Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: fishin_fl on February 13, 2013, 07:39:12 AM
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Hello everyone. I have recently finish building my cnc and have ran into a couple things. I have done some reading but the few things I have tried have not worked. I have put 2 limit switches per axis. Using the two for limits and one of them for homing. I have them in series on each axis, one leg to ground and one to each designated pin. I am using pins 10, 11, and 12. Have not installed e-stop yet but will.
The problem I am having when enabling the Y and Z axis Mach 3 states that I have a triggered limit. I push the reset button and it does reset and then about 4-6 seconds later it says its tripped again. I go to diagnostics screen and there are no LED's lit for trips. Now I can enable X axis and the homing works. The axis moves to that point and it stops. And if I send the axis to trip limit it works.
Another problem that I things corresponds with my axis problem is that when I turn off X axis and enable Y axis and try to home. Y starts to move and then stops. Same with z axis.
I am stumped. I have checked my wiring and redid some wiring thinking I had a shielding problem. Any help will be greatly appreciated. Thanks everyone.
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Attach your xml and I'll have a look.
Brett
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raise the debounce interval to 3000. general config page, make sure you click ok.
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Brett I will attach xml file tonight when I get home. Thanks you.
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Angel tech I have increased my debounce to 1000. So I will also try that when I get home tonight.
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Well I went home and I increased the de-bounce. Seemed to work but still triggers once and awhile in movement. Al connections are tight and rerun. Here is the xml, made sure I saved current.
Thanks
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Hi Brett, I know this may seem strange but I had a similar problem see "limit switch activated triggered" after countless contact with Mach forum members I thought I had solved the problem HOWEVER!!!
This aproblem started 3 months ago when the machine stopped halfway thru a program saying limit switch triggered, I restarted and all was fine, however this got worse finally it would take 10 or more attempts before I could cancel the triggers, (again the diagnostic did not show errors). Finally after getting the machine started I worked all day on jobs with no problem. Switched off the machine and the computer but realised I had one more to do. The computer would not start. After investigations it turned out the computers power supply had blown, so bought another power supply, put it in the computer and all was fine. 3 days later the error started again " limit switch triggered" then guess what the power supply failed again. So bought a secondhand Dell Optiplex computer "because it had the printer port outlet" low and behold Mach3 has been working fine ever since with no trigger signals (fingers crossed). Guess what I'm saying is if all fails and you checked your machines earthing is good and you cant sort out the problem it might not be Mach or your machine it could be your computer. I don't think any upgrades in Mach are the problem as my initial problem was with a system I had been using for 4 years. I suspect there is a rogue signal from your computer, it turned out my old computer had a motherboard intermitten fault which caused the power supply to fail. I bought an old computer on ebay for a tenner and solved the problem. Good Luck, Jim
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Apologies Brett thought you had stated this thread, apologise fishin_fl for not noticing you had started the thread. It is 6 in the morning and ain't got my brain in order. jimthefish
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Thanks Jim, thats good to know.
fishin fl, what version of Mach are you running? Do you use any custom macros, brains, screen sets, plug-ins?
Brett
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Fishin, assign your estop to port 1 pin 11 and your X++, X-- and X home to port 1 pin 13 and move the wire to pin 13. Let me know if that gets it.
Brett
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Brett, I am new to mach3. Just downloaded the current mach3 off artsoft site. And bought license. I have not down anything yet to mach3 except default stuff I guess. I have a 1.34 hp spindle with a emerson ct vfd drive, I would like to control with mach3 by modbus or something. Maybe on/off, load meter, and maybe a little program to adjust feed rate if load has exceeded a certain perctange. I am also trying to figure out a vacuum hold down system.
Now for the other two axis just put in an input or a specific one? Thanks.
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I would leave y and z set up as you have them in the xml you posted earlier.
Brett
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Brett,
I did go home and change my pin out like you said to try. It worked for a while but still poped up. Limit triggered. I was told by somebody else to try replacing the push button limits to proxs.. What you think? Right now I turned off the limit switches but still using the home switches. I guess I could put in a soft limit for table but I still would like something redundant. Thanks for the help.
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The type of switch isn't as important as the quality of it. Either one are susceptible to noise which is what it sounds to me is your problem, noise. But, if I had my rathers, I would use mechanical switches as part of the e-stop circuit for the limit switches and use prox switches (24VDC) for the home switches. I am a firm believer in using 24 VDC for everything except step and direction, index signal, probes and MPGs. This requires more components, money, space, etc. You can, as many others do all the time, use 5V with great success but you have to be very mindful of noise. 24V has almost 5 times the noise immunity as 5V. Shielded cables and good wiring practices are the 2 main factors of getting the results you want, good clean consistent and accurate state changes. Good practices should be followed no matter what the voltage or what your wiring.
Brett
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With your response in mind. What would you recommend me buy to accomplish this.
My work uses automation direct parts but I am replacing stuff all the time. Thanks
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What hardware do you have now? You will likely need something to take the 24 volt signals and convert them to 5 volts. If thats the case you can find a ton of premade options or make your on. OPTO 22 is pricey but a pretty slick, robust way of doing it.
Brett