I have to tell you something about my experience:
I got several fails with my Ender 3pro communicating with octopi. Something like 20% resend and above, all the time broken prints. And I used not really bad cables to connect. But it was still better to print by SD-Card. Than I took an usual usb data cable, cut it shorten on 15cm, disconnect the black wire. I solded a wire at the metalplug on the big USB-side and wrap it with Aluminumfoil around that cable.
There no more fails or issues! The communication is perfect!
So don’t use bad and cheap cables!
Hope you understand my English, Greetings from Germany!
YES! It's a shame there are so many bad cables out there and nobody can look inside.
I just had a very bad experience with an external USB hard drive. Many communication errors have occurred with the original cable. After changing the USB cable, everything works fine now.
Yes, it’s just a blank wire wich is wrapped in the aluminum foil. It connects the foil with the outer plug to make a shield. I’ll try to make a sketch:
i had similar Problems ( ender 3 pro / raspberry pi 3b+ )
i did try several fixes i found on the internet ( and in this Forum ) :
made sure the Power supply for the pi was strong enough
i did try several USB cables ( some only 15cm long and heavily shielded )
taped up the 5V connector on the USB Cable ( to stop the printer from leaching power from the pi )
connected the Ground from the pi with the frame of the Printer
and all those helped but the issue didn't go away entirely...
what did make it go away was when i shielded the Ribbon cable that goes from the Printer Mainboard to the display of the Printer !
i wrapped it in Aluminium Foil and connected that to the frame ( to ground it ) and then wrapped it all up in Tape ( so it didn't come in contact with any other electronics )
pretty much the same way you did with the usb cable
apparently the Ribbon cable on der New ender 3 Pro picks up a lot of interference from the Stepper Motor
Upper Left Corner of the Octoprint UI, that's what mine looks like right now:
Resend ratio: 0 / 136.1K (0%)
0 means no resends ( Good )
136,1K are the total commands send to your Printer ( in this session )
every time octoprint needs to resend a command to your printer the counter goes up.
at about 10% resent ratio octoprint gives you a warning ( but at 10% you probably already have bad print quality )
It’s not necessary to shield the cable, if it’s a quality data cable. Now I bought a new short 50cm cable. But it’s important to plug of the powerline. I did it by a small tape in the plug, like seen here: