Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: JD2016 on July 18, 2016, 04:31:08 PM
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I embarked on a cleaning/lubrication routine with my G0704 mill over last weekend. However, when I attempted to jog through each axis there were problems with not moving at all and moving in the wrong direction. For example, it should have moved in X- direction, but both arrow keys would result going in the X+. Then the Z would move in the positive direction, but not at all when attmpting to move in the negative. This would happen a few times, work correctly for awhile, and then start acting up again. All the connections seem secure and there has been no changes to hardware or Mach 3 settings. There were no error messages from Mach 3 or UC100. My machine has the following hardware:
UC100 USB motion controller
(2) KL-5056D drivers
(1) KL-8070D driver
(2) KL23H2100-50-4B, NEMA23 570oz/in 5A 3/8” Dual Shaft Stepper Motor
(1) KL34H295-43-8A, NEMA34 Stepper Motor – 906oz in 6.1A Single Shaft
48V/12.5A Power Supply, 115V/230V
KL-DB25 BOB
Mach 3
I am not sure if this is a hardware and/or software issue. Would should I start to rule out to trouble shoot this? Thanks.
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Physically check your direction signal wires between controller & drivers, I'd be tempted to get a meter on the job,
- Nick
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I suspect you may have gotten cleaner/lubricant into the motors or motor wiring. Or maybe even just jostled the wires loose in the connectors. Just my $.02
Stephen "Highspeed" Kruse
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Drivers, BOB, and power supply are in a control box and wiring for motors are contained within motor covers, so isolated from lubricant. The cleaning didn't involve any chemicals, and the lubricant has been used may times before and was no where near wires/components. I went the over connections and all seem secure. This is frustrating to say the least considering everything was working fine. I am by no means electronic proficient, so excuse me if my questions seem stupid. Specifically how do I check with a meter direction signal wires between controller and drivers? What numbers should I be looking for? Anything else to check? Thanks.
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Yep, you're correct in assuming that you need to check the direction lines (at least in the case of the X axis), but not sure how to really explain the use of a meter briefly enough to state in a forum post. The Z axis acting the way it does (intermittently) still indicates to me something is loose somewhere or a wire got broken inside the insulation. It definitely seems weird that this happened from routine maintenance (cleaning/lubrication) of the machine.
The other possibility is that something got shorted out in the drivers as a result of liquid getting into the contacts or wiring pins touching while power was applied. I'm sure, though, that you didn't do this maintenance without turning off the machine first, right?
Could you try swapping the motors to different axis drivers and see if the symptom follows the motor or stays with the driver output? BE CAREFUL doing this as you'll easily get confused as to which axis should be moving for a given control and you may crash your spindle, tool or other components against other things and this is not good. Just short, slow movements to verify the driver/motor is working correctly. If the symptom stays with the motor, your drivers are good and you need to inspect the wiring more closely including weird kinks in the insulated sections where there may be broken wiring inside.
Let me know what you find and we'll keep looking if needs be.
Stephen "Highspeed" Kruse
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Stephen, The mill has been untouched since yesterday evening. Before I attempted anything, I jogged each axis to see what would happen. Everything worked in the positive and negative directions for each axis with the keyboard and via Mach for approximately fifteen times in each direction. Then I jogged again and the following were the results: Z+ worked, Z- no movement, Y+ and Y- moved toward Y- direction regardless of what key associated with Y axis was pressed, X- and X + moved to X- regardless of what key associated with X axis was pressed. Then I waited about ten minutes and it worked again in all directions for approximately ten times each. No further attempts to try anything. What do you make of the aforementioned? Any other suggestions to check? Thanks.
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Hmmmm, definitely something flakey. Could be a heat issue, either with the motors themselves or with the stepper drivers. You may need to see about putting some cooling fans on the drivers since we're getting into the hotter months of the year. They may have worked in the past, even during the hot months, but as they get older the heat could become more of an issue. And since they worked for a few cycles, then started going wonkey but worked again after letting them rest a while heat is definitely a likely culprit.
You said your drivers are enclosed, so is there sufficient ventilation on the enclosure? Is there a fan in that that may have stopped working?
Check to make sure your drivers are staying cool enough and then check your motors, too.
Let me know.
Highspeed
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The control box was purchased/made specifically for enclosing CNC components and has a CPU fan. I have been utilizing a wireless keyboard and mouse for approximately six months without any apparent problems. Also, have a wireless internet connection on the computer for updates of CNC based software. Can any of these potentially cause interference with drivers, etc. resulting in something like intermittent directional issues? Thanks.
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It is ALWAYS a good idea never to have network or wifi on the control pc, it can work but is a known source of all thats bad.
The control PC should only run the control program - Mach 3/4 etc and nothing else.
It would be worth trying a clean boot with networking turned off etc just to check
I have never tried a wifi keyboard but i cant see it being an issue - the interference would have to cause the exact signal as the Z down function needs and i think that would be pretty rare, more like it would just lose connection if interference was present.
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One thing I have noticed is that if the UC100 is off of the port slightly, motors will reverse directions sometimes out of the blue. Make sure there is a good connection between the UC100 and BOB. Try and eliminate any cable between the UC100 and BOB if possible.
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Something I saw in another thread is that the arrow keys for the X axis would run reverse on the first press, but release it and press again and the axis would move in the correct direction. Can you check and see if this is the case for you? I know you said this was all running until the cleaning, but if it's the wireless keyboard it could do strange things like this. (I don't think that other thread revealed any solution.)
Highspeed
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Yes, that is exactly what happens intermittently. It will move in the correct direction via the keyboard arrows, then not, and okay again. However, this also happens intermittently when using the jog arrows on Mach 3. The intermittent nature is the problem here. It would be alot easier to determine the problem area and course of action if it happened all the time as opposed to the 5th, 20th, etc. time. The motors and drivers are not getting hot. Any other suggestions? I certainly appreciate the help.
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one other thing to check is the motor cables. I have seen this ALOT. if you have the 4 pin plugs that have the locking screw on ring. The plugs have a molded KEY, so they cannot get plugged in wrong. WELL, that great except that they can be plugged in wrong. It will cause funky issues.
Check to make sure that everything is lined up.
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I turned off the wifi for the internet, replaced the wireless keyboard/mouse with wired versions, and checked the motor cables. I jogged in all directions approximately 20 times and it ran correctly, so thought it was fixed. However, ran it a few times and it started having directional problems once again. Then it worked correctly again. Essentially, have a unreliable/unusable mill at this point. Any other suggestions? Could uninstall and reinstall of Mach 3 possibly help?
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I used a multimeter to check directional pins on BOB. Also, checked 5V on the BOB and it indicated 2.82
Operating correctly:
(Z) 2.84, .56
(Y) 2.82, .88
(X) 2.62, .92
Here is what I got when Z+ worked, Z- no movement, Y+ and Y- moved toward Y- direction regardless of what key associated with Y axis was pressed, X- and X + moved to X- regardless of what key associated with X axis was pressed.
(Z) 2.63, .88
(Y) 2.63, .92
(X) 2.32, .92
When it isn't working correctly the malfunction is always the same as indicated above which may mean something. What is your take on the numbers? What else to check?
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I used a multimeter to check directional pins on BOB. Also, checked 5V on the BOB and it indicated 2.82
If you are using 5 volts to supply the breakout board then it should read 5 volts not 2.82.
Disconnect the supply to each of the driver's pul+ one at a time and see if the BoB voltage rises to +5 volts - if so then there is a fault with that particular driver.
If no fault is found then perhaps replace your 5 volt power source and see if this cures the problem.
Tweakie.
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When you checked 5v on the BOB, was it at the point the PSU was connected?
I would disconnect the PSU and check again, if this is one of the cheap silver PSUs, they are usually adjustable by a couple of volts, but don't adjust when connected to the BOB;)
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"Disconnect the supply to each of the driver's pul+ one at a time and see if the BoB voltage rises to +5 volts."
I did this and there was no change in the volts for the 3 drivers. I put the multimeter on the power supply 5V connection to see what it is showing and again checked the 5V connection on the BOB. They both showed 1.15. The following is the model of my power supply, but cosmetically mine looks different than what is pictured. http://www.automationtechnologiesinc.com/products-page/switching-power-supply/48v12-5a I also checked the 12V connection on the power supply that is connected to the case fan and it showed around 12V. There are 2 wires coming from the 5V of the power supply consisting of one to the 5V on the BOB and the other connected to one of the driver's PUL+. Do I have to replace this type of power supply entirely, or just disconnect the 5V wires and add another 5V power supply? Something like http://www.automationtechnologiesinc.com/products-page/switching-power-supply/kl-10-5-5v2a Thanks.
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I'd start by disconnecting everything from the power supply and checking the voltage being put out with no load. If it reads 5V, then most likely there is something else loading it down although it could be an adjustment in the power supply. I see it is a switching power supply and these usually have an output voltage adjustment. This adjustment can be thrown off, though, if the current draw is too high. Try checking the no load voltage and then add in components one at a time (I'd start with the breakout board) and see if you can determine a specific component that causes this drop in voltage.
Now if the no load voltage reading is also low, then it is most likely a bad power supply. You _could_ run two different power supplies, but then you may get into some weird situations of ground loops or even worse - different ground reference altogether. I'd really recommend replacing the one power supply and keep it simpler that way.
Stephen "Highspeed" Kruse
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It indicated low voltage with no load, so I will replace the power supply. The power supply is approximately 2 years old with not a lot of hours of usage, and cost around $110. Would you suggest to go that route again, or an alternative setup? Also, what is the likelihood that a power supply issue would be the cause of the direction problems that I outlined in prior posts? Thanks for all of the help.
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Also, what is the likelihood that a power supply issue would be the cause of the direction problems that I outlined in prior posts?
I would say it is almost certain that the bad power supply is the cause of the direction problems ;)
Tweakie.
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That sounds expensive for a psu ??
What size - voltage and current is it meant to be ?
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The psu came installed in a prewired control box. I priced the individual components that were recommended on various forums, and it was roughly the same to wire myself in-comparison to a prewired control box. Also, I lack the electronic expertise to tackle such a project. The following link outlines the components in my setup. http://www.automationtechnologiesinc.com/products-page/g0704-kit/3-axis-cnc-stepper-control-box I am questioning the overall quality of the psu, since it has lasted only two years with minimal usage.
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So its just the 5v psu thats failed?
I should think just about any 5v switch-mode psu would work, the BOB only draws minimal current and a 2A unit here in the UK would be about £10
I have not checked all the details of your unit though so please take my advice carefully ;)