is unknown and listed at zero. It is possible that there is a wiring problem, but my guess is that this is all software, and is almost irrelevant to actual operation. So, I tried some more experiments. I changed the pulley setting for pulley1 to 1500 rather than 1000 and sure enough, the Mach3 spindle speed window says the spindle is turning at 1500, but it is really only going the max of the VFD output frequency (~400Hz ?) to yield a spindle speed of about 1000RPM. I also pulled up the motor turning configuration and looked at the spindle settings. They do not change when one changes the pulley setting nor do they change for different spindle speeds selected. After putting the pulley setting back to 1000, I ran a couple of other situations. Setting the spindle speed to zero, the spindle will still turn very slowly. I estimate about 1 turn per 1.5 second. When I set the spindle speed to 20 RPM then I estimated the spindle to turn about 1 revolution each second, which would be 60 RPM, not 20! This can be somewhat estimated via observation. This low value is not unexpected as the DC control voltage (I did not measure it, but should) going from the nMotion to the VFD is probably not very accurate near the end of the scale of the nMotion digital to analog converter. I would not expect yours to necessarily behave the same. I then set the spindle speed to 200 RPM and sure enough it was going a lot faster. I then pushed on the spindle over speed (S-ov) up(+) button and the speed increased accordingly (You can even hear the machine noise pitch increase). However, when set to 1000 rpm, this button has no effect as the max speed has been reached.

Through out all of this the Mach3 RPM reading is always zero, just as in your photo and mine. This is probably because this reading box is only used if there is a tachometer on the spindle providing the feedback for an actual measurement!

So maybe there is some other setting in your Mach3 that is yielding a incorrect spindle speed. I think I have sent you most of my setting photos, but maybe there is a pinout that is connected differently???

Just in case something else is wrong with the wiring I took more pictures of the wiring and will include them.

WRT to the two "sets" of wires connected at the top of the VFD: They have the same labels R1 and S1 (new picture provided) as the back wires. The smaller diameter set of wires go "directly" to the spindle motor FAN, so as long as the motor is being cooled sufficently, I don't think these would be your issue. So, on my machine this is wired DIFFERENTLY from the ckt drawing in my owner's manual, pdf page#13 (and labels table pdf p12), where it shows the fan motor to be M4 and in the ckt drawing it show M4 to connected via breaker FU2 and relay KM1. This is not the case, the fan is simply connected to the input (top) the VFD via R1 and S1! By the way, just in case my spindle motor is different I will send photos of the motor label and its wiring connections. One picture is for the fan, M4, connection at the top, and the other is to power the spindle motor, M1, the third is of the motor label and motor. The other (larger diameter) set of R1 and S1 at the top of the VFD appear to come from the QM breaker. It is interesting in the drawing p13 that the wires from QM to VFD have dots on them. This usually means that their is a connection, but they do not show anything extra being connected here. Anyway, as soon as the main power is turned on, before hitting the Green ON button on the control arm box, my spindle motor FAN starts running. The Spindle does not come on without turning it on with Mach3, which which requires both the software RESET button must be touched/on and the spindle on/off software button that indicates the VFD is being controlled by the software spindle on/off button.

So to reiterate, if the other parts of the drawings, and my my look-see, are correct, the main power comes into a set of terminals at the bottom of my big electronics box and the output via these adjacent terminals which are labeled L and N (not L1 and N1 as shown in the manual) as well as the green-yellow (Neutral) and then the L and N go to the main power switch on the side of the electronics cabinet while the green-yellow wire goes to a bunch of screw terminals for distribution. { By the way these two, L and N, are the two sides of the 220 volts and the N is NOT the neutral of my home breaker box. I also ran a separate, 4th wire, ground wire to the mill.} The output wires of my main power switch are labeled L2 and N2 and these distributed as shown at the top of the manual pdf page 13. In particular they go to QM and become R1, S1 which feed the top of the VFD (and as mentioned my spindle motor fan!) Indeed as the drawing shows for QM there is a wire the connects the top to the bottom and has no label numbers on it. This QM seems overly complex, but maybe this is an option for folks who have a three phase power or something. There do appear to be mechanical programing switches on QM.

