I was cutting a part this morning and have experienced several losses of USB connection. It looks like the problem is only present when my router is running. This is definitely not a sleep problem with my PC, which is running Linux continues fine with the screen saver on.
Has anyone else seen this? My router has brushes, as does the Ridgid router, so maybe mine’s a bit noisy.
In the past, I’ve had this happen when the cables were wiggling loose - not visibly wrong, but ‘exercising the connections’ made a difference.
An earlier thread (old forum?) recommended something like these applied to the cable ends. I bought some, but have never gotten around to installing them.
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I’m pretty sure it’s not that as I’ve run for ages with a pencil. It’s only when the router is running that I see this problem. On load and off.
AThen those clip-on noise suppressers might do the trick - electrical noise is just the thing they are supposed to address.
I have had connection problems when Linux went to power save mode, but I don’t use a screensaver so not sure about that situation. I fixed my issue by disabling the power save functionality, using latest Lubuntu.
Another culprit can be another program accessing that serial port. Is anything else running (Arduino)?
No, I don’t think so. Everything is fine for ages until I start the router spinning. I’m going to try some suppression tomorrow, and see if that improves things.
Add ferrites to the router’s power cord, the USB cable (you can get them pre-made with ferrites, and shielded), and the z access cables, if so equipped.
Why back when radio was new they used spark gap transmitters, an electric spark jumping a gap. These were abandoned, and eventually outlawed as radio transmitters because they spray interference across a wide range of frequencies and cause a lot of interference. Today we used brushed motors that arc and spark and generate interference across a wide range of frequencies. Progress!
Those ferrites suppress RFI by acting like molasses (why inductors, which they are, are also called chokes) to higher frequencies (how low/high depends on the ferrite’s “mix”, of which there’s lots). Computer signals are into the radio frequency range, and cables act like antennas that pick up RFI (including harmonics, but that’s another show) and confuse it with valid signals. The ferrite’s help reduce the interference on the wires
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I know Hannah’s computer experience a USB connection drop if I use a particular corded drill near it. I think RF might be a good guess, especially since we have such a long USB cable. The first solution I would look at would be trying a shorter USB cable. It can also be dependent on the computers USB chip and how it handles noise because while Hannah’s computer will drop the connection pretty much 100% of the time if I use that drill, mine won’t be effected.
some USB cables have more shielding than others.
Also, and active USB extension with a short cable on the end will be more
reliable than a long regular cable
try not to run the USB cable along side the power cable.
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I took the router apart this morning and interestingly the motor cables have ferrites built in. I looked at removing an earth loop (by removing the earth on the Maslow motor supply). All was looking good until I powered on my dust extractor and the USB connection was lost immediately. So I think I may be blaming the router when it’s blameless and my dust extractor might be to blame. Or I had an earth loop. I need to do more tests and buy more suppression parts. I’m off for 3 weeks now so it’ll have to be in a months time or so.
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Maybe the dust extractor needs those ferrite’s. 
All this E-smog makes it ever more clear that wireless communication and powertools don’t really play nice together.
try adding shielding to the USB cable, do you have any metal tube you can run
it through?
There are shielded USB cables available, they are normally have clear sheaths and you can see the braided screen inside.
Shielded and ferrite, 24ga power wires, $1.54 for a 6 footer, $2.14 for 15. Bought so many cables they gave me a commercial account.
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I agree with mooselake get a ferrite usb cable and try to keep the length to a minimum. I’ve had this problem with my cnc and the router coupled with a dust collector creates and electrically noisy environment. Also try to connect the controller to a different power source then the router and vac. They have the same earth ground but sometimes putting some distance electrically helps
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Line filters also could help, though the routers power use aks for a very chunky filter…
http://www.powerguru.org/wordpress/wp-content/uploads/2013/11/Single-phase-line-filter.jpg
The impedance of the coils flters out high frequency noise.
I’ve got at least a partial solution to the problems I was having. It looks like the culprit was the router, although the dust extractor may need to be filtered too. I was getting USB problems when using the router without the dust extractor.
So I added a filter to the computer and maslow supply:
https://photos.app.goo.gl/A2smTpqOIuxPfruL2
I also added a line filter to the router supply:
https://photos.app.goo.gl/seV2AzotvIgbl1GD3
The maslow and computer supply filter helped somewhat but the router line filter has made a big improvement. I haven’t seen a USB problem since I added it. I managed to finally cut the part I was trying to do:
https://photos.app.goo.gl/DzrSkVpPXCU7QcQ92
This is cut from 36mm thick scaffolding board and due to the number of cuts needed to get to the final depth it took about an hour. Previously I’d not managed to get through the whole file but with the filter it ran through first time.
So, big improvement or maybe (hopefully) a fix.
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