Spindle synchronisation problem

[leomonti]

Hello,
I've just replaced on my cnc lathe, the old MK2/9 controller/old CNC USB software, with the MK3/4 and TNG software.
I spent an afternoon trying to synchronize the spindle for threading job. I am using an optical sensor, therefore, one pulse per revolution, which in the previous configuration, worked perfectly.
Now, when I load a gcode for threading (the same one that worked before) if I exceed the 150 rpm of the spindle, a window appears that says "synchronization failed", and in any case, even at 150 rpm the thread pitch is not respected.
I connected the optical sensor output to the IDX input of MK3/4. When I turn the spindle by hand, the LED on the video lights up in the corresponding input, so the pulse from sensor arrives to controller.
The TNG user manual never speaks about the optical or hall sensor, but only about the index signal coming from the encoder. I would like to understand if the synchronization function through an optical or magnetic sensor is still supported in TNG, or if I will be forced to install an encoder. I would be very disappointed.
I tried to change all possible values ??in the spindle / sync section, without result, so I have reset everything to default values, but I cannot work. Should I use another sensor input in the MK3 / 4?
Can someone - maybe the Planet Cnc boss - help me to find the solution or configuration of the software and hardware?
Thank you in advance.

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[PlanetCNC]

"Synchronization failed" message usually happens because needed speed is too high. Check if motor speed and motion speed is set correctly.

[leomonti]

Hi, 500-600 spindle rpm are too high? Until two days ago, with MK2/9 and old software I had no problem.
Tomorrow I'll check again the entire setting. In transcribing the parameters from Planet cnc old to TNG I might have something wrong. But I've already checked a thousand times.
however you don't tell me if the connections I mentioned are correct and if there are any settings to be made on the TNG software. The user manual does not say anything about the synchronization through the sensor index signal. Talk only about encoder.
If it can be more explanatory, I can post the G-code file, generated by F360 Cam with Planet post processor.

[PlanetCNC]

Old software did not check speed limits during synchronization.

Connection is probably fine. There is nothing special to it.

Relevant settings are:
"User Interface/Speed/Spindle/Spindle RPM" - use "From Index" to see measured speed from your index signal.
"Input/Output/Spindle/Synchronization/Spindle RPM" - use "From index" to calculate speed using index signal.
"Input/Output/Spindle/Synchronization/Sync Signal" - use "From index" to use index signal for synching.

You can always send your profile .zip file to me to check it.

[leomonti]

I made the last few attempts this morning. I also replaced the optical sensor, but nothing changes.
If I exceed 250 rpm on the spindle, the "Synchronisation failed" window appears.
What else should I check? How can I solve? I cannot do a M8x1.25 thread at this slow speed. Even if the inverter is vectorial, at that speed - with 1/10 mm deep pass on alu - the spindle motor has no torque and stops.
Below the G-code
In the afternoon I'will send the profile file.

%
(FILETT_8MM)
N10 G7
N11 G18
N12 G90
N13 G21
N14 G28 U0.
N15 G28 W0.

(FILETTATURA1)
N16 T1 M6
N18 G54
N19 G97 S600 M3
N20 G95
N21 G90 G0 X28. Z5.
N22 G0 Z6.25
N23 X7.875
N24 G33 Z-34.938 K1.25
N25 X8. Z-35. K1.768
N26 G0 X28.
N27 Z6.25
N28 X7.75
N29 G33 Z-34.875 K1.25
N30 X8. Z-35. K1.768
N31 G0 X28.
N32 Z6.25
N33 X7.625
N34 G33 Z-34.813 K1.25
N35 X8. Z-35. K1.768
N36 G0 X28.
N37 Z6.25
N38 X7.5
N39 G33 Z-34.75 K1.25
N40 X8. Z-35. K1.768
N41 G0 X28.
N42 Z6.25
N43 X7.375
N44 G33 Z-34.688 K1.25
N45 X8. Z-35. K1.768
N46 G0 X28.
N47 Z6.25
N48 X7.25
N49 G33 Z-34.625 K1.25
N50 X8. Z-35. K1.768
N51 G0 X28.
N52 Z6.25
N53 X7.125
N54 G33 Z-34.563 K1.25
N55 X8. Z-35. K1.768
N56 G0 X28.
N57 Z6.25
N58 X7.
N59 G33 Z-34.5 K1.25
N60 X8. Z-35. K1.768
N61 G0 X28.
N62 Z6.25
N63 X6.875
N64 G33 Z-34.438 K1.25
N65 X8. Z-35. K1.768
N66 G0 X28.
N67 Z6.25
N68 X6.75
N69 G33 Z-34.375 K1.25
N70 X8. Z-35. K1.768
N71 G0 X28.
N72 Z5.

N73 M5
N74 G28 U0.
N75 G28 W0.
N76 M30
%

[PlanetCNC]

If you want me to check this I need your profile .zip file.
Use File/Export profile to export it. You can send it to our support email.

[leomonti]

In the afternoon I'll do it.
Thak you.

[leomonti]

Hi,
I sent my profile.zip to your helpdesk mail.

[PlanetCNC]

G33 with K1.768 at 250 RPM requires axis speed to be 530.4.
Your axis speeds are limited to 500 and 300. You need to increase your speed limits.

[leomonti]

Ops. I had not calculated that.
Thank you!
Tomorrow I'll try and I let you know.

[leomonti]

Hello,
Now works!!
I am still not fully satisfied with the reading from the optical sensor which, at times, seems erratic and fluctuating. I do not know if it is the type of sensor that I am using and of which I am attaching the photo. It's a 5v sensor. The disk diameter is 80 mm. and open window is round 10°.
Could a Hall sensor be better or I must step directly to the 100 PPR encoder?

There is another thing that I don't understand so well: if I use the setting "Input / Output / Spindle / Synchronization / Spindle RPM" - "From index" the Z axis has some speed oscillations that go together with those of the spindle.
But if I wanted to use "As set", the Z axis would still have to follow the spindle through the signal from the index, right? Instead, in this case, the Z axis travels at the speed calculated by the Cam based on the set revolutions, and not on the real ones. Let me explain: if I have S500 on the G-code file, but, in reality, the spindle is turning 485 rpm, shouldn't the Z axis still follow the revs detected together with any oscillations? If at the M3S600 command, the output card - which does not have a perfectly linear curve - sends to the inverter a voltage with which the latter commands the motor at 480 rpm, even if I have set "Input / Output / Spindle / Synchronization / Spindle RPM "- As Set, shouldn't I get sync anyway?

[PlanetCNC]

Erratic behavior is probably due to noise. I always use optocoupler to connect inputs to controller.

Encoder is not needed if your spindle speed is constant. But you can not do rigid tapping or any other stuff where spindle speed changes.

If you use "As Set" then you don't use measured speed but set speed (with K of F). You need to use "From Index" if you want to sync to 485 and not to 500 as set in g-code. In other words "As Set" does not sync to actual speed.

In my opinion you should do something about noise. There should be no fluctuations and your speed should be constant.

[leomonti]

Thank you. I'll attempt to reduce noise.
The speed variation during the spindle rotation, is 0.1 Hz on the inverter display. But reading the TNG screen, the speed measured by opto sensor is round 10-30 rpm.
Do you suggest to connect the sensor output to idx input with an optocoupler? I can try, I've some optocoupler boards in my boxes.
Using a 0-10V output board is virtually impossible to have the exact speed as set in G-code. The output voltage of the board, or the 0-10V input on the inverter, have not a linear response curve in a range between 150-2800 rpm. If I trim the out voltage to have exactly 1000 rpm when the g-code is S1000, i can't have 400 rpm when g-code is S400 or 2000/2000. I've for example, 420 or 1970, or similar difference at different speed steps.

[leomonti]

Thank you. I'll attempt to reduce noise.
The speed variation during the spindle rotation, is 0.1 Hz on the inverter display. But reading the TNG screen, the speed measured by opto sensor is round 10-30 rpm.
Do you suggest to connect the sensor output to idx input with an optocoupler? I can try, I've some optocoupler boards in my boxes.
Using a 0-10V output board is virtually impossible to have the exact speed as set in G-code. The output voltage of the board, or the 0-10V input on the inverter, have not a linear response curve in a range between 150-2800 rpm. If I trim the out voltage to have exactly 1000 rpm when the g-code is S1000, i can't have 400 rpm when g-code is S400 or 2000/2000. I've for example, 420 or 1970, or similar difference at different speed steps.

[PlanetCNC]

With analog control (0-10V9 is impossible to have precise control. That is why feedback via sensor or encoder is needed). But usually is works fine, assuming you don't have noise in signal.

[leomonti]

SOLVED!!
I've replaced the optical sensor with an Omron high-speed inductiv proximity switch connected via optocoupler.
Now works perfectly, without erratic behavior.
Probably, the problem was not the optical sensor but the connection without optocoupler. I've decided to use the proximity, even because the optical sensor is 5 V signal output/power, and my optocoupler board needs 12V signal/power. In anyway, I guess that the proximity is faster and more consinstent than the cheap optical sensor posted above.
Thank you to Planet for support!

[Shoboolan]

Can you tell me what model of Omron high-speed you are using? Thank you.

[leomonti]

Sorry for long time in reply.
Here the picts of Omron label