Lastly, I think I mentioned it before, but some time ago, I used a strobe light to measure the actual spindle speed. I do not recall exactly, but over most of the middle to upper spindle speed range the reading in Mach3 where I set the speed, was fairly close to the measured RPM,.... only about 5% -10% off.

Best,
Dave

 

[B2]

Hi Sal,

So I quickly measured the input pin voltage at the VFD as a function of the Mach3 spindle RPM setting. The voltage between the VFD pins at wires 079 (ACM) and 081 (AVI) (see my earlier photo of the bottom of the VFD) varied reasonably linearly with Mach3 RPM setting. For each 100 RPM increase in Mach3 the voltage at the VFD went up by 1 volt DC. At 0 RPM it read .3VDC, 100 RPM it was 1.1VDC, 200 RPM yielded 2.0VDC, 300 RPM yielded 3.0, 500RPM yielded 5.0VDC, ... , 900 RPM yielded 8.9VDC, 1000 RPM yielded 9.9VDC.

Dave

 

[phazertwo]

Sounds like you need to adjust the max frequency in the VFD.

PZ

 

[B2]

Hi Sal,
I woke up this morning thinking about your situation with the spindle speed. I guess I may not fully understand all of your description of the spindle speed issue.

You said: "Our spindle works, but the RPM setting is nowhere near what I physically measure with my naked eye (and a paint mark). In addition, we are still getting a reading of zero RPM in both screenshots even though the spindle is operating and spins higher/slower according to my setting."

Fixing the pulleys configuration setting to 1000 rather than 1500 should have help to remove some confusion, but should not change the maximum speed of the spindle. Then setting the Mach3 Spindle Speed RPM to 1000 simply means that the actual spindle RPM is 100% of the VFD max setting. Likewise, Mach3 Spindle Speed RPM at 500 would mean the spindle RPM is 50% of the VFD max setting. Phazor2 maybe correct that the VFD internally maybe off, but I would not mess with it until you have exhausted the other possibilities. (I have not read about how to adjust this yet.) (By the way, if there truly is something wrong with your VFD component I think that PM warranties the parts for 3 years.?)

Also, from your comment above and the screenshots we learned that. 1) zero RPM is always the case in Mach3 as there is no tachometer feedback and so there is nothing to be displayed in this box 2) "Spins higher/slower according to my settings" I assumed this means that you are typing in a number in to the small button box "Spindle Speed" of the Spindle Speed window and hitting enter to make it change. At which point the spindle responds to the new speed. If this is the case, then it seems to me a digital code is being sent to the nMotion and then a DC signal must being generated by the nMotion and sent to the VFD pins via the input wires 079 (ACM) and 081 (AVI). Hence, that is working. So that leaves: 3) "RPM setting is nowhere near what I physically measure" This has no quantitative info except that you say that "the spindle spins higher/slower ....... as it should." This makes me think that all is working but that you just have no real way to measure the physical speed.

Short of you buying/borrowing a simple strobe type tachometer there is not a lot you can do to ensure that the speed is calibrated/functioning properly.

I used the following g-code to watch my spindle speed increment up from min to max." Maybe you want to try it?

(In Mach3, the General Logic configuration check the box for G04 setting to Dwell in millisec.)
(Spindle to turns on at 60 rpm, then wait 10 seconds, then increase the spindle to 200, wait 10 sec., etc.)

M3 (spindle on)
S 60 (spindle speed 60 rpm, one revol per second)
G4 P10000 (dwell 10000 milli seconds, 10 seconds)
S 100 (spindle speed 100 rpm)
G4 P10000 (dwell 10000 milli seconds, 10 seconds)
S 200 (spindle speed 200 rpm)
G4 P10000
S 300
G4 P10000
S 400
G4 P10000
S 500
G4 P10000
S 600
G4 P10000
S 700
G4 P10000
S 800
G4 P10000
S 900
G4 P10000
S 1000
G4 P10000
S 0
M5

This turns on the spindle, sets the speed to 60 rpm, then dwells at his speed for 10,000 milli seconds, then increments the speed up, dwells, etc etc etc. If this code will not run for you then you might have to change the G4 setting in the General Configuration check boxes. G4 P10000 is suppose to mean "Dwell for 10,000 milliseconds" where the P means milliseconds and is suppose to be independent of the machine configuration, but I found that I needed to check the configuration box for G4 indicating milliseconds. I think this maybe because the G4 command is non-modal and is usually combined in the same line with another G code.

