Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: JEEPLESS on February 20, 2009, 12:16:16 PM
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Hello all.
I am in the process of converting a DOS based CNC Crafter 1914 over to Mach 3 and am using the Campbell Designs Combo board. I can see that Mach 3 is operating with the combo board (I see the step and direction LEDS change with jog state). The limit switches also trigger the combo board and Mach 3. Motor outputs are set as follows:
X STEP: PIN 2
X DIR: PIN 6
Y STEP: PIN 3
Y DIR: PIN 7
Z STEP: PIN 4
Z DIR: PIN 8
The motors are Applied Motion Products 5034-349 and the drivers are Applied Motion Products 7080. The drivers do operate the motors in test mode. Any help is appreciated. Thank you in advance.
Matt
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Do the motors lock? Does that board require an Enable?
Hood
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Hello Hood,
I don't think the combo board requires enable. However the DOS setup had the enable on the drivers wired (+5VDC on the high side and the low side went to the emegerency stop).
What do you mean by locking the motors? Is that an "enable" function?
Thank you.
Matt
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Ok it was the drive boards I was meaning, sorry should have been more specific. Do you have them enabled?
What I am meaning is are the motors locked or can you rotate them by hand? If they are locked then the drives must be enabled, if you can rotate then they are not.
Hood
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Hood-
With the power off, I can rotate the motors by hand (it's difficult). With the power on, I can not rotate them.
Matt
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Sounds like the drives are enabled then, check you have the correct pins asigned for the actual position you have the motors connected to.
Do you get any sound at all out of the motors when you try to jog? Do you see the DROs in Mach moving when you Jog?
Hood
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No sound at all from the motors when jogging. I do see the DROs moving in Mach. I have the pins configured per the combo board's instructions. Do I need to check elsewhere?
Matt
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No, if you have them connected as per the board and set up as per the board in Mach then that side of things should be ok. If you have a voltmeter you could check to see if the Step and Dir signals are being output from the combo board while you are jogging each axis in turn.
Hood
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I have 5VDC at the combo board when I jog.
Matt
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You should have 5v at the Dir output when you jog one way and 0v when you jog the other. If its a digital Voltmeter you will not see 5v on the Step output when jogging but you should see a voltage when you jog and 0v when you stop. The faster the jog the higher the voltage but also it will depend on your meter but in any case its not really important as long as you see the above.
If you do see that then the problem is from your connections between drive/combo or drive/motors.
Hood
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I do see the drop to 0V (.1) when I jog the other way. Is there an advantage to running the system w/ enabled drivers? The manual for the drivers says they do not need to be enabled. I was trying not to change too much of the original wiring, but I don't have a problem doing so if needed.
I will trace the 5VDC to the drivers. I suspect that it is the wiring between the combo board and the drivers - the motors will operate when the drivers are set to test mode (1/2 turn each direction).
Would motor tuning have any effect at this point? I figured that if I have no reaction from the motors at all, they are not getting the signal.
Thanks again for your help.
Matt
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Hood,
Here is a down and dirty drawing of my wiring. LPT-1 pin 1 and 14 are limit switches. LPT-2 pins 1 and 14, and pins 16 and 17 are the other sets of limit switches.
Matt
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Looks ok but would have to read the combo manual.
Hood
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What voltage is the drives Step and Dir power and where are you getting it from?
Hood
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Should be 5VDC as well. It is coming off the CNC Crafter power supply that is original to the system. That supply line should be fine, as it has not changed and the test mode of the drivers functions correctly.
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Yes I have no doubt that it is fine but I am thinking it will not be referenced to your step and direction signals, usually you take the power from the breakout.
Hood
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Hood,
That appears to be the problem. I tested on one of the drives and it appears to function properly.
Thank you for your help and patience. I may need some further help tuning motors . . . I'll let you know.
Thanks again,
Matt
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:)
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Hey Hood,
Between you and Ray L., there's some very good reading right here! No doubt about it - good information! And you make it seem easy!!!
Bill C.
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Professor Hood - ;)
I have spent some time trying to get the motors tuned up and am having problems calibrating the system. I have tried both calculating steps per unit and using the automatic setup in Mach 3. I set inches as my native unit. When I have the X axis move 1 unit it only moves 9/16". I click OK and have Mach 3 adjust the steps and repeat the process getting the same result. All three axis respond the same.
I went to motor tuning and put in a value of 10000. I then went to the MDI set the DRO for X axis to 0 and entered G0 X10. The axis moves 1 - 9/16".
My Applied Motion drivers are set for a 2000 S/R resolution. The resolution of my stepper motors is 200.
Thanks again,
Matt
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What pitch ballscrews do you have? Do you have any gearing between motor and ballscrews?
Hood
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Hood,
Best I can tell the screws are 11 tpi (p=.0909). Motors are direct coupled to these screws.
Matt
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Thats a weird one LOL, anyway at 11tpi that means you need to turn the motor 11 times to move one inch so 11 x 2000 = 22,000 steps per inch for motor tuning.
Hood
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Well, that's an improvement - but not there yet. With 22,000 steps per inch G0 X10 moves X 5 - 7/16".
Weird one - if you only knew what else goes on around here. LOL
Maybe I'm missing the obvious, is there a trick to calculating threads per inch?
Matt
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count them :)
Are they ballscrews? If so then get a rule or better a set of calipers and count how many there are to one inch.
Kind of sounds like your motors may be 9 degree steppers and that your screws could be 10TPI. Try setting to 40,000 in motor tuning.
Hood
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Count them - there's the problem . . . I'm a musician, I have trouble past 4. ;D
At 40,000 G0 X10 gets me 8 - 1/4". TPI is 10. Based on your previous remarks, that must be a more standard tpi. :)
Matt
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Something strange going on there, with your previous setting of 22,000 and moving 5.4375inches then setting the steps per to 40,000 you should have been 9.886inches.
Wonder if your problem is you are commanding a 10inch move, maybe you need to just stick below 4 ;D
Seriously though it may be you are losing steps, do a G1X10F10 and see how far it moves.
Hood
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The X axis seems happy at 64,000. Not so for Y. I'll try G1X10F10 in the morning.
Matt
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All axis are happy at 64000. I am going to try some test runs to check accuracy.
At 64K G1 X10 F10 moves X 10"
-Matt
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Something just doesnt add up but as long as you have things moving accurately then thats all that matters :)
Hood