I’ve seen too many good web pages disappear so I’m reposting this cage mod description from AcroRATics here. You can follow this link for a detailed description of how the mod was constructed.
by AcroRATics March 21, 2015
A panoramic view.
A straight view down the longer tube.
The digging box contains oven-sterilized topsoil and cat grass (wheatgrass).
A grow lamp on a 12 hour timer nurtures the grass and provides a daylight feel.
Right cage top.
Right cage bottom.
Left cage top.
Left cage bottom.
The tubes provide just enough room for any two full-grown rats to pass each other.
Some squeezing may be required...
The rats love to forage for the grass seed.
Although they explored the tubes very cautiously the first day, they now scamper through them at incredible speeds... especially if it's feeding time :3
Soon.
A later round of grass in the digging box. The ramps were removed to allow better digging opportunities.
Once the grass is gone, the rats go to town creating elaborate burrows!
Enjoying grapes.
Bosom buddies.
Feetsies.
Olive guards the tunnel entrance.
Nested in the flower pot.
An alternate configuration used while the digging box is being changed.
Photograph demonstrating the tunnel design. Horizontal bars were cut to allow a small section of 4" schedule 40 PVC pipe to fit through. The pipe is secured tightly inside of two closet flanges of the 'over 4 inch' size. The clear tubes are constructed from 4.5" OD extruded acrylic, with PVC couplings glued to the ends. Note: It is impossible to slide the pipe section through without extensively sanding the inside of the flanges. Please don't cut your cage bars trying to recreate this setup unless you're certain you can first accomplish this! See here for more details on this project's construction: http://imgur.com/a/1s5aH.
A variety of fittings can be attached, including caps should the cages ever need to function independently.
My girlfriend and I have a Critter Nation and four rats each. We moved in together and Brady Bunch'd them. With the help of a friend, we created this cage mod to connect the cages along with a suspended digging box to provide them with enrichment.
I’ve seen too many good web pages disappear so I’m reposting this cage mod how-to description from AcroRATics here. You can follow this link to see the main picture post.
by AcroRATics Mar 26, 2015
The most difficult part of the project by far is getting the PVC section to fit into these flanges.
These toilet flanges are tapered on the inside and are designed to wedge at the end of PVC pipe but never let it slip all the way through. If you can find a more suitable flange that would be great but we have not found one. These need to be sanded extensively on the inside or the pipe will not fit. This is serious work, and my friend recommends either an oscillating sander or a lathe for this task. But don't sand too much or the pipe will not fit tightly enough. The flanges are available in both white and black plastic, and we found that the white flanges were made of a material which was easier to sand, so I will recommend you go with those if you can find them. It will also take a good bit of muscle to force the flange down the pipe, and a rubber mallet will be useful.
You'll need a small piece of regular straight 4" schedule 40 PVC pipe. I got a two foot section from the hardware store, which was sufficient. The piece shown is exactly 8 inches long. It is difficult to make a clean, straight cut with a hacksaw, so a band saw or circular saw is recommended.
Once you're convinced that you can make the flanges fit, place the section of pipe next to the cage at the height you would like the mod to go, and mark the bars which will need to be cut. We cut exactly nine horizontal bars on each cage. A square shaped hole will be created. My friend used a Dremel tool with a cut-off wheel attachment rated for metal to make the cuts.
The two flanges are tightened together with 5/16" hex bolts (1.5" long) and nuts and washers. When the attachment is complete, there should be small sections of pipe sticking out evenly on each side.
The tube construction is comparatively simple. This is where I purchased the clear tubing.
The 4.5" OD size fits perfectly into the hubs of 4-inch PVC fittings, but it was the most expensive component of the project. The minimum order is 6 feet and that cost me $81, including shipping. Wrap the cut site of the tubing with painter's or masking tape to help prevent shattering. Cut the tubing to length with a band saw or circular saw, preferably one with a higher speed and a blade with teeth that are closer together. Glue PVC couplings to each end of the finished tubing with PVC cement.
The entrances were created the same way as with the cages, but instead of cutting cage bars, you will need to cut the plastic. The hole for the PVC pipe section was cut using a hole cutter Dremel attachment. The PVC section used was only 6 inches long because none of it sticks out past the flange on the inside of the tote. The pilot holes for the bolts were cut with a power drill and a 5/16" spade bit. The tote has a slight taper to its sides, and this was offset by adding a couple washers on the outside of the box on the bottom two bolts (as pictured) and mirrored on the inside of the tote for the top two bolts.
Here, Brodie demonstrates the the load bearing 5/16" all-thread going through the tote. The all-thread is held in place with 5/16" fender washers and nuts which are secured permanently to each side of the tote with gorilla glue to spread the load.
The digging box is suspended by chain and attached to ceiling studs with eye hooks and quick links. We made sure all suspension components could bear at least 50 pounds for good measure (a system with 4 chains rated for 50 pounds each should be able to hold up to 150 pounds). The all-thread can be slipped through one of the chain links to bring the box to the appropriate height.
To provide better ventilation, the lid to the tote was cut open with a Dremel tool using a cut-off wheel rated for plastics. Half-inch hardware cloth was cut to size and secured to the lid with nuts, bolts, and washers on each side. A spade bit was used to make the pilot holes for the bolts.
Since I posted the album of my rat cage setup here http://imgur.com/a/Veliu I've had a number of people ask how they can recreate it. Although this is not a complete step-by-step guide, this album hopefully provides a few additional details on its construction.
Disclaimer: We have only created this setup once, and I cannot guarantee your success, your mileage may vary, etc. Some steps are difficult and you will need power tools and probably access to a work shop. Questions can be PM'ed to Reddit user AcroRATics.