I ran this program and recorded the spindle motion for you. Maybe this will give you a better feel for speeds.

Dave

 

[Sal_the_man]

Thanks @B2.

Going to give your suggestions a shot today.

Sorry for the delay. @chocadile and I have been booked with work recently.

 

[Sal_the_man]

Hi Sal,
I woke up this morning thinking about your situation with the spindle speed. I guess I may not fully understand all of your description of the spindle speed issue.

You said: "Our spindle works, but the RPM setting is nowhere near what I physically measure with my naked eye (and a paint mark). In addition, we are still getting a reading of zero RPM in both screenshots even though the spindle is operating and spins higher/slower according to my setting."

Fixing the pulleys configuration setting to 1000 rather than 1500 should have help to remove some confusion, but should not change the maximum speed of the spindle. Then setting the Mach3 Spindle Speed RPM to 1000 simply means that the actual spindle RPM is 100% of the VFD max setting. Likewise, Mach3 Spindle Speed RPM at 500 would mean the spindle RPM is 50% of the VFD max setting. Phazor2 maybe correct that the VFD internally maybe off, but I would not mess with it until you have exhausted the other possibilities. (I have not read about how to adjust this yet.) (By the way, if there truly is something wrong with your VFD component I think that PM warranties the parts for 3 years.?)

Also, from your comment above and the screenshots we learned that. 1) zero RPM is always the case in Mach3 as there is no tachometer feedback and so there is nothing to be displayed in this box 2) "Spins higher/slower according to my settings" I assumed this means that you are typing in a number in to the small button box "Spindle Speed" of the Spindle Speed window and hitting enter to make it change. At which point the spindle responds to the new speed. If this is the case, then it seems to me a digital code is being sent to the nMotion and then a DC signal must being generated by the nMotion and sent to the VFD pins via the input wires 079 (ACM) and 081 (AVI). Hence, that is working. So that leaves: 3) "RPM setting is nowhere near what I physically measure" This has no quantitative info except that you say that "the spindle spins higher/slower ....... as it should." This makes me think that all is working but that you just have no real way to measure the physical speed.

Short of you buying/borrowing a simple strobe type tachometer there is not a lot you can do to ensure that the speed is calibrated/functioning properly.

I used the following g-code to watch my spindle speed increment up from min to max." Maybe you want to try it?

(In Mach3, the General Logic configuration check the box for G04 setting to Dwell in millisec.)
(Spindle to turns on at 60 rpm, then wait 10 seconds, then increase the spindle to 200, wait 10 sec., etc.)

M3 (spindle on)
S 60 (spindle speed 60 rpm, one revol per second)
G4 P10000 (dwell 10000 milli seconds, 10 seconds)
S 100 (spindle speed 100 rpm)
G4 P10000 (dwell 10000 milli seconds, 10 seconds)
S 200 (spindle speed 200 rpm)
G4 P10000
S 300
G4 P10000
S 400
G4 P10000
S 500
G4 P10000
S 600
G4 P10000
S 700
G4 P10000
S 800
G4 P10000
S 900
G4 P10000
S 1000
G4 P10000
S 0
M5

This turns on the spindle, sets the speed to 60 rpm, then dwells at his speed for 10,000 milli seconds, then increments the speed up, dwells, etc etc etc. If this code will not run for you then you might have to change the G4 setting in the General Configuration check boxes. G4 P10000 is suppose to mean "Dwell for 10,000 milliseconds" where the P means milliseconds and is suppose to be independent of the machine configuration, but I found that I needed to check the configuration box for G4 indicating milliseconds. I think this maybe because the G4 command is non-modal and is usually combined in the same line with another G code.

I ran this program and recorded the spindle motion for you. Maybe this will give you a better feel for speeds.

Dave

Just ran your program for pulley 1. Going to give this a short for pulley 2 now!

In the video I mentioned yours is a bit faster but our spindle speed does seem similar upon review. Let me know your thoughts though.

 

[Sal_the_man]

Second test @B2