Smoothieboard communication errors - [SOLVED]

All my cuts starts with M106 for turning on Air-Assist & Fumes Extractor.
I noticed my smoothie homes and print this to the console. this should not happen.
What you see is me sending M106 and M107 macros manually. same happens when i stream a job. in this case I need to restart the job (click START again) and since M106 is still on job starts without homing - as it should.
please advice.

What you see below is me sending M106 and M107 macros manually. same happens when i stream a job.

Starting stream
Stream completed in 0:00
WARNING: This is not a sanctioned board and may be unreliable and even dangerous. This MCU is deprecated, and cannot guarantee proper function
G28.2 XY
Starting stream
Stream completed in 0:00

This is the same issue you are having with the file in your other post. It is electrical noise interference from the relay clicking on that is resetting the comms and causing the Smoothieboard to reset. You need to find the emi gremlins that are lurking in your installation to solve both problems :slight_smile:

I have checked with both assist and extractor disconnected from mains. same. i will now disconnect the relay from smoothie (it’s a SSR) and check again. tomorrow i will conduct more power tests.

1 Like

I have narrowed it down - Air pump is the culprit.
no matter what i try, - moving it away, shielding it, grounding it, - nothing works. when Air pump is connected to my external SSR which in turns is pushed by Smoothie fet - Laser homes.

A small progress…
I have no idea why a 220VAC pump is effecting smoothie when it is connected to an external DC SSR which is connected to Smoothie’s 24V fet (bed-heater fet). I will conduct more tests tomorrow.


More progress,
I unplugged the pump from the SSR and manually turned it ON and OFF from an uncontrolled mains and still - laser homes each time i powered it on. My next move was disconnecting the USB going to my PC and manually using the LCD screen i hooked up directly to Smoothie and sent M106 and M107 and lo and behold - no issues.

So, even though my apartment has only single phase I suspect that having the PC and my Laser in different rooms powered by a different mains socket is the culprit, most probably ground loop or whatever. i am very curious to connected my PC to my Laser system same socket but before i do so i want to measure volts and resistance between these two sockets and then share same socket

i really hope I found my emi gremlins and this will lead to solving my problems.

1 Like

Glad you at least narrowed it down to the offending device. Now fixing the issue is the next big hurdle to tackle.

Thanks for helping me out.
I will continue tomorrow and keep you posted.

Stay tuned :slight_smile:

It might be that the board isn’t properly grounded in the K40, and it’s grounding through the USB on the PC. I’ve seen that happen before.

It gets its power (and ground) directly from LPSU 24V plug. i want to believe the LPSU is well grounded to chassis. from my past experience in some cases floating ground is better than shared ground and in other cases shared ground is better. go figure. I will check that as well.

1 Like

To my complete amazement and following me testing many aspects of this issue of mine, i found out for the first time ever that the physical metallic shield of the USB plug , not the minus power line in it, is not grounded. however, checking connectivity between the USB ports shields on the PC itself and outlet power - they seem to be grounded. So what i did was checking the same on laser side and - same. Smnoothie USB plug’s shield is floating. To add to the confusion, I then grounded the shield of Smoothie USB plug (to Laser chassis which is grounded) to earth and now M106 do not reset my board.

The more i learn as i go, the more puzzled I am.

1 Like

Oz, Please elaborate.
Are you saying from your experience, that in this case you mentioned there is a need to ground the USB shielding itself? cause it looks like it is floating - the wire shielding itself is not connected to main 24V DC Minus terminal. I am not sure if what i’m doing is right, but the fact that I have grounded the USB extension cable’s shield ON BOTH ENDs of it made the change. i am still checking things out but you can’t argue with the statistics:

  • When USB shield is floating - Smoothie resets when Pump starts
  • When USB shield is grounded - Smoothie does not get reset when Pump starts

It looks like Pump is somehow generating emi that rides on the long usb extension cable shield (which if not grounded radiates onto the communication lines) , gets amplified and effects communication lines.

This seems to (crossing fingers…) do the trick.
as a temporary solutions until i find the time to move the entire system to my living room for more appropriate fix. using a dremel i striped the plastic off the short cable that connects to smoothie and grounded the shield to earth. this means that now the USB extension cable is grounded all the way from PC to Laser and is not floating anymore.

On the left is my 10m active usb extension cable, on the right is the now grounded shielded usb cord connected to smoothie.

1 Like

This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.