Scaling of axis
- Nondepietjes
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03 Mar 2017 16:37 #88938
by Nondepietjes
Replied by Nondepietjes on topic Scaling of axis
For my encoder scale of the z axis. i have turn the servo motor by hand and measer the real distance and compared it to the DRO. so the encoder scale of 500 should be right. If thats the right way to do? The linear encoder doas use indeed a conversion box and will needs some testing. But first i want to get my z-axis right. My only problem is that when i ask to move 10 mm or 5 mm or another distance. My machine is going verry slow and not 2000 mm/min. When i set my output scale lower then the machine goas faster but if i change my P-regulator up, my servo begin to make lot of noise an the machine goes slow again.
So i don't know what the OUTPUT_SCALE does.
So all together
- i can't get the machine to the right speed
- and the regulation of the machine goes difficult
So i don't know what the OUTPUT_SCALE does.
So all together
- i can't get the machine to the right speed
- and the regulation of the machine goes difficult
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03 Mar 2017 17:20 - 03 Mar 2017 17:28 #88941
by PCW
Replied by PCW on topic Scaling of axis
In general you should not change the default output scale or output limits (normally 10, -10,+10)
The only things that normally need to be adjusted for velocity mode servos are:
1. Encoder scale
2. P term
3. FF1 term
4. Maybe FF2
5. You may have to reverse the sign of output scale if the feedback is wrong (you get a runaway)
Have you gone through JTs tuning tutorial?
gnipsel.com/linuxcnc/tuning/servo.html
The only things that normally need to be adjusted for velocity mode servos are:
1. Encoder scale
2. P term
3. FF1 term
4. Maybe FF2
5. You may have to reverse the sign of output scale if the feedback is wrong (you get a runaway)
Have you gone through JTs tuning tutorial?
gnipsel.com/linuxcnc/tuning/servo.html
Last edit: 03 Mar 2017 17:28 by PCW.
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- Nondepietjes
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03 Mar 2017 21:52 #88964
by Nondepietjes
Replied by Nondepietjes on topic Scaling of axis
so there is no need to tune the I or D term?
And i have seen the tutorial but not properly done it.
surtenly many thanks for the help, i will let it know how it went or if i have other problemes
And i have seen the tutorial but not properly done it.
surtenly many thanks for the help, i will let it know how it went or if i have other problemes
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- Nondepietjes
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06 Mar 2017 13:25 #89092
by Nondepietjes
Replied by Nondepietjes on topic Scaling of axis
Hi,
I have adjusted a few things, but my servo still make some noise ( i think vibration)
anybody that now what the cause?
I have adjusted a few things, but my servo still make some noise ( i think vibration)
anybody that now what the cause?
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07 Mar 2017 02:55 #89121
by bevins
Replied by bevins on topic Scaling of axis
Vibration or oscillation?
Try dropping P until you get no Oscillation.
Try dropping P until you get no Oscillation.
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- Nondepietjes
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07 Mar 2017 12:39 #89130
by Nondepietjes
Replied by Nondepietjes on topic Scaling of axis
Hi,
First of all thanks for the help,i found the solution to my speed probleme. The servo's can go 2000 rpm. so i have calculated my velocity, so 2000rpm = to 7.33 m/sec.
Now my other problem is that when i jog into the limitswitch on one side ia hit the hard limt and can't jog away from it by pressing the overwrite button. The other side where the homing is there i can jog away.
there is one limitswitch for eatch axis. Can anybody help me find the problem?
Thanks again![;) ;)](/media/kunena/emoticons/wink.png)
First of all thanks for the help,i found the solution to my speed probleme. The servo's can go 2000 rpm. so i have calculated my velocity, so 2000rpm = to 7.33 m/sec.
Now my other problem is that when i jog into the limitswitch on one side ia hit the hard limt and can't jog away from it by pressing the overwrite button. The other side where the homing is there i can jog away.
there is one limitswitch for eatch axis. Can anybody help me find the problem?
Thanks again
![;) ;)](/media/kunena/emoticons/wink.png)
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07 Mar 2017 23:12 #89179
by rodw
Replied by rodw on topic Scaling of axis
You should never hit a limit switch if the machine is properly set up. It is just there for safety.
Reduce the length of the axis in the ini file so you don't hit it. It might only take a mm or so to stop it. happening.
Reduce the length of the axis in the ini file so you don't hit it. It might only take a mm or so to stop it. happening.
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- cncnoob1979
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08 Mar 2017 17:22 - 08 Mar 2017 17:26 #89213
by cncnoob1979
Replied by cncnoob1979 on topic Scaling of axis
When you have your scale correct in axis you can just measure using the DRO to set your actual travel limits. With your actual travel measured you will set your "soft" limits.
As rodw stated the actual limit switches are used for the "crap" (*^&*@#@) moments
They are there to save your hardware.
Find out what your actual travel limits are and set them in your ini file.
MIN_LIMIT = -500
MAX_LIMIT = 500
This is where you set the soft limits of the machine.
As rodw stated the actual limit switches are used for the "crap" (*^&*@#@) moments
![:) :)](/media/kunena/emoticons/smile.png)
Find out what your actual travel limits are and set them in your ini file.
[AXIS_0]
TYPE = LINEAR
HOME = 0.0
FERROR = 150
MIN_FERROR = 150
MAX_VELOCITY = 32.33333333
MAX_ACCELERATION = 20
P = 10
I = 0
D = 0
FF0 = 0.0
FF1 = 0
FF2 = 0.0
BIAS = 0.0
DEADBAND = 0.0
MAX_OUTPUT = 8
ENCODER_SCALE = 5000
OUTPUT_SCALE = 10
OUTPUT_MIN_LIMIT = -10
OUTPUT_MAX_LIMIT = 10
MIN_LIMIT = -500
MAX_LIMIT = 500
HOME_OFFSET = 0.000000
HOME_SEARCH_VEL = -1.000000
HOME_LATCH_VEL = -0.500000
HOME_FINAL_VEL = 0.000000
HOME_USE_INDEX = NO
HOME_SEQUENCE = 0
HOME_IGNORE_LIMIT = NO
MIN_LIMIT = -500
MAX_LIMIT = 500
This is where you set the soft limits of the machine.
Last edit: 08 Mar 2017 17:26 by cncnoob1979.
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