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VMC related HAL questions.

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04 May 2015 23:06 #58378 by thewho
VMC related HAL questions. was created by thewho
My previous topic in "Driver Boards" went a little off topic with a lot of HAL related questions.
So I thought it was time to start a new in the correct (hopefully) section of the forum.
I'm slowly getting closer to knowing how hal is done. Not good enough to write anything myself yet though :(

Quick info:
Machine: Modig MD5000 -85
Spindle: SK40 5krpm max, Lenze 4902 DC spindle drive (+/-10V control)
Control: Mesa 5i25+7i77

My most prominent problem at the moment is spindle speed compensation. Or lack of.. As seen in the picture below.
File Attachment:


Andypugh pointed me to this wiki page:
wiki.linuxcnc.org/cgi-bin/wiki.pl?SpindleOrient

Witch sadly doesn't help me (and my limited hal knowledge) much :huh:
I've attached my .ini and -hal files if they are of any interest.

So can somebody help me? :dry:
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09 May 2015 04:13 #58516 by thewho
Replied by thewho on topic VMC related HAL questions.
I've been reading up on the hal documentation and It's not that hard when you understand how it works.
But "spindle closed loop control" might be a little to advanced to start with :whistle:

The "Spindle Orientation" schematic makes a lot more sense now at least :)
Can the spindles two pid's be tuned via Linuxcnc? (cant remember what the tool is called) Or do I have to change the settings in the hal file?

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15 May 2015 03:24 #58705 by thewho
Replied by thewho on topic VMC related HAL questions.
Can I modify and use this on my machine?
wiki.linuxcnc.org/cgi-bin/wiki.pl?Closed...pindle_Speed_Control

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15 May 2015 17:36 - 15 May 2015 17:38 #58723 by andypugh
Replied by andypugh on topic VMC related HAL questions.

Can I modify and use this on my machine?
wiki.linuxcnc.org/cgi-bin/wiki.pl?Closed...pindle_Speed_Control


The Vismach model that I am playing with now has a closed-loop velocity spindle with orient (using M19)
so the HAL code to implement t this HAL diagram now exists as an example.

Unforunately it only exists on my machine at home.

If I get chance I will nip home at lunchtime and post it here. (as I am away all weekend)
Last edit: 15 May 2015 17:38 by andypugh.
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15 May 2015 19:09 - 21 Jul 2015 23:14 #58732 by andypugh
Replied by andypugh on topic VMC related HAL questions.
This is the complete simulated VMC (so far).

It will start up, home and run G-code.
It will also rotate the simulated spindle and respond to M19 commands.

Note that the orient component only updates outputs when motion.spindle-orient goes true from false, so to change orient angle you have to start the spindle and move it fractionally.

So,
M19 R45
M3 S10
M19 R180

Will work. (I might look at modifying "orient")

Tool changing is a work-in-progress. At the moment M6 is remapped to call an O-word subroutine, but the subroutine still does very little.
The G-code routine now does a complete tool change cycle for the simulated machine, but anyone using this code should make absolutely sure that it does all the necessary things in the right sequence for their hardware. Errors could be costly, but I am not in a position to test this code on your actual machine.

Extract the VMC.zip file into the configs folder and you should get a new config to choose in the LinuxCNC config picker.

You will need to give the "vmcgui" file execute permissions for the config to work.
(right-click, properties, permissions, from the file manager)

(Update 18 July) The carousel component now supports position-pulse + index mode
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Last edit: 21 Jul 2015 23:14 by andypugh.
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19 May 2015 03:48 #58832 by thewho
Replied by thewho on topic VMC related HAL questions.
I understand that Linuxcnc can "do it all" if you know what you are doing. But why isn't things like closed loop spindle control built in? Almost every machine controlled by Linuxcnc has a rotating spindle of some sort, yes I know that only a few have some sort of spindle position feedback but still..
Is it a time/prio thing?

Same with Pncconf, it's a great tool but I feel it could do so much more.

Thanks again Andy for helping newbies like me :)

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19 May 2015 04:04 #58835 by andypugh
Replied by andypugh on topic VMC related HAL questions.

But why isn't things like closed loop spindle control built in?


It isn't generally necessary, for one thing. Exact spindle speed isn't that important. Before VFDs machines would only run at 6 or 8 fixed speeds, and nobody worried about it too much.

Even now, you don't particularly care about exact speed, just too fast and too slow.

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19 May 2015 18:18 #58856 by BigJohnT
Replied by BigJohnT on topic VMC related HAL questions.

Is it a time/prio thing?

Same with Pncconf, it's a great tool but I feel it could do so much more.


If only you knew how complex Pncconf is and how many thousands of hours the author spent writing it.

Spindle feedback is in the manual.

JT

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19 May 2015 22:56 #58862 by andypugh
Replied by andypugh on topic VMC related HAL questions.

Spindle feedback is in the manual.


Some of it is in that zip file too :-)

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20 May 2015 06:39 #58879 by andypugh
Replied by andypugh on topic VMC related HAL questions.
OK, I now have the whole thing working. In the end I settled on a G-code subroutine for the tool-change sequence after finding a serious design flaw in my sequencer component.

This is a video of the tool change in action:


And here is the G-code that does the change.
o<toolchange> sub

M19 R0  ;align the spindle

; only unload the tool if there is a tool in the spindle
; This assumes that the carousel is already aligned correctly. 
; It is important to unload the tool before shutting down the machine. 

O100 IF [#<tool_in_spindle> GT 0]
    G53 G0 Z -100
    
    M64 P2 ; move arm in
    M66 P2 L3 Q5 ; wait for arm-in = true
    O104 if [#5399 LT 0]
        (abort, failed to move arm in)
    O104 endif

    M64 P3 ; release tool
    M66 P3 L3 Q2 ; wait for tool-released = true
    O105 if [#5399 LT 0]
        (abort, failed to release tool)
    O105 endif

O100 ENDIF

    G53 G0 Z0

O200 IF [#<selected_tool> GT 0]

    M65 P1 ; unlock carousel
    M66 P1 L4 Q1 ; wait for locked=false
    O106 if [#5399 LT 0]
        (abort, failed to unlock carousel)
    O106 endif

    M68 E0 Q#<selected_pocket> ;set the carousel to move to the right pocket

    M64 P0 ; start carousel
    G4 P2
    M66 P0 L3 Q60 ; wait for carousel finished
    O107 if [#5399 LT 0]
        (abort, failed to align carousel)
    O107 endif
    M65 P0; stop carousel
    M64 P1 ; lock carousel
    M66 P1 L3 Q1 ; wait for locked=true
    O108 if [#5399 LT 0]
        (abort, failed to lock carousel)
    O108 endif

    M64 P2 ; move arm in (might already be in)
    M66 P2 L3 Q5 ; wait for arm-in = true
    O109 if [#5399 LT 0]
        (abort, failed to move arm in)
    O109 endif

    G53 G0 Z-100 ; pick up the tool

O200 ENDIF 

M65 P3 ; clamp tool
M66 P3 L4 Q2 ; wait for tool-released = false
O110 if [#5399 LT 0]
    (abort, failed to clamp tool)
O110 endif

M65 P2 ; move arm back out
M66 P4 L3 Q5 ; wait for arm-out = true
O111 if [#5399 LT 0]
    (abort, failed to move arm in)
O111 endif


o<toolchange> endsub [1]


M2
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