My main router is a HH6.
I appreciate that I can attach a USB printer to it and it's then accessible across the network. However I don't want the printer in the same location as the HH6
I have a spare HH6 (and an old HH2)
Is it possible to use the second HH6 (or the HH2) as a wifi client and attach the printer to this second HH6 (or HH2) to share the printer?
No, you can't use a Hub as a wifi client, you can only connect it to the network via Ethernet.
The USB on the hubs is at best "flacky" and is not designed to be a printer access point. It is more for connecting a Pen Drive or a portable Hard Drive.
Is your printer wifi capable? If it is why not just connect it to the "main" HH6 by wireless.
You will need to get a wireless print server and connect that to your hub then connect the printer to that via USB.
If you have a PC you could connect your printer to that and set it up as a "network" printer and as long as your PC is turned on, devices on the same network should be able to print through the PC acting as a server.
You could of course buy a wireless printer which could be cheaper than the cost of a wireless print server.