Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: Aegir on December 22, 2015, 03:48:06 AM

Title: Limit switch help
Post by: Aegir on December 22, 2015, 03:48:06 AM
OK, so I know there has been threads on this, I have read them. It didn't help me though, as I tried the easy stuff mentioned but not sure what the rest meant.
My machine is a Wabeco 1410 LF running Mach 3 and MDA Precision supplied the control unit on the machine.
I have never had any issues over the 2 years I have owned it, and it has had very little use. A few times it has stopped and gave a Stepper motor error, but that has happened only a few times and not for the last 6 months.

So currently I can machine nothing, as when I try to run a file, it trips on the Y axis and says ''limit switch triggered'' and the next line says ''E stop requested''    It also does this at start up, and never said that before.
I can jog the machine using the key board without issue and never had this error before at all.   

So in the other threads it has been mentioned ''noise'' can likely be the issue. OK, well I confess I am lost there.
I have checked the debounce settings that were mentioned and mine was extremely high as it is, way higher than suggestions given. I changed it to about 5 different settings anyway and no luck.
So next people are talking about ceramic caps and noise shielding, but I have no idea what is meant by this.
Since it worked fine for 2 years in the same location , surely there must be any easy fix that does not require a degree in electronics?

Help, please  
Title: Re: Limit switch help
Post by: olf20 on December 22, 2015, 07:39:47 AM
By your debounce setting being set to a high number
means that there is some noise present from the factory.

Need to check your limit switch on Y. It could be faulty.
But most likely it is noise on you signal lines.
The wire from the limit switches needs to be shielded
cable. If they are then the shield wire should only be
hooked to a clean ground (cabinet ground) on one end
only.
If the wiring is not shielded then you will fight a losing
battle.
Have any wires been move or relocated?
Have you added something electrical in your
shop that might generate electrical noise??
This can be hard to track down sometimes.
I'm sure others will chime in and offer other
ideas.
olf20 / Bob
Title: Re: Limit switch help
Post by: Aegir on December 22, 2015, 08:39:49 AM
Nothing new in the shop, the lathe is unplugged too.
I have no idea about what is where, but here is a picture of the set up when I take off the back of the control box.  The debounce was set to 20000 from the factory, and in another thread I noticed ''Hood'' had told someone 10000 was too high as well, so 20000 is way over. Having said that, it has up until now worked fine. Also in the diagnostic window shows no faults on anything. 
(http://i789.photobucket.com/albums/yy175/t20569cald/20151222_1806161_zpsln61udbn.jpg)
 
Title: Re: Limit switch help
Post by: BR549 on December 22, 2015, 10:56:00 AM
It could be a bad wire,bad switch,noise OR a currupt XML file.   Check your Switch circuit in mach3, Press the switch and see IF the proper LED lights up on the diagnostics page. IF it does it it not teh circuit .  IF the light is already lit then it may be the XML file. Reload your  good XML backup file. You do have one right??

It also could be a bad PIN on the board or teh supply cable.


IF it is neither of those then look for noise.

(;-) TP
Title: Re: Limit switch help
Post by: Aegir on December 23, 2015, 08:13:46 AM
It could be a bad wire,bad switch,noise OR a currupt XML file.   Check your Switch circuit in mach3, Press the switch and see IF the proper LED lights up on the diagnostics page. IF it does it it not teh circuit .  IF the light is already lit then it may be the XML file. Reload your  good XML backup file. You do have one right??

It also could be a bad PIN on the board or teh supply cable.


IF it is neither of those then look for noise.

(;-) TP

A back up of XML,,,,,, arh no, didn't know of such a thing to be honest. I am fairly new, as you may have gathered.
Title: Re: Limit switch help
Post by: Aegir on December 24, 2015, 10:17:49 PM
It could be a bad wire,bad switch,noise OR a currupt XML file.   Check your Switch circuit in mach3, Press the switch and see IF the proper LED lights up on the diagnostics page. IF it does it it not teh circuit .  IF the light is already lit then it may be the XML file. Reload your  good XML backup file. You do have one right??

It also could be a bad PIN on the board or teh supply cable.


IF it is neither of those then look for noise.

(;-) TP
No lights are lit on the diagnostics page, and I am not sure which switch or where it is to press for the test.
I do not have a backup of the XML, however MDA Precision will , so I have mentioned that to them, and now I have learnt where that is, and what it is.
So this issue like all others is a good learning experience, even though a little frustrating.