Overhead trolley for Festool vac hose

[Alan S]

If you want it to work like a curtain rod but be able to go around curves, you might consider something like this:
http://woodgears.ca/curtain_rods/corner.html

[Gary G™]

Or
https://www.mcmaster.com/#cable-trolleys/=1dbmkq4

[Cecil]

How about some cable, a turnbuckle, and some pulleys. 




The "M15" pulleys are $10.59 /5 on Amazon.  Should not be much more at a local hardware. 

If you don't need a long run, steel rod may work too, though a long run likely would sag in the middle, causing the pulleys to gravitate toward the middle.

[Cooler]

I may just mount one of my boom arms from  my photo studio.

It swings side to side in an arc.  It wall mounts.

[WaterlooMarc]

Cooler, that’s almost exactly what I use.

[Cooler]

Cooler, that’s almost exactly what I use.

This swings in an arc, and the saw travels in a straight line.   It did not seem like it would work that well.  

I have two wall mounted ones and one light stand mounted one.  So it would not be a problem to try it out.  

Cooler.