Automatic Litterbox Central

Here’s one more example of how to increase the waste capacity for the Litter Robot – In my case, the LR I.

Version I of the Litter Robot has a waste drawer that’s even smaller than the current version. Unfortunately, I found the waste would all drop into the same place in the drawer, resulting in an “equator of feces” (as described by Kurt in this thread) in a matter of two days. That led me to the web where I found this forum. Many thanks to Jen and everyone else for all the excellent ideas.

The box I built seems to be slightly taller than the others pictured in this thread. That’s partly due to my designing and building at the same time. But I did want it a bit on the tall side so I could use a coffee can and bucket as described below. The height is not a problem for my very long cat; He can stand on his hind feet to check out the top of the bathroom vanity. He can also save his energy by stepping directly onto the top of the box from the stairs.

Build Progression
1. Built the box and cut a hole in the top large enough to accommodate a large (34.5 oz.) coffee can.

2. Removed the LR drawer and cut a hole through the bottom of the base, again large enough to accommodate a large coffee can.

I don’t think a replacement drawer is available for the LR I, so rather than cutting a hole in it, it’s sitting in storage. And the hole cut in the base does not affect the operation of the drawer so the LR can be reverted to drawer-only if desired.

3. I then cut the bottom center out of a large plastic serving bowl (from the dollar store) and also from the bottom of the coffee can. The remaining metal coffee can tube was then epoxied to the bottom of the bowl. The bowl measured approximately 12 inches across and 4.5 inches deep.

4. The screws in the LR base were removed so the top of the base came loose. The bowl-can assembly was then inserted through the hole in the base and the top of the LR base was reattached. The bowl is wider than the opening in the top of the base, so everything that drops out of the globe will be properly funneled.

5. At this point, the LR base could be placed on top of the box with the coffee can protruding through the hole and into the box.

6. I immediately noticed the cat sensor did not want to trip when my cat used the LR. I found that the whole front of the base flexed noticeably when weight was placed on the front of the globe. So, with the drawer no longer in place the flexing plastic of the base was absorbing any extra weight and the sensor was not tripping. I installed a piece of scrap plywood in front to shore up the drawer opening and found the cat sensor worked much better than it ever did even with the drawer in place.

This seems to indicate a design flaw in the Litter Robot I, and possibly in the current version. Either the plastic in the base needs to be thicker and/or stiffer, or there needs to be a metal header directly above the drawer opening to properly distribute weight directly to the cat sensor. Someone with the inclination (and an out-of-warranty LR) could probably bolt a thin metal band inside the base, just above the drawer opening.

7. A small pail with an 8 gallon plastic bag liner was placed in the box directly below the protruding coffee can. If odor control is an issue, the plastic bag can be attached to the coffee can with a rubber band. Lying on the floor to situate the rubber band is a pain, so if anyone has a suggestion for quickly attaching the bag to the 6 inch diameter coffee can I’d love to hear it.

8. Since the drawer was no longer being used, I needed to provide a step or ramp for easy entrance into the globe. Even with the drawer in place I noticed that when leaving the LR, my cat would literally jump out of the box before turning around and burying his business. Not only did that tend to scatter litter, it also seemed like a less than ideal situation for the cat. So, I decided to build a large step so he can easily step in and out of the globe. It seems to work well, and I would recommend a wide step in front of the globe even for those who make no modifications.

At some point I’ll probably recess the top of the box where the LR sits and just do away with the step. Then, the cat can step directly into the globe from the top of the box.

9. I covered the top of the box and the step with indoor-outdoor carpet to help control litter scatter. It's really, really cheap at Home Depot, sold on big rolls.

Here are a few pictures.



Here's the basic box, with the hole cut in the top.



The dollar store bowl with the coffee can sleeve attached. The bowl tended to swing and rattle a bit as it sat in the base, so I created the cloth ring on the right to fit at the top of the coffee can.



This picture shows the bowl-can assembly installed in the base, with the base in place on top of the box. Notice the bowl extends beyond the opening in the top of the base, ensuring that everything dropping out of the globe is properly funneled.



Here's the completed project, with the step next to the globe. The step is 7 inches tall and could stand to be one or two inches shorter, but the cat doesn't seem to mind at all. Those are his headlights on the stairs.



Another view of the box and LR with step. In true cat fashion, my cat would not sit still next to the box so I could take a picture - but part of his head frequently popped into the corner of my pictures.



After removing the drawer, the cat sensor barely worked. I installed this brace to keep the plastic base from flexing, and it worked great. The cat sensor worked better than it had with the drawer in place. In the base, you can see a piece of round poly rope wrapped around the top of the can where it attaches to the bowl. The poly rope replaces the cloth ring I created earlier, and is effective at keeping the bowl-can assembly from moving around and rattling.



Here's a picture of the box with the front open. The pail is lined with an 8 gallon plastic bag and sits directly below the coffee can. No, I will NOT wait until the pail is filled before emptying! There's also plenty of room for storage, and I may add a shelf or two.

I love seeing new ideas!

To all who modify their Litter Robots.
I guess I don't see what the big deal is. I can't imagine not emptying the box once a day. The smell alone from the filling of the modified box would be a reason not to do it. How can't the smell be overpowering with everyone not emptying the box for days if not weeks? i think the Litter Robot has a big enough receptacle, and I've got 3 cats. I empty it once a day, no more. I consider myself pretty lazy, but to not empty it at least once is pretty gross. My cats would not use the box if the smell was bad.
Anyway, if it works for you, great. It just grosses me out that you would have a trash can full of a weeks worth of waste. I can't even imagine the smell from so much poo and pee.
This is just my opinion only. To each their own.

I think the best modification I've seen is adding a battery backup to the Robot. I bought one for $40, and it works great if the power goes out.

gman -
The experiences that contribute to everyone's opinions are not all the same.

In my particular case, my cat had chronic urinary tract problems until I began feeding him 'Purina ONE Urinary Tract Health Formula' dry food. I quickly found this food results in extremely low odor in my cat's feces. In fact, it was rare for me to smell any odors even when my cat was using an open litter box. I've read elsewhere on the web that others have had the same experience. What you feed your cats does determine litter box odors.

Aside from that I keep my Litter Robot (LRI) in my basement, where I normally only visit when doing laundry or to tend to the litter box. Because my cat eats dry food, he also drinks a surprising amount of water - so much so that my vet has tested him a couple of times for diabetes. Due to the large amount of water going into and out of my cat, I found that if I forgot and let my LRI go for two days unattended, I would occasionally find a ring of feces smeared around the globe. This was due to lots of very large pee clumps piling up in one spot, as well as the shallow drawer in my LR I. I decided on the modifications in order to eliminate the ring of feces. The small bucket for my modification was chosen because it has high sides and will keep litter from bouncing out of the receptacle. I do empty the bucket frequently, and almost never detect any odors even when performing that chore.

An added benefit to my modifications is that the cat sensor now works beautifully. Before I shored up the drawer opening it was very tricky to adjust so that it worked properly.

Perhaps this info will help to clarify why some people may want to modify their bots.
- Jack

I have not made a modification, but can see the beauty in doing so. I have 5 cats that use the LR, so far with no difficulty (going on 6 months). But it does tend to build up quickly. And I too have had the ring of poo, rubbed on the outside of the ball as it rotates, when it clustered in the middle and I forgot to even it out. That is another reason to perhaps make a modification. By the way, has anyone found the best way to clean the outside of a LR when something like this happens? I have scrubbed and used several different things, but after it dries, there's still some "there" there. Anyway, back to the topic. I also have a spinal cord injury, another reason I took the plunge and purchased, it was getