Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: cvk31 on March 27, 2011, 10:06:49 PM
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Hello All,
I purchased a Taig Mill about a year ago from a great guy back east that had it set up and running parts.
When I received it it came with all kinds of useful info as well as his Mach3 setup.xml so I plugged her in and was starting to make some parts when my computer took the worst kind of a ********* on me. It took me a little while to get it rebuilt which included a new motherboard. Work has been so busy the whole setup has sat in the shop for about the last eight months.
Needless to say getting it fired up again after all this time is like doing it for the first time. I have Mach3 with the custom setup file and everything seems to be back to square one except a for a weird issue with my Y stepper. Again, I had the whole setup working before the PC rebuild so I'm a little stumped.
When I jog the Y axis the stepper makes noise like it is trying to go but it doesn't move. If I tap the jog over and over it will take off at the correct speed and seems to operate normally, sometimes it'll even let me reverse direction. I switched the leads from the controller to the steppers and the problem is repeated in the x axis and y works fine so I am pretty sure by process of elimination that this isn't a problem with the stepper. I am using Keling KL23H276-30-BB steppers.
I do not know how to test this but the sound the stepper makes when it is " jammed up " sounds like it isn't getting enough power.
If I hold down the arrow key to jog it and give the wheel on the stepper a little twist it will usually take off too.
Any help would be greatly appreciated...
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I would be inclined to remove the stepper from its mountings and see if this problem persists under 'no load' conditions.
Tweakie.
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I had a similar problem to this, and it was the parallel lead from the comp to the machine that was at fault.
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I thought it might be the screw binding too so I remove the stepper from the mount and it behaved the same way. This was before I switched the leads and saw the same problem with the x stepper on the y lead.
I am a mechanical designer and don't know much about testing electronics. I own a decent multi tester but am unsure how to test the voltage of the wires to the stepper.
Can someone give me some bone head instructions?
Thanks for the help Tweakie and angel tech.
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check the gnd connections on the drives.
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Is the stepper making a screeching sound when it is not working ?
Tweakie.
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It's not screaching per say but it is definitely making noise. The sound is probably 50% as loud as if it were working properly.
How do I check the ground?
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Just a thought.
Go to config, ports and pins and put a check in the sherline 1/2 pulse mode box. Then try.
Tweakie.
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Tried that, no change.
Now that you mention it I thought that it was strange that the steppers are set at something like 32,800 steps?
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Is that steps per inch ?
If it's steps per mm then I think you need to retune your motors from scratch.
Tweakie.
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It's steps per inch. I also checked the x axis to see if an inch on the DRO's was an inch on the table and it was correct.
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Grasping at straws here now.
Have you tried changing the state of the step pin active high / active low in motor outputs ?
There is another issue which keeps causing problems mainly with new computers in that some parallel ports now output 3.3Volts TTL instead of the old standard 5Volts TTL. Some driver circuits / boards will not work reliably with 3.3Volt TTL and some will just not work at all.
If you have a voltmeter then it may be an idea to measure the voltage on a direction pin whilst jogging the axis in one direction then in the other. This voltage should be approx 5V in one direction and approx 0V in the other direction. The voltage on step pins cannot be measured in this way only the voltage on a direction pin.
If you find the voltage to be approx 3.3V this could explain why the setup worked OK with your old computer but now does not work well.
The easiest solution would be to fit a PCI parallel port card (assuming you have a free PCI slot) which does output the full 5Volts TTL signals.
Tweakie.
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Man, I really appreciate your input here Tweakie, I did try changing the active high/low. Are all those settings contained in the .xml file? If they are and it worked correctly before I rebuilt the computer... I am now wondering if maybe the controller got damaged or something? I moved it around a few times while remodeling my garage.
Or...
Is it possible the bios settings are different now? I went in and changed the bios setting for the parallel port from EES? to the recommended setting I found online which was ECP/EEC or something like that. Sorry, I am at work right now cant actually look at the settings. Anyway, when I changed the setting there was a huge delay between key commands and movement of the motors and the stepper behaved the same way so I changed it back. There were like four options for that setting in the bios.
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The printer port LPT should be set to ECP.
I updated my earlier post to add more info.
Tweakie.
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Cool,
I'll check tha whenI get home. I don't really know which wires to check though. Do you have a schematic that shows which pins to check? Would I be able to check that output voltage on the manufacturers literature for the Motherboard?
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So, I checked the pins with the multi tester...
With the probes in pins 1 and 5 the voltage jumps up to 8.9v and stays there when I let off the up arrow when I press the down arrow the voltage drops to zero.
With the probes in pins 1 and 4 the voltage reads 3.7 when pressing the up arrow and returns to zero when I let off of the key, works the same way when I press the down arrow.
This is with the Sherline 1/2 Pulse option selected. Without it selected I get zero on pins 1 and 4 when pressing keys.
Oh, now the x axis is behaving the same way.
Z still works.
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When measuring the port pins - pins 18 to 25 are ground so the multimeter negative lead should be connected to one of these pins then the positive lead to a direction pin (generally from the group pins 2 to 9)
Don't know if this helps.
Tweakie.
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Ok, I'll try that.
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That was the problem, thanks for all the help. I'm going to install a new pci parallel card as I have a couple of open slots.
Hopefully, I'll be good to go soon.
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I will keep my fingers crossed for you. ;D
Tweakie.
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So, the greasy pack rat expert 30 miles from my house told me "oh yeah, I have it right here" I drove down there picked up the parallel pci card I needed, came home got her plugged in and talking and I've got the same problem!
Only now I'm getting 2.6v instead of 3.3?
I've read people found the right pci card by trial and error necause none of these chinese manufacturers post the voltage specs.
If anyone can tell me what they found and from who it would be greatly appreciated.
Side Note: Why does the assigned dir pin in Mach say 2 when I am actually getting the dir signal from pin 3?
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I'm still trying to understand these outputs and I just checked the Z axis dir voltage because it is the only axis that will move and the voltage read 1.4!?
Why does this axis work at a lower voltage than the others that do not work?
I have a xylotex controller btw. Can I adjust the input level on the breakout board somehow?
I may be way out in left field thinking the controller has anything to do with it at all.
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cvk31,
Check with them first but I think that the A25 PCI parallel port card sold by CNC4PC is OK for 5Volts output.
Tweakie.
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I picked up a card this afternoon which was verified by the guy at the shop to run 5v brought it home tested it, 5v!... Still having the same problem.
I am running licensed version of R3.043. Anyone? What am I missing? Anyone?
The Z stepper runs normally, the Y stepper wines but does not move and X makes no sounds no movement.
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Can you attach your xml. Also not sure if you have said but what kind of drives are you using?
Hood
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Keling 23h276 steppers, What's driving me nuts is everything worked before the PC rebuild.
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xml looks ok.
I was meaning the drives that the motor connects to, also do you have a breakout board?
Hood
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Sorry, I call gearmotors drives in my trade :) Its a Xylotex xs-3525.
http://www.xylotex.com/XS3525V400.pdf
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Ok, How do I test each axis on the controller? X and Z work great. Y just makes noise and wont move?
I need a literal how to as I'm not to sharp when it comes to the multi tester.
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It's the controller.
Reassigned pins to A axis and my x works. Will be sending this board out for repair.
Thanks for the help guys.
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Because I am now using the A axis in the controller to drive Y the motor runs the wrong direction when I press the key to move it. I know this can be fixed in motor tuning by switching the hi/lo configuration but it is giving me headaches while setting up my soft limits. Can someone tell me which wires to switch at the terminal in my controller box so I do not have tio use the software to correct this problem?
I am running Keling steppers, there are 8 wires coming from the stepper which are combined into 4 wires going to the controller.
Here is a wiring schematic for the Keling, looks like ancient egyption ???
http://www.kelinginc.net/KL23H276-30-8B.pdf
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Figured it out.