Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: sooperdrave on September 19, 2008, 10:09:08 AM
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my x and y axis will just stop working in the middle of programs or in the middle of jogging. when this happens i have to shut down the whole system to get them working again. sometimes when the x axis stops working i will wait a few minutes and it will come back on its own. also the dro for both axi read as though the axis is still moving. any ideas? i really need some help as i have tried everything i can think of.
ps. im still a noob at fixing problems with mach three.
dave
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Sounds like a hardware issue but next time it happens have a voltmeter ready and check that the step signal is coming out of the parallel port, you can do that by connecting the voltmeter between the X axis step pin and a ground pin, have the voltmeter on milli volt range and if its working you will see a voltage which will change with speed.
Hood
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thanks hood, are you saying this is a connection problem? im thnking that the signal from the breakout board is not getting to the axis motor controllers. if its a hardware problem would it be the servo motors or the computer?
dave
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hi hood, you said to check the step pin and the ground pin..... are those on the break out board or the motor? i tink i know what your saying but im a noob so bear with me..lol
dave
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dave
not saying its definitely a hardware problem but just sounds more likely than software especially as the DROs keep moving in Mach.
You can check either at the outputs of the breakout or the Inputs on the drives. If you dont get a signal there then you need to check from the parallel port. If you dont have an E-Stop in your system then its easy enough to do, when the axis stop moving but Mach is continueing then just pull off the cable from the parallel port and put your voltmeter on the X axis Step pin and the other lead to the ground of the PP. So its a good time to make sure you know which pins are which so that the next time it happens you are ready :)
Hood
Hood
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i know what to do now and i checked out the pins and what-not and i know what im looking at now. you said its easy enough to do if i dont have an e-stop in my system. i do have an e-stop in my system so, can i still do it this way or do i have to do something else?
thanks for the help! :)
Dave
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The problem will be that when you haul the cable off the port the axis will stop as the E-Stop will trip, same with limits.
Just read your first post gain and one good thing is you have to restart to get things working again so if it stops working stop the code, go into Ports and Pins and change the active state of limits and E-Stop and remove the cable from the parallel port then start the code running again and measure the voltage.
Hood
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got it! now my last question is how can i find out which pin in the parallel port is the ground pin.
thanks
Dave
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18 to 25 are grounds
Hood
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thanks hood.
i did the test and it was sending the signal to the motor so I'm assuming that the problem is the signal from the motor to the x axis on the saw itself? what do you think?
Dave
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Bit confused as where you measured, was it at the drive?
If it was then looks like its either a drive or motor problem, try swapping the drives around and see if the problem follows the drive.
Hood
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hi hood.
yes the problem followed the drive. i took the drive apart and cleaned all the dust out of it and now it works fine. i work in a wet environment so i think some moisture was getting into the drive. combine the moisture and the dust and i think it was shorting out.
thanks for the help!!!
dave
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excellent news :)
Hood