Does wiring for limit switches need to be shielded?
Hey G'day,
Does the wiring for limit switches need to be shielded,
I'm getting some strange behavior reset button will randomly enable.
Unable to switch it off. Even using override not helping. I then disable limit switch/re enable good for a while.
My limit switches will not work in series for whatever reason, each switch wired separately functions ok.
There are no breaks in the wiring all seems good.
If I use some test wire all switches test ok, doing homing routine axis by axis function ok.
If I use the wires through the cnc loom, Y (I have a slave) the homing is interesting to say the least. One side seems to advance quicker than the other or at moments move in opposite directions to each other its a ballet dance.
Breaking out the test wires the switch functions ok and the homing sequence is ok.
Cheers,
Steve
Re: Does wiring for limit switches need to be shielded?
It does seem that you are picking up some electrical noise. Are you using your switches Normally Closed? That is normally reasonably noise immune, and also if a wire breaks it looks like an activated switch. It's possible that you need to shield the motor cables or at least separate the power and signal cables as much as possible. If needed, then shield the limit switch cables.
Re: Does wiring for limit switches need to be shielded?
Most of the causes of what you ate experiencing I have found to be lack of proper earth bonding and grounding of power commons etc to a star ground, that includes the service ground .
Al.
Re: Does wiring for limit switches need to be shielded?
Quote:
Originally Posted by
Jim Dawson
It does seem that you are picking up some electrical noise. Are you using your switches Normally Closed? That is normally reasonably noise immune, and also if a wire breaks it looks like an activated switch. It's possible that you need to shield the motor cables or at least separate the power and signal cables as much as possible. If needed, then shield the limit switch cables.
Hey Jim G'day,
Thank you for the reply,
Yes all the switches are normally closed. All the motors have shielded cables.
I guess I will bite the bullet and rewire again. My assumption (obviously wrong) was if using Normally Closed switches it wouldn't matter.
Laughing gently atm, my mate just called with a similar dropout issue, whenever he turns his spindle on his laptop drops connection to UCCNC. His issue was easy to fix, he doesn't like using the touch pad so he keeps attaching a wireless mouse, Every time he adds the mouse hes in trouble lol.
He unfortunately doesnt have a solution for me. Ok back to the garage see if I have any more shielded cable left.
Cheers,
Steve
Maybe I should try normally open and see if that doesn't improve things.
Re: Does wiring for limit switches need to be shielded?
Quote:
Originally Posted by
curiosity22
Hey Jim G'day,
Thank you for the reply, .......
Maybe I should try normally open and see if that doesn't improve things.
My pleasure.
At this point anything is worth a try.
Re: Does wiring for limit switches need to be shielded?
Quote:
Originally Posted by
Al_The_Man
Most of the causes of what you ate experiencing I have found to be lack of proper earth bonding and grounding of power commons etc to a star ground, that includes the service ground .
Al.
I believe everything is well grounded but a valuable point to check. Thank you for the input I will look at that as well to make sure..
Re: Does wiring for limit switches need to be shielded?
You can use the debounce filter of the UCCNC to filter out noise on your limit switch inputs.
You can set a few milliseconds and then those short noise spikes will be ignored by the controller.
1 Attachment(s)
Re: Does wiring for limit switches need to be shielded?
Quote:
Originally Posted by
curiosity22
Hey G'day,
Does the wiring for limit switches need to be shielded,
I'm getting some strange behavior reset button will randomly enable.
Unable to switch it off. Even using override not helping. I then disable limit switch/re enable good for a while.
My limit switches will not work in series for whatever reason, each switch wired separately functions ok.
There are no breaks in the wiring all seems good.
If I use some test wire all switches test ok, doing homing routine axis by axis function ok.
If I use the wires through the cnc loom, Y (I have a slave) the homing is interesting to say the least. One side seems to advance quicker than the other or at moments move in opposite directions to each other its a ballet dance.
Breaking out the test wires the switch functions ok and the homing sequence is ok.
Cheers,
Steve
Your best choice is to add a EMI Power Filter on the input power to the VFD Drive and most of these problems will despair Here is the Filter spec's you will need it looks big in the photo but it is quite small
TDK Lambda EMI RSEN-2030L Power Filter this needs to be mounted close to the input Power to the VFD Drive
Re: Does wiring for limit switches need to be shielded?
Quote:
Originally Posted by
OlfCNC
You can use the debounce filter of the UCCNC to filter out noise on your limit switch inputs.
