mesa 7i76e vfd spindle speed problem

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01 Sep 2021 15:46 #219348 by Raban
Hello guys ,


I am a new forum user( Italy near Venice) , and i apologize if am posting in the wrong forum .

I have a milling machine 3 axis with stepper motor , vfd for spindle , encoder ABZ single ended for spindle speed
connected to a mesa 7i76e card
X , y , Z , limit and homin work correctly .

The problem is the vfd , cw and ccw work , but the spindle start at maximum speed ( about 100hz) both on axis and on gmoccapy , if I use the m4 and m3 commands, the spindle always goes to maximum rpm .

Voltage from TB4 pin 1 and TB4 pin 3 is +10v ( source from VFD)
Voltage from TB4 pin 2 and TB4 pin 2 is +10v ( an this is not correct)

Spindle rpm slide i gmoccappy is locked ( second problem )

I can't understand if with my HAL configuration the spindle work with encoder feedback or not ( third problem )

My English is bad ( an this is the fourth problem )


I thank everyone for all the suggestionsI attach files hal and ini 

File Attachment:

File Name: my_LinuxCN...hine.hal
File Size:12 KB

 

File Attachment:

File Name: my_LinuxCN...hine.ini
File Size:5 KB
Attachments:

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01 Sep 2021 16:00 #219349 by aleksamc
At first, in INI file you have
[SPINDLE_0]
P = 0.0
I = 0.0
D = 0.0
FF0 = 1.0
FF1 = 0.0
FF2 = 0.0
BIAS = 0.0
DEADBAND = 0.0
MAX_OUTPUT = 6352.94117647
ENCODER_SCALE = 566.66
OUTPUT_SCALE = -6352
OUTPUT_MIN_LIMIT = 0
OUTPUT_MAX_LIMIT = 6352
P - can't be zero, you should set 0.2 or something like this.
You doesn't use encoder feedback for spindle, it's seen from your hal-file.
You should start spindle with M3 S1000, where s1000 is velocity of spindle and you should set it.
 

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01 Sep 2021 19:06 #219357 by Raban
P= 0.2 result
M3 S300 spindle 8000 Rpm
M3 S1000 spindle 6800 rpm
M3 S3000 spindle 3600 rpm
M3 S4000 spindle 2000rpm
M3 S5000 spindle 470 rpm

Encoder reverse ?

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01 Sep 2021 20:14 #219362 by PCW
P=0 is OK the just means you are running the spindle open loop
I would leave it at 0 unless you need closed loop speed control

But in your INI file:

OUTPUT_SCALE = -6352

is not right, this must be positive since the
7I76E analog out is unipolar

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03 Sep 2021 07:18 #219496 by Raban
Thanks ,
with a positve parameter work !

Why pncconfig set a negative parameter ?
And for rigid tapping setup is complete o a need to run vfd with feedback from encoder ?

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03 Sep 2021 14:11 #219519 by andypugh

And for rigid tapping setup is complete o a need to run vfd with feedback from encoder ?

You need a spindle on the encoder for rigid tapping, but it only needs to connect to LinuxCNC, not to the VFD.  And there is no need for closed-lloop spindle control. 

For rigid tapping there is a closed feedback loop between the spindle encoder and the Z axis inside LinuxCNC. 
 

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03 Sep 2021 14:33 #219527 by Raban
I apologize, the rigid tapping question is not done correctly ;

my configuration is asynchronous motor with 200 ppr A+B+I TTL encoder connected to mesa card.
The VFD is controlled by the mesa board with the 0-10V output.
Is this enough for rigid tapping? Do I need to make other changes to my HAL file?

Thanks

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03 Sep 2021 14:39 #219530 by andypugh
If the encoder turns 1:1 with the tool then your setup will work.
If there is any gearing between the encoder and the spindle then you might need to arrange a separate index and adjust the encoder scaling.

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03 Sep 2021 14:44 #219531 by tommylight

You need a spindle on the encoder for rigid tapping, ...

Or the other way around? :)

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03 Sep 2021 15:16 #219535 by Raban
On the motor i have a 48 teeth pulley and 34 on the spindle.
The 200 ppr encoder is on the motor 1:1
(200ppr x 4 )/48 x 34 = 566,666667

ENCODER_SCALE = 566.66

In gmoccapy the speed in rpm is correctly displayed with a + -3% jittering

example :

M3 S300 gmoccapy show speed 290-310

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