Interference

[VCParticipant @vc44480]

Hi All

I have a problem with my Gerbil controlled router

I have two transformers one 24 volt to run the steppers

and the second one 100 volt to run the spindle motor

every thing works fine without the spindle motor connected

but once this is connected I get a error and the program

shuts down, I can run the spindle from the 24 volt but  as

you can imagine very slow

Any help would be great

Thanks Vernon

[mike TParticipant @miket56243]

Hello Vernon,

When you say you have a 24volt and a 100volt transformer, do you actually mean you have two DC power supply units (PSUs) i.e. 24 volt DC and 100 volt DC.

I would carefully check the two PSU cases are connected to earth.

Mike

[BazyleParticipant @bazyle]

We must assume you are not somehow switching the motor on using the GRBL controller but doing it manually. Remove the spindle motor from the machine so it is not able to make connection through its body.
Try to run and see if the fault persists. If it does the problem is mains conducted noise from crappy cheap supplies.
If it is ok while running move the motor to touch the machine frame, of use a jumper wire. If that kills it you have an earth problem. You might get away with wrapping the motor in film to insulate it.

You might still upset things when you try to use a z-probe and connect it to the spindle.

[Robert Atkinson 2Participant @robertatkinson2]

I’m afraid your description is too vauge to provide advice. As a minimum the make(s) and models of the “transformers” (almost certainly DC power supplies) and spindle motor.
When you say it fails when the spindle motor is “connected” do you mean running or literally if connected? How are you turning the spindle motor on and off?
Mike and Bazyle’s comments are pertenent but a better description of the situation is required. A photo or photos of the machine might help too.

Robert.

[jaCK HobsonParticipant @jackhobson50760]

You might have other power supplies as well – to the computer gubbinz? I had trouble running my 3D printer from a raspberry pi until I powered the pi via the printer power supply instead of direct from mains.

[SillyOldDufferModerator @sillyoldduffer]

I agree – more information about the setup please.   A circuit diagram and photos would help.

No proof but I suspect the computer running GRBL is being confused by electrical noise generated by the 100V spindle motor and it’s power supply.   I’d look for ways in the two are coupled together: shared power supply, cables neatly bundled together in a loom, long wires leading to the GRBL’s input/outputs.

These days one or more of the power supplies are likely to be switched mode rather than transformer based.  Switched mode units are lighter, cheaper and more efficient than transformer supplies,  but they work by generating sharp radio frequency pulses.  Cross-coupling occurs in ordinary power cables because these behave like inductors and capacitors at RF.

Ideally the input and outputs of are a switch mode power supply are carefully filtered.  Sadly, filtering is expensive, so it may be missing or inadequate on a cheap unit.   The answer may be a better made power supply.

But before that, work through the wiring:

• Don’t run signal wires parallel with power lines.
• Keep wires as short as possible.
• As the 100V supply is suspect, try reducing coupling by routing it away from all other cables.
• Earth all the wires in the electronics to a common point.  (NB.  This is a signal earth in addition to the safety earth, not instead of.   The purpose of a common signal earth is to prevent RF earth loops, because these cause cross-coupling.)

If none of that doesn’t work there’s a lot more that can be done, but it gets complicated.  Providing more info allows attention to be focussed on likely causes, rather than expensive guess work.

Dave

 

[John HaineParticipant @johnhaine32865]

Jack: “I had trouble running my 3D printer from a raspberry pi until I powered the pi via the printer power supply instead of direct from mains.”

By direct from mains I assume you mean from a wall-wart with USB lead?  Something I learned only recently is that Pis are very sensitive to supply voltage and current capability.  If you see a “lightning bolt” symbol from time to time at the top right of the screen this is the reason.  Lots of mobile phone charger type devices are a bit marginal on voltage and the USB leads can have quite high resistance.  That’s why R-Pi recommend their own supplies which I think have a permanently attached lead.  I have suffered a number of unexpected “crashes” whilst data logging on a Pi which I think can be traced to this – basically the Pi does a reboot.

Have I just discovered a bug?  When I “quote” in Jack’s post  718369 above I get quoted  Dave’s text instead.

[John Haine]

On John Haine Said:

…

Have I just discovered a bug?  When I “quote” in Jack’s post  718369 above I get quoted  Dave’s text instead.

Are you sure about that, John ?

Old habits die hard … and the relevant menu bar is now at the top of a post,  when previously it was at the bottom.

MichaelG.

 

[John Haine]

On John Haine Said:

By direct from mains I assume you mean from a wall-wart with USB lead?  Something I learned only recently is that Pis are very sensitive to supply voltage and current capability.

Wall wart yes, but it was the proper thing. My issue was interference noise when the steppers were running, not insufficient volts.

[Michael Gilligan]

On Michael Gilligan Said:

On John Haine Said:

…

Have I just discovered a bug?  When I “quote” in Jack’s post  718369 above I get quoted  Dave’s text instead.

Are you sure about that, John ?

Old habits die hard … and the relevant menu bar is now at the top of a post,  when previously it was at the bottom.

MichaelG.

 

Ah yes.  And of course there is no clear delineation of the division.  Thanks Michael.

[Author]

Posts