There have been a fair number of posts recently where people have been experiencing failed jobs or general connectivity issues due to interference on their USB connection between their PC and X-Carve. Using a powered USB hub solves nearly all of those issues, however there exists another solution if you want to make a really long run between your controlling PC and X-Carve…
These devices can be listed as USB print servers, but they’re really just network USB servers (you should be able to connect any kind of USB device at the other end). They do require that you install a piece of communicating software on your PC, but they work great. Essentially, they make your PC think that it’s got extra USB ports wherever you place the little box. They communicate over your home network (so you’ll need a router, but I feel like that’s a pretty common item these days), be it wired or wireless. I’m running both my X-Carve and a vinyl plotter using one of these, and have had zero issues with both (over wired connection - I’m a little wary of relying on the wireless for a continuous 3+ hour job). When I want to jog the machine around and zero the bit to my work piece, I use Google Remote Desktop to log into my controlling PC on my tablet.
I have a pair of ioGEAR USB-to-IP hubs, but the Hawking Technologies one linked above is identical in all aspects (ioGEAR discontinued theirs, but I have a sneaking suspicion that ioGEAR and Hawking Technologies are in cahoots). They can be found on Amazon in the $50-$100 range (USD).
Note also that there exist USB-over-Ethernet adapters, but they only work for point-to-point connections (which, in reality, may be what a person is really after) - you can’t route them through your home network.