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Axis direction doesn't always change
« on: May 11, 2017, 03:21:02 PM »
Friend of mine's computer died & I had one that I had been using before making some upgrades, machine is running windows 7 32bit via the parallel port & has been optimised to run mach3. This computer had been running my CNC for a couple of years without any problems. I removed myself as a user & deleted all my files, removed my licence file for mach3 & installed my friends licence code & the profile that he had been using with his old computer. Those were the only changes to the computer.

Now it is hooked up to his cnc machine the Y & Z axis seem to be working as normal but there seems to be a random problem with the X axis. If you press the left arrow key the machine moves to the left as it should or if you press the right arrow key it moves to the right as it should. The problem is that on occasions if you move to either the right or left (doesn't seem to matter) then move in the opposite direction the machine carries on moving the way it had previously been moving rather than changing direction  :)
I thought this may be a keyboard problem but I have now tried 3 different keyboards & same thing happens with them all, every now & again the axis doesn't change direction when it should. Haven't tried cutting anything to see if it does the same thing when cutting just in case there was a problem  

Offline ger21

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Re: Axis direction doesn't always change
« Reply #1 on: May 11, 2017, 06:05:26 PM »
It's most likely the voltage on the direction pin.
Gerry

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Re: Axis direction doesn't always change
« Reply #2 on: May 12, 2017, 06:00:20 AM »
OK I can check that thanks ger21 but what would cause the voltage to be different on just one pin & is there anything that could have caused it to change, I never had a problem like this when I was using the computer with my machine. Only reason I changed my computer was because I had a spare one & set that up to work with an ethernet motion controller. Using a different comtuter meant that if I hit a problem I knew I could always switch back if I had a problem  :)
His cnc electronics are different to mine, BOB, drivers & power supply but I wouldn't have thought that would make a difference.
Re: Axis direction doesn't always change
« Reply #3 on: June 18, 2017, 02:01:23 PM »
I had a router for about two years and from the day i got it i had a problem with Y axis running rough and changing direction. About two weeks ago i found a lose wire on the control board which fixed all of my problems for the past 2 years. I hope your problem is that easy to fix.

good luck
Bob
Re: Axis direction doesn't always change
« Reply #4 on: November 08, 2017, 08:05:21 PM »
I forgot I had asked this question lol, the guy had an accident (welding) & hadn't been near the machine since I asked this question the first time round. He now wants to try & get things moving so he can use it again. voltage on that particular pin seems to be fine.
Tried several keyboards just in case it was a keyboard error & still the same problem, sometimes it jogs the right way & sometimes it doesn't. There doesn't seem to be any consistency to it. Even if you just keep jogging in the same direction at some point it starts to travel the other way.
Ran a gcode file that I knew was good & he had cut before with the old computer & it does exactly the same thing so not just a problem with jogging from the keyboard.
Sure someone must have experienced this problem in the past lol
Re: Axis direction doesn't always change
« Reply #5 on: November 09, 2017, 02:04:32 AM »
Hi,
sounds like noise to me. Try Config/General Config... upper right corner 'Debounce Interval' , make it 20 and see what happens.

Craig
My wife left with my best friend...
     and I miss him!
Re: Axis direction doesn't always change
« Reply #6 on: November 09, 2017, 04:34:58 AM »
Will give that a try Craig & report back, the machine has shielded cables, is correctly earthed & was running fine prior to the old compute melt down but anything is worth trying lol
It is just the one axis as well, what I haven't done which might be worth trying is switching the cables for X & Y axis to see if the problem moves.

Offline Tweakie.CNC

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Re: Axis direction doesn't always change
« Reply #7 on: November 09, 2017, 08:05:10 AM »
Hi Martin,

You need to leave the voltmeter connected to the axis direction pin. Make a note of the voltage for each direction of the axis movement when jogging. When it goes in the wrong direction is the voltage correct for that axis direction ?

Tweakie.
KEEP SAFE !
Re: Axis direction doesn't always change
« Reply #8 on: November 09, 2017, 09:18:59 AM »
Hi Martin,

You need to leave the voltmeter connected to the axis direction pin. Make a note of the voltage for each direction of the axis movement when jogging. When it goes in the wrong direction is the voltage correct for that axis direction ?

Tweakie.

I did check the voltages with the axis moving for both X & Y axis but it was just a quick check & I honestly don't know if the axis was moving the right or the wrong way so will check that again but be a bit more thorough lol, what would cause the voltage to change & what would the fix be if I found there was a difference ?
Would like to go back & be able to sort this rather than keep having to make trips out to see him.

Offline ger21

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Re: Axis direction doesn't always change
« Reply #9 on: November 09, 2017, 10:40:12 AM »
The direction voltage is 0V in one direction, and 5V in the other direction.
If it's not, it could be a lot of things. If it's 0 and 3.3V, then that could mean you have a 3.3V parallel port. In that case, you'd need a breakout board that works with 3.3V.
Gerry

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JointCAM Dovetail and Box Joint software
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