Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: cristian gabor on December 23, 2008, 09:09:32 AM
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hi
i have had my plasma table running for 6 months on belts
and decided to go for rack & pinion drive. all worked fine until my
servos do not engage anymore .
I have a button on my controller (logitroll 20 amp ametek servos )that
if i push up for 3 sec it engages (activates ) the servos or from
active mode if pushed down deactivates the servos.
when my computer is of or if i unplug the parallel cable from computer
,i can activate the servos everything is OK
but when the computer is on (does not mater if mach is running or
not)the servo do not engage.
when i push the button to activate the servos they try to move and
deactivates
or if i keep the button pressed the 3 axis move rapidly and get
deactivated and move again (hi speed very short moves ) and so on
until i release the button.
there is another situation when i unplug the parallel cable, activate
the servos then plug back the cable and play whit it like everything is OK
please help
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You will have to provide more info, especially the type of drives and where that switch comes into the equation. Did you build the machine yourself or is it a bought machine? Do you have a wiring diagram?
Hood
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hi hood
it is a 20 amp servo pak ametek servos/us didital encoders from "lowcostcncretrofits"
the machine it is build by my
inside the controller box are 3 gecko320 drivers
the machine did run well before the modification
it runs well at this moment if i unplug the parallel cable from the comp /engage the servos/plug back the parallel cable and then jog around
or if i go in device manager /disable the parallel port/engage the servos/enable the parallel port and then jog around
i have fitted a second parallel port on the comp /set it as port 1 in mach but the problem is still there
i measured the voltage across the parallel cable (unplug-ed from the controller box ) and found 5 v on pins :3,7,8,10,11,12,13,15.
from those pins3 and 7 that have 5v on them corespond to x dir and z dir
my setup for the 3 axis is as follows:
step dir
x 2 3
y 4 5
z 6 7
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if i disable port1 in mach or if mach is not running the problem is still there
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Where/how is the switch wired? Is it to the Geckos?
Hood
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yes
is bewin pin 5 and pin 12 on geckos and - one side of swich goes to grouund (0 v )
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I am not familiar with Geckos servo drives but will look and see what these pins correspond to.
Hood
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http://www.geckodrive.com/upload/G320-REV-7-Manual.pdf
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OK so do you have a wire going back to the computer to signify the fault? If so then do you have that wired properly and set up properly? I would presume you have that to Input 1 in mach?
Hood
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the only wire going to comp is parallel cable
yes is set to port 1 in mach
and i veryfied the wiring to encoders and motors and is ok
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But surely you have pin 5 connected to Input1? If so have you got that se corectly in Mach?
Please attach your xml and I will look.
Hood
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hi hood i could not upload fth xml file on mach suport forum so i uploaded on the file cnczone forum
http://www.cnczone.com/forums/showthread.php?t=70286
cris
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Just had a look at your xml and I see you dont have Input 1 enabled and also you dont have this set in General config to stop Mach if the signal is active. This could be your problem if you do have the fault line going from the drives to Mach.
Another thing I noticed is you have Output 1 enabled for bot the Spindle and also the Flood and Mist coolants, is this meant?
Hood
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hi
done more digging and found this:
1. power up PC /engage servo and all is god (then disengage by hand)
2. turn on mach /engage the servo/the servo disengaged by themselves
3. grab voltmeter/restart the PC /read the parallels port pins and found 3.8 volts on all pins from 1 to 16
4 open mach and read again all the pins and found that i only have 3.8 volts on pins : 2 (x step) , 6 (z step) and some others but no on pin 4 that is y step
5 the found that if i change "y Dir" to "lo activ" i get 3.8 volts on pin 4
so now i can engage the servos BUT while holding the switch up to engage the servos the z axis moves down
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HI ;)
PROBLEM SOLVED
FOR SERVOS TO ENGAGE IS NEED TO HAVE 5 VOLTS ON STEP PIN FROM PARALEL PORT THAT GOES TO PIN 11 ON GECKO 320 DRIVE
MY STUP WAS: PIN 2 FOR X STEP PIN 4 FOR Y STEP AND PIN 6 FOR Z STEP FROM THE PARALLEL PORT
(ASIGNED IN MOTOR OUPUTS / MACH )
(AND WIERED PROPRELY )
(AND I DID RUN THIS SETUP FOR 6 MOUNTHS WHIT OUT ANY PROBLEM)
BUT FOR SOME REASON I COULD NOT HAVE 5 VOLTS ON PIN 4 FROM PARALLEL PORT SO I CHANGED THE STEP PIN IN MOTOR OUTPUTS TO PIN 8
REWIERED GECKOS PIN 11. TO PIN 8. ON PARALLEL PORT AND EVERITHING IS OK NOW
THANKYOU HOOD FOR YOUR ASISTENCE
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Maybe you changed the active state of the Step pin by mistake? But if its working now then great :)
Hood
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hi
the problem came back
and i'm going thru all the atory again
the story goes like this :
had my plasma table running OK for 6 months on belts
and because i could not get accurate cuttings due to belts elasticity i decided to build another one on rack & pinion
so i made the new table whit the controller computer to fit on gantry to keep cables short not to get any interferences
got the electronics down from the old one
fit the same servos on the new table
got the PC , power source of the servos and controller on the gantry (just placed them on the gantry not proprely fitted )
and run tests.
up to this point i had no problems
then decided to fit them proprely
so i opened my PC / striped down /got the motherboard power source hard drive and all other boards and fitted them inside the gantry
(i have builded a case for the electronics on the gantry)
whit the power supply of the servos and the controller box
THIS IS WHERE IT STARTED MALFUNCTIONING
THE PROBLEM IS THAT I CAN NOT ENGAGE THE SERVOS WHILE MACH 3 DRIVER IS RUNING.
HERE IS WHAT I FOUND UP TO THIS TIME :
IF I ENGAGE THE SERVOS WHIT PC OF THEY DO ENGAGE
IF I ENGAGE THE SERVOS WHIT THE PC ON BUT DO NOT RUN MACH THE SERVOS DO ENGAGE
IF I ENGAGE THE SERVOS WHIT THE PC ON AND MACH RUNING THE SERVOS DO NOT ENGAGE ANYMORE
IF I ENGAGE THE SERVOS WHIT THE PC ON AND MACH RUNING AND DISABLE THE PARALLEL PORT IN DEVICE MANAGER I CAN ENGAGE THE SERVOS
IF IN ANY CASE I ENGEGE THE SERVOS THEN I CAN JOG ALL 3 AXIS LIKE EVERY THING IS OK
SO IF I CAN GET THE TABLE MOVING ON THE 3 AXIS FROM MACH IT LOOKS LIKE DRIVERS ARE OK AND MACH IS OK (OR MAYBE NOT ?)
I ALSO DONE THIS :
INSTALED A NEW PARALLEL PORT ON THE PC - SAME PROBLEM
PLUGED IN A DIFERENT PC THE SAME PROBLEM
GOT THE CONTROLLER ISOLATED FROM THE TABLE - SAME PROBLEM
GOT THE PC SECOND PC ISOLATED FROM THE TABLE - SAME PROBLEM
all the cables were checked and they are OK (i can jog all 3 axis if i can get the servos to engage)
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Please tell us how you have the Geckos fault/reset circuit wired, especially with regards to which pin you have connected to the computer, I have never had Geckos servo drives so have no experience but from looking at the wiring diagram it seems to me this is where your problem lies.
Hood
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hi here is the connection of geckos to the system
do they work OK if i engage before running mach
gecko drive pins :
1. 0v from servos power supply
2. (+)50 v from servos power supply
3. M (-)
4. M (+)
5. soldered to engage/disengage switch
6. 0 v encoder
7. (+) 5 v encoder
8. A channel to encoder
9. B channel to encoder
10. dir pin from pp
11. step pin from pp
12 (+) 5v from controller power supply
the switch is a 3 pin switch that makes contact only while the button is pressed up for engaging/down for disengaging
___________ ( + ) 5 v
/
gecko's pin 5 _____/
\
\ __________( -- )
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OK I was under the impression you hd the fault wired as in the manual back to Mach but you dont from the above drawing.
Where does your 5v to pin 12 come from?
Hood
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controller's power suply
the controller is in a case factory made (hopfuly ) and it did run for 6 months so it sould be no problem there
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Is that the same 5V supply that feeds your switch?
Hood
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yes it is the same 5 v
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If you put a voltmeter across the 5V supply and its 0V (when PP cable connected to the computer) and press the switch does the voltage drop away?
Hood
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it does not hapend any thing
the voltage stays to 5 v
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Well afraid I have no idea, it certainly seems like when you have the PP connected it is not allowing your 5v signal to the fault line of the Gecko but as you have said you dont have the fault line connected to the computer then I am at a loss how this could be.
Hood
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when i power up the controller i have 5 v on step and dir term of the geckos is this normaj ?(pp not conected)
or it may be some return voltage