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Offline Fastest1

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limit switches/ estop?
« on: March 12, 2009, 02:22:41 AM »
I just built a HCNC Pro 4 axis controller and all is working except the limit switches. I think its a setting issue not hardware. Ok right now I have a mushroom switch that is n.o., closing the circuit makes mach3 stop via T5 grd and pin 10. That all works great. I can reset the flashing red icon on the screen after pulling out the mushroom and everything works great. I have estop enabled and set to active low. NOW if I hook up T5 ground and pin 11 to a set of series wired switches (continuity til switch is pushed). It will work according to mach3 as long as the hcnc is not powered up? The second I actually power up the board the limit switch flashes even if nothing touched it. I cant seem to reset it. Just stays flashing. I even tried it while disconnecting and disabling my estop, still triggers a limit warning and all control stops. What am I missing? This is just the z limits at the moment. I am
using 24/2 shieded. I have tried with active low selected and not selected. Seems to be no difference. Is there a switch/selection to jog off a limit? Everything
I read acted like a series connected set of switches were the cats meow. ?


I want to die in my sleep like my grandfather, not like the passengers in the car! :-)

Offline Hood

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Re: limit switches/ estop?
« Reply #1 on: March 12, 2009, 03:20:02 AM »
Do you see the LEDs for the limits, on the diagnostic page , showing they are triggered? If not then it is likely to be noise so try setting the debounce Interval to 2000 (Config menu then General Config page) If that helps then best to check all your shielding again making sure it is only grounded at one point in your cabinet.
Hood

Offline Fastest1

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Re: limit switches/ estop?
« Reply #2 on: March 12, 2009, 07:49:29 AM »
Yes the led does light up when the switch is triggered. Though I am using shielded wire, I havent tied the grounds down on the limit switch yet. I do have the steppers grounded so I thought it would be acceptable for the test. I was wondering if using a n.o. switch for the e stop and a n.c. string of series connected limit switches were conflicting with each other because of a shared ground. The estop is on pin 10 and limits for z are on 11. Is that an issue?
I want to die in my sleep like my grandfather, not like the passengers in the car! :-)

Offline Hood

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Re: limit switches/ estop?
« Reply #3 on: March 12, 2009, 09:00:51 AM »
I am meaning do you see the LED light when it FALSLY  triggers, is so try the Debounce Interval.
No having the limits and E-Stop on different pins is the proper way however a NC E-Stop would be better as if its a NO then Mach (and you) will never know a wire has broken or fallen off until you need the E-Stop and then it wont work.
Hood

Offline Fastest1

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Re: limit switches/ estop?
« Reply #4 on: March 12, 2009, 10:01:51 AM »
Hood
Thank you so much for the timely responses. I did think about the repercussions of using the switch I had. It is a switch with both options (NC/NO simultaneously) however I am using the NC side to depower the spindle when pressed and the other side triggers the mach to stop. The nc side of the switch also shows 110v so I didnt want it to connect with the board. I am going to install a toggle switch on the spindle also to allow safe tool changes without interuption of the gcode. If this is all possible. I believe it is. I will test the debounce setting in an hour or so, would that have an effect even if the switch was never touched? It seemed to do it regardless when/once I powered up the box. Seems to work great prior to powering up. It does sound like an induction/interferernce problem or my limited understanding of it. Not being a machinist/electronics/computer/cad student or tradeperson (I do have quite a bit of low voltage experience, media systems and window covering automation) it has been funny when you realize the vocabulary in all of the technical jargon and what it finally starts to mean after endless nights of reading in many fields. I spent so much time testing my HCNC pro board and mach software trying to get the steppers to jog that by the time they jogged, I understood so much more about the software. All of those problems were because I used a  defective ribbon cable between the board and the chassis jack I insisted on using. A little anal about appearance. Why else would we be interested in any of this otherwise? I have a problem gettiing absorbed deeply and not sleeping/eating acknowledging anything else til completion. I thought it was exciting, that is why I commit. Sorry for the life story and Thanks again for the responses. I do notice you help many people here as I have been reading as a guest for quite a while.
« Last Edit: March 12, 2009, 10:04:10 AM by Fastest1 »
I want to die in my sleep like my grandfather, not like the passengers in the car! :-)

Offline Hood

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Re: limit switches/ estop?
« Reply #5 on: March 12, 2009, 10:31:35 AM »
The ideal setting for the Debounce Interval is zero but you need to have everything wired well when it comes to the shielding for you to get that. Routing the limit cables close to any power cables can cause a fair amount of noise and Mach is very sensitive at picking up limit signals and it seems to be the case with yours.
  I have the limits on my Lathe and Beaver Mill on 24v and change this to 5v just prior to the signal entering the breakout board, 24v is much more imune to noise than 5v for the simple reason that the difference between Hi and Low is much greater in the 24V system.
 My Bridgeport just has 5v to the optical limits but I took care to shield the wires properly and tried to keep them routed away from mains wiring, I have the debounce as zero, so it shows that it can work. If setting the debounce to 2000 helps then its time to look at the shielding and cable routing.
Hood

Offline Fastest1

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Re: limit switches/ estop?
« Reply #6 on: March 12, 2009, 10:58:55 AM »
I cant wait to try it! Unlike old or new political parties in power, you do instill HOPE! John
I want to die in my sleep like my grandfather, not like the passengers in the car! :-)

Offline Hood

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Re: limit switches/ estop?
« Reply #7 on: March 12, 2009, 11:47:40 AM »
Unlike old or new political parties in power, you do instill HOPE! John

I will reserve my comments about politicians to the ones in my own country :)
Well unless I am talking to Brett as its fun winding him up
Hood

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Re: limit switches/ estop?
« Reply #8 on: March 12, 2009, 01:25:37 PM »
I thought I had responded. Anyway landed the shields to the chassis ground, and tried debounce at 2000 and then again at 4000. The delay before self triggering was longer than with no debounce but not much. Any other ideas? Again as long as power is off, estop and limits respond like they should, or as desired.
I want to die in my sleep like my grandfather, not like the passengers in the car! :-)

Offline Hood

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Re: limit switches/ estop?
« Reply #9 on: March 12, 2009, 04:53:00 PM »
Ok as a test take out the limits wiring from the breakout board and jumper a short wire accross from pin 11 to Gnd and see if you still get the same issues.
Hood