Sending to port Failed

I have made my little x-carve machine based on Arduino, CNC Shield and GRBL 0.9j.
All works fine, moving is ok, communication between PC (UGS and Easel) is ok. Problem
is only when I switch on my spindler. I have used 12-24V Lathe Press Motor with Drill Chuck.
When I switch on this motor, Easel lost connection with Arduino. In Device Manager is port OK,
but in programs (Easel and UGS) is this not OK. In UGS i became message “Sending to port
failed.” Can you help me with this problem?
Thanks, Julo

Probability is pulling too much power.
You can use external 24VDC power supply and control that spindle with the relay connected to Arduino. Just like connected Dewalt.

Feeding the Arduino board seperate power (7-12V) may also help.

You have either a power surge at spindle start that make the Arduino USB connection droop out, and/or electrical noise from your spindle causing the same.

My spindle is not connected with CNC shield, for spindle I have other power supply.

What is “proper grounding techniques”? Is there some picture, where can I found this?

It is very generic, as your problem is of a generic character.

You have electrical noise that cause problems, you may try:
Feed external power to your Arduino (a 9V battery may suffice for testing)
Keep power wires and signal wires seperate from each other (increase distance)
Keep power wires/stepper motor wires away from USB cable.
Use a USB cable with wire mesh shield / ferrit chokes (to surpress noise picked up by the cable)

1 Like

Edit: Deleted brain dead reply. Did not comprehend.

Error message :sending to port failed ,while streaming .nc file to arduino
Sys.Arduino uno ,cnc Shield v3,GRBL 3.6.1,UGCS 2 stepper driver Drv 8825

Hi Dear Julo

I have exactly the your same problem. I make a CNC about 4 months ago and I used of Arduino and a spindle water cool that it run by an inverter generator (that I have connected both with a 4-string wire without electromagnetic protection because I have read, do not have to use of the electromagnetic protective wire to connect the inverter and the three-phase electromotor ) and I used of my CNC for 4 months with out any problem but now, when I run inverter to turn on spindle, in GRBL was writing “sending to port filed”. I didn’t change any of device in my CNC

If you find the solve of problem, please help me to solve it!

Thanks and regards