can't see other computers in network behind router

At the office I have a render farm (only 4 computers)
hooked up via a Linksys router.

One of the small Linksys home/small office routers, right?

We have many other
computers in the office we will use at night for
rendering that are in the "wider" network - outside
the router configuration.

There's another router there, possibly another Linksys, almost certainly another home/small office router, right?

My computer inside the
router network can't see the computers in the "wide"
network and vice versa.

Both routers run NAT and DHCP, and both use Class C nets and the C they use is 192.168.0.x, right?

Any suggestions?

If you set the router with the render farm correctly (example: use a different subnet...) then you can make those machines see the machines on the other net. You're going to have major problems having the machines on the other net see past the router to the small net. The router's job is to block just that. That's what NAT is there for!

When you say "see" the other computers, what do you mean? Are you connecting by name, ip address, browsing for them, etc.?

If you're connecting by ip address it's most likely a router configuration problem.

If you're connecting by name with DNS server(s) in place, it could be a DNS problem.

If you're connecting by name without DNS or browsing, you're using Bonjour which uses multicasts to advertise names and services. These are generally not passed between networks seperated by a router.