Messages

1

General Mach Discussion / Re: Motor changing direction at random

« on: January 13, 2021, 05:39:16 PM »

I will close this topic as the solution to the issue has been found and open another as required.
Thanks again.

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General Mach Discussion / Re: Motor changing direction at random

« on: January 13, 2021, 12:00:22 AM »

Aaah so I'm not finished yet, OK, I'll put the motors and gantries back together again to prepare for that.

What should I be looking at to tune the motors

3

General Mach Discussion / Re: Motor changing direction at random

« on: January 12, 2021, 08:49:31 PM »

Problem solved , the Y TB6600 B- terminal was not making contact with the motor cable so the motor was activated by one coil only.
Such a simple situation. I soldered the wire end and folded it back over the insulation, inserted it into the terminal receptacle and tightened the screw. The screw pushed against the insulation and pushed the wire into the plastic corner of the terminal, so no contact. The torsion on that wire was such that every time I took it out of the terminal receptacle and then put it back again, it would enter in the same position 

Gentlemen, thanks for all your help. I'll put the machine back together again and prepare for the next phase - learning how to make something.

Have a great 2021 with good health

4

General Mach Discussion / Re: Motor changing direction at random

« on: January 11, 2021, 05:20:47 AM »

Thanks TPS, the replacement PC was not functional, hard drive issues. I'm borrowing another tomorrow loaded with XP.

Did quite some diagnostics with the motors at rest; all within normal limits. Will have help tomorrow to measure current and voltage at the HC245, BOB and TB6600s, with the motors activated.

I have the Motor Output values entered as per the BOB manual and will measure the DIR values at both the BOB and TB6600s with the motors at rest and activated

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General Mach Discussion / Re: Motor changing direction at random

« on: January 10, 2021, 08:49:08 PM »

Yes, yesterday when I checked the DIR, direction also changes when the DIR is low. i.e. when activating the Y- command, the DIR voltage was low and remained low even though the motor changed direction. I will go through all of the diagnostics again though. Have just returned home after shopping and picking up the other CPU.

Can any one tell me in detail what the Mach3 and CPU software/hardware processes are between activating the jog command and the associated Voltage / current changes in the HC245 pins. There must be a number of settings and other variables within Mach3 and the CPU that have an effect; and that could conflict with each other. I must say that my understanding of what occurs within the software and CPU hardware is quite dim.

6

General Mach Discussion / Re: Motor changing direction at random

« on: January 10, 2021, 05:25:18 PM »

Question: what determines that a motor should run in one direction and not the other when an appropriate voltage is applied to it.

Also, if the DIR input voltage is close to zero both at rest and when the motor runs in a direction, what other factor determines that the motor should actually run and not be at rest.

7

General Mach Discussion / Re: Motor changing direction at random

« on: January 10, 2021, 04:47:05 PM »

Yes MN300, it did, but I will go through the entire diagnostics again today to double check all parameters.

Thanks for the utube TPS, viewed it and will do that too.

8

General Mach Discussion / Re: Motor changing direction at random

« on: January 10, 2021, 06:52:30 AM »

Yes, I can see how that could change the direction at random.

At rest though, the parallel port supplies the HC245 STEP Input with 4.5 V and the DIR Input with 108.6 mV. When the motors are activated the parallel port supplies the HC245 DIR Input with 4.5V in the positive direction and 108.6mV in the negative direction. Therefore the parallel port can supply the HC245 with more than 3.3V when it is required. So I now think it is a 5V parallel port. Also, the random direction changes only occur on the Y channel, which ever way it is hooked up between Mach3 and the Y motor.

There must be something I don't as yet see at the moment and maybe the anomaly is in the computer hardware, although the Y direction changes did not occur when the CNC was attached to the Maxpath42 circuitry .... that just blew up ..... I'll see tomorrow when I hook the other CPU up.

I did not test the voltage on the HC245 outputs with the motors running ... I'll do that tomorrow as well before I connect the other CPU

I have read blogs that state that although stepper coil wiring colour codes are specified by the manufacturer, sometimes the coils are wired differently, which, if not detected, can cause random direction changes. I have interchanged the motors though, and the random direction change always occurs to whatever motor is connected to the Y channel.

9

General Mach Discussion / Re: Motor changing direction at random

« on: January 10, 2021, 04:26:02 AM »

Hi ZASto, would you please explain that in layman's terms?

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General Mach Discussion / Re: Motor changing direction at random

« on: January 10, 2021, 12:39:49 AM »

Heisenberg would be thrilled