Sinamics Servo Position Error

Hi Guys,

   I am using siemens servo motor v90 with absolute encoder,s7 1200 plc cpu 1215,modbus communication.in my application i am using rotary axis,0 to 360 degree,i am facing a problem after some revolution or running my machine, i am getting position of initial shifted,can you give some idea please.

Regards 

shanthakumar

Maybe the number of encoder lines are not  correct in the plc

Also reference speed should be okay

Hi,

 Thank You for reply,i am not using additional encoder,i have sinamics v90 servo amplifier,servomotor.

i have doubt in my mechanical ratio

Gearbox 5:1

Pulley 29 teeth

Belt 238 teeth

Pulley Diameter 184.62mm

Belt Length:2460

What is the gear ratio i have to enter in my v assistant drive

Regards

shanthakumar

Your belt is not relevant.  What is relevant is the gear ratio and the ratio of your two pulley diameters (the two pulleys that the belt connects).

So if your gear ratio is 5:1 and the pulley that is attached to the gearbox is 100mm and the diameter of the second pulley is 200mm, then your effective gear ration is

5 * 200/100 = 10 : 1.

Hi,

  Ok thank you i will try,my motor shaft connected to gearbox,my gear box shaft coupled with one more shaft ,the shaft is connected to my table pulley,this is my design,now i know my pulley diameter,one more diameter which one i have to considered,Pls find the attached image.

Regards

shanthakumar

As explained earlier, your pulley diameter is the ratio of the diameter of the pulley that your motor is connected to and the pulley which is turning whatever is supposed to turn.  You do know that a belt is attached to 2 pulleys, right?

And please do not repost identical questions.  https://support.industry.siemens.com/tf/ww/en/posts/mechanical-gear-ratio/164114/?page=0&pageSize=10

Hi,

 Thankyou for your reply,sorry for posting identical issues,is there any error create fraction of decimals.foe example

my ratio is 5*8.20689655=41.0344828

Regards

shanthakumar

yes, there will always be rounding error.  use as many decimal places that are significant.

You do realize that you are off by 1 decimal place in your posted example.  Also, I question that your pulley ratio is 8:1.  I've never seen anything that high before.  1:1 - 2:1 would be more typical.

Hi,

 How to solve the rounding error ,Any Idea because i can't change my mechanical set up,is there any possibilities

Gear Teeth=238

Belt Teeth=29

Ratio 238/29=8.20689655

Standard Ratio=1:5

Regards

shanthakumar

Could you post a diagram of your entire mechanical transmission system?

The number of teeth in your belt is not relevant!!!!!!!!!!!!!!!!!!!!!!!!!!!