Hello Guest it is July 18, 2019, 10:17:41 PM

Author Topic: Control crash, CNC router?  (Read 7766 times)

0 Members and 1 Guest are viewing this topic.

Offline c30232

*
  •  122 122
    • View Profile
Re: Control crash, CNC router?
« Reply #20 on: February 14, 2014, 10:50:09 AM »
It seems 066 is the current version. Where do I find 0.062?

I considered the lower setting, but have not yet tested for that.   It is indeed a Chinese VFD and it is set in a lower range.  It was set at full tilt when I ran the 4 1/2 hour no crash run. 

However, as the problem exists right know, I reckon the VFD has nothing to do with it as the power to the VFD has been has completely disconnected.  It occurred to me today that the PC and Mach we are using is from another table that, as far as Mach goes, was running impressively well.  In its new assignment there are two changes that would certainly relate to Mach:

1) A single circuit home switch setup was added.

2) Setting of soft limits.

When the soft limits were set we began to have problems.  The machine would soft limit out when it was a mile away from the setting,  We didn't mess with it and set them as they are now.  That is, well off the table.

     
Re: Control crash, CNC router?
« Reply #21 on: February 14, 2014, 04:39:56 PM »
Sounds like a conflict with the new home switch and/or soft limits.

1) Are the native units (mm or inches) set correctly.   
2) Are the soft limits correct for the table size and movement direction?

It almost appears as though the machine home location isn't correct to the table size. What happens when the "Ref Home" command is issued?

Offline c30232

*
  •  122 122
    • View Profile
Re: Control crash, CNC router?
« Reply #22 on: February 14, 2014, 05:04:17 PM »
The machine is factory wired with three proximity switches on a single circuit.  The soft limits are currently set larger than the actual table. Upon the home command the following occurs:

1) Z homes up

2) X homes left or negative to zero

3) Y homes forward or negative to zero

The machine actually makes the move and visually returns to the same spot each time.  I have not gauged that landing.  However, out and back on several consecutive 98" Y movements the return lands + - .001".  Thus it seems to count correctly.

Zero,zero is the left forward corner.  X is 48"  and Y is 98".  The native units are set to inches and the g-code is generated by a Mach wizard.  The code is an easy read and there are no surprises in the crash position.

What would reset machine zero mid table?

Mach is set to auto zero.  The xml is posted in a previous thread.   
Re: Control crash, CNC router?
« Reply #23 on: February 14, 2014, 05:37:09 PM »
The major change was adding the home prox switch. Can you disable the prox switch... only using the soft limits and see if the problem is still present? Prox switches use a solid state device to either sink or source the output logic. The wrong type of prox (NPN or PNP) wired to a BOB can cause strange problems.

Generally the X direction is the longer and Y is shorter. Yours are reversed which isn't a problem if Mach is set up for that.

Offline c30232

*
  •  122 122
    • View Profile
Re: Control crash, CNC router?
« Reply #24 on: February 14, 2014, 06:13:08 PM »
The home was in place, I believe, before the 4 1/2 hour run.  However, I agree that the sprite of the issue resides somewhere in the home protocol.  It will be very easy to disconnect it and just as easy to live without.  I wondered about the NPN v PNP when we hooked it up.  It is something I don't have a good understanding of and the fact that it worked caused me to believe we got lucky.  I can't locate a diagram for the BOB and it is somewhat trial and error.

X is simply left to right and matches other stuff, some longer, some shorter.

I will take another stab at it in a few minutes.   
Re: Control crash, CNC router?
« Reply #25 on: February 14, 2014, 06:35:02 PM »
It seems 066 is the current version. Where do I find 0.062?

You can get previous versions from the ftp site.
ftp://machsupport.com/Mach/

Russ
Re: Control crash, CNC router?
« Reply #26 on: February 14, 2014, 07:36:31 PM »
Typical 8 & 12mm barrel type prox switches are normally open (NPN or voltage sinking) and can't be wired in series with other prox switches. This is a common mistake people make thinking there is a internal switch contact. Each switch has to have a separate input assigned in the BOB and Mach 3 configured as required.

The draw back with a NPN prox switch is there is no broken wire safety aspect. So if the switch fails or a wire falls off a terminal will result in a axis homing crash. Normally closed prox switches (PNP or voltage sourcing) are less common and usually much more expensive.

Offline c30232

*
  •  122 122
    • View Profile
Re: Control crash, CNC router?
« Reply #27 on: February 14, 2014, 08:21:20 PM »
Thanks,
You have correctly identified the switch.  I will disconnect them without making any other corrections and pretend it is the source of the problem.  We shall see.

The BOB is capable of individual home runs.  I agree it will be better but it will require a rewire of the machine.  I guess that will force us to examine the other wiring . . . not a bad idea.

The mystery to me is that the machine did run with all of its bad habits . . . maybe.  The person I got it from never saw it run.  Perhaps that is why it was for sale.  But, it is apparent that it did do some work in its day.  It's not beat, but it has some dirt under the fingernails.

   

Offline c30232

*
  •  122 122
    • View Profile
Re: Control crash, CNC router?
« Reply #28 on: February 14, 2014, 08:39:42 PM »
Geh,

We just completed a dry run with no issue.  It's now running the cycle with the router on but not in the cut.  While running, I tripped the proximity switches one by one and there was no response from the BOB or Mach.
Re: Control crash, CNC router?
« Reply #29 on: February 14, 2014, 11:34:36 PM »
I'm glad its been narrowed down.

I assume the prox switches are incorrectly wired in series which is why you didn't see a response from Mach or the BOB. Almost all prox switch have a LED indicator light mounted someplace on them, usually where the cable is attached, which is a great troubleshoot tool to test the function. Prox switches require 12-30 vdc supply voltage. Below 12 volts or over 30 volts can result in unpredictable or failure to operate.

While its possible to configure Mach... I've never been a fan of series wire mech limit switches unless the BOB doesn't have the inputs.