You can set a few milliseconds and then those short noise spikes will be ignored by the controller.
Band-aids are not a way to fix something like this
Re: Does wiring for limit switches need to be shielded?
Quote:
Originally Posted by
mactec54
Band-aids are not a way to fix something like this
It is done like that in the industry. You cannot always get rid of all the noise in industrial environments.
Re: Does wiring for limit switches need to be shielded?
Quote:
Originally Posted by
OlfCNC
It is done like that in the industry. You cannot always get rid of all the noise in industrial environments.
Yes you can if you know what you are doing Hobby or Industrial makes no difference
Re: Does wiring for limit switches need to be shielded?
Hobby and industrial actually makes a huge difference. In a hobby environment you usually working in a garage with not many powerful machinery working around your little hobby machine.
In industrial environments there are usually welding machines, plasmacutters, large lathes and mills switching tens and hundreds of ampers around causing lots of EMI.
Which can cause noise issues to your little hobby machine in that noisy industrial environment.
Re: Does wiring for limit switches need to be shielded?
Quote:
Originally Posted by
OlfCNC
Hobby and industrial actually makes a huge difference. In a hobby environment you usually working in a garage with not many powerful machinery working around your little hobby machine.
In industrial environments there are usually welding machines, plasmacutters, large lathes and mills switching tens and hundreds of ampers around causing lots of EMI.
Which can cause noise issues to your little hobby machine in that noisy industrial environment.
You live in a country that has EMI noise restrictions and all industries have to be compliant required by code, there should not be any difference in both environments if there is then you are not code compliant
Just learn how to wire your machines so there is no interference that can change the way it runs it's very easy to do, even in the industry with any amount of amps being switched should not affect any other machine on the same Mains supply, Noise is easy to fix if you know how and what to look for
Re: Does wiring for limit switches need to be shielded?
Seems to me that you have never worked in the industry. I live in Sweden where everything is regulated but noise does not care about the regulations. :)
Re: Does wiring for limit switches need to be shielded?
I agree with what mac said...a filter is important, it will not filter out everything but it is something you will need anyway. There are lots of other things that could be causing your issues. A pic of your layout/wiring would help :)
5 Attachment(s)
Re: Does wiring for limit switches need to be shielded?
Quote:
Originally Posted by
OlfCNC
Seems to me that you have never worked in the industry. I live in Sweden where everything is regulated but noise does not care about the regulations. :)
You don't have a EMI noise problem if the whole electrical system is compliant that is what the regulations are for in your country which I already said :)
As for not working in the industry have been in the industry my whole life, I have my own Industrial machine shop as well, and other industrial property that I own in more than one country, even my Home workshop is up to industrial standards on a smaller scale which has Machining centers Mills and Lathes Surface Grinder Injection molding and fabrication and all types of welding I never have a noise problem on my 400Amp residential Home Power supply
An unusual snow fall we had showing part of my Homes 1.5 acres
Just some snips of my Home shop there is much more but I'm not one to brag enjoy :)
Re: Does wiring for limit switches need to be shielded?
The issue is that even in a country where everything like EMI emission is regulated people often do not care.
You just start using a cheap chinese welding or plasma equipment and you can get noise issues.
Like in this case the OP started using a chinese VFD and he is having noise problems.
A quick fix could be to use the debounce filter in the UCCNC, but ofcourse filtering the noise is the best solution, just sometimes it is not easy.
Re: Does wiring for limit switches need to be shielded?
Quote:
Originally Posted by
OlfCNC
The issue is that even in a country where everything like EMI emission is regulated people often do not care.
You just start using a cheap chinese welding or plasma equipment and you can get noise issues.
Like in this case the OP started using a chinese VFD and he is having noise problems.
A quick fix could be to use the debounce filter in the UCCNC, but ofcourse filtering the noise is the best solution, just sometimes it is not easy.
Using debounce has trade off and is just a band-aids for a real problem it does not matter what equipment you use or where it is from cheap or expensive correct wiring practices solve all these problems
Re: Does wiring for limit switches need to be shielded?
Quote:
Originally Posted by
OlfCNC
You can use the debounce filter of the UCCNC to filter out noise on your limit switch inputs.
You can set a few milliseconds and then those short noise spikes will be ignored by the controller.
Hey Olf thank you for the suggestion, Ill have to pencil that down and find out where it is in the menus.
Cheers,
Steve
Re: Does wiring for limit switches need to be shielded?
Cheers for that mate,
Not to expensive to buy and having one won't hurt.
Cheers,
Steve