Hi Sir

We have another retrofitted Machine, today we saw that Spindle RPM reading is not stable, at 100 rpm screen show 90 t0110rpm, at 500rpm hmi show 440 t0 520, also increase error with respect to rpm.     

            https://www.youtube.com/shorts/Esl7l-lv8JQ

    2nd issue is that machine stop after 5 to 10 min Spindle running and alarms in picture

  the  parameters are 

   32000 = 0.5

   30200 = 2 

   35400 = 25

   35410 =16

   35430 = 0

   35440 = 1

   35450 = 0.5

   35510 = 0

How I can Set these problems.

With regards

Rana Shafay

If sensor is OK (hope you have checked it) it seems that you have non-damping process in speed controller. 

You can observe waveform of actual axis velocity ($VA_VACTM[ax] variable) by means of standart trace function. If it appears that process is non-damping try to decrease value of proportional gain of speed controller.

Also you can use servo autotune function, seems it is standart function on 840D sl, to adjust PI controller coefficients.

Hi Sir 

 Thanks a lot of your quick response 

what is mean of Sensor please explain you mean External encoder.

and how much i increase or decrease the P and I values.

If sensor is OK (hope you have checked it) it seems that you have non-damping process in speed controller.

You can observe waveform of actual axis velocity ($VA_VACTM[ax] variable) by means of standart trace function. If it appears that process is non-damping try to decrease value of proportional gain of speed controller.

Also you can use servo autotune function, seems it is standart function on 840D sl, to adjust PI controller coefficients.

with regard

Rabna Shafay

M. Shafay

Hi Sir 

 Thanks a lot of your quick response 

what is mean of Sensor please explain you mean External encoder.

 Yes, I have meant external encoder

M. Shafay

and how much i increase or decrease the P and I value

If process is non damping you should decrease Kp factor, increasing of Integral time constant just enlarge period of oscillation.

HI Boss

 Spindle RPM is same as command but reading are change (Variation).Which is parameter i chang the value

 K and T

With regard

Rana Shafay

M. Shafay

Spindle RPM is same as command but reading are change (Variation).Which is parameter i chang the value

Sorry, but I don't understand your last post.

I think that speed of rotation is really floating.

Try to decrease Kp factor of speed regulator (p1460 in spindle drive parameters) by 30% from actual value. Integral time constant (p1462) affects static error of regulator. Usually you  shouldn't  change it (basically this value is in range of 2.0-10.0 ms).

Try to use auto servo tune function.

For better understanding of how changing of PID coefficients affects on quality of transition process look on the attached gif.

Little remark. Sinamics drive doesn't use derivative gain, I think for better noise immunity. Because derivative gain is very sensible to noise.

Hi Boss CNCNIK

Bundle of thanks Sir that you have give me valuable time and advise.

I think that speed of rotation is really floating.

Try to decrease Kp factor of speed regulator (p1460 in spindle drive parameters) by 30% from actual value. Integral time constant (p1462) affects static error of regulator. Usually you  shouldn't  change it (basically this value is in range of 2.0-10.0 ms).

Try to use auto servo tune function.

For better understanding of how changing of PID coefficients affects on quality of transition process look on the attached gif.

Little remark. Sinamics drive doesn't use derivative gain, I think for better noise immunity. Because derivative gain is very sensible to noise.

I changed these parameters but after running of 5 to 7 minute machine stop.

Now during spindle running at 50rpm to 1500rpm, observed that C axis reading also running ( Continues move).

but another machine behavior are not same . If sample Spindle move that C-axis reading is not changed,

Rana Shafay

, 

Hi Sir 

  thanks a lot for your guideline.

What do you mean by Spindle RPM is same as per command?

Did you measure actual spindle RPM externally by digital tachometer?

From the information you shared so far, I understood that, main spindle & C axis are same & both have RPM fluctuation problem. If my assumption is same, it is external encoder signal or cable or coupling or SMC problem. Please switch over on motor encoder & check spindle performance. If speed founds steady, you need to change external encoder or SMC if connected in line with external encoder.

Hope this helps.

 I mean that in Jog or Mode spindle run at 100rpm and direction, Spindle rotate exactly at 100 rpm, measured through Tachometer, RPM are 100 (ok) but HMI reading is fluctuate 89 to 109. At different speed of Spindle , Spindle reading fluctuation  increased.

 2nd point is that c-axis is good in movement and reading is same of C-axis according prog (if call 45* ,  C-axis move 45* and Physically position of c-axis is correct. 

 But 

 when we run only spindle (S100 M03) without c-axis in JOG or MDI mode , we checked with spindle reading ,c-axis reading also move ( Change) till spindle run. after 5 to 7 min running of spindle machine stop due to alarms. pic is\ attached

 like this behavior of machine we see 1st time. 

  after change some parameters 35150 etc  25000 alarm generate

 with regard 

 Rana Shafay

Hi Sir

I thankful to you for very good response.

unknown user

Please check your motor encoder, encoder cable, its shielding, connection etc. etc. This problem is related with motor encoder EMC.

Hope this helps.

Sir are you sure that Motor and cable etc issue.

Sir I have a question here that why C-Axis reading move with spindle. PLEASE SEE THE VEDO OF SPINDLE AND  C-AXIS SCREEN 

WhatsApp Video 2022 09 26 at 9 30 50 AM 1

With best regards

Shafay

Hi Sir

Thanks a lot of you sir

unknown user

Do not understand your question - "why C axis reading move with spindle?" Please attach video to post. Could not access external web.

 If run a program in MDI S100 M3 ( only spindle) , you can see spindle run at approximately 100 rpm, also you can see that C-axis is move in software ( HMI screen  ), with out any program or command. Here We run only Spindle not C-axis.

and Physically C-axis is not moving but reading ( digit ) changed or move.

hope full you will be understand my question

with regards

Shafay

It seems that your C axis is set up as C axis on lathe (combined with spindle).

I thought that you have troubles with variation of spindle rotation for all week XD

After watching video all became clear, you should recommissioning kinematic chain for cardanic swivel head.

Read attached manual from page 451, page 501 is about kinematic types of mills.

Hi

PISCEAN Sir 

Have a nice day 

Spindle speed display varies between 647 to 653. Speed difference is 6 RPM. Even if set speed is assumed to be 650 RPM, +/- 3 RPM variation is not much. It is normal.

2. Since your system has common drive & motor for spindle & C axis with common encoder feedback (external encoder) C axis displays change in position value when spindle run. If you want to check, configure Spindle axis on motor encoder instead of external encoder & check

1st Problem.   

Spindle Variation is to much at 1500 rpm , You can seeing video  1482 to 1520. and sir I check Cable of motor encoder proper shielded, connection are fine connector to connecter wire resistance is less then almost or 1 Ohm,

2nd Problem.

Sir I can't understand that why machine is stop after 3 to 5 min due to these alarms, ( 22100, 25030) its serious issue for us.  

Is it due to spindle RPM variation or Motor encoder  or External encoder, or Parameter setting required or as Sir CNCNIK indicate the Setting in previous post ETC ?  

CNCNIK

It seems that your C axis is set up as C axis on lathe (combined with spindle).

I thought that you have troubles with variation of spindle rotation for all week XD

After watching video all became clear, you should recommissioning kinematic chain for cardanic swivel head.

Read attached manual from page 451, page 501 is about kinematic types of

 With regard

Shafay

Hi Sir 

Hope full  you will be fine.

Which video you are talking about?

Please attach video of screen display of spindle at 1500 RPM.

Please attach the snap shot of fault message 22100 & 25030 with complete text display.

 i already attached the 1500 video

https://www.youtube.com/shorts/8JXAfXZJWRA

 and alarms 

regard 

Shafay 

Hi sir Deep 

Have a nice day 

today machine behavior is change due to external encoder after necessary settings.

 Machine run fine approx. 750rpm  but when  run at 1000 t0 1500 rpm , machine stop due to anthers alarms

Encoder signal Polluted

machine running  fine at low rpm at  50 rpm to 900 rpm high RPM after 1000 is no working properly.

new alarm generate, Encoder signal Polluted 

after rest alarm than machine is working fine at 750 rpm.

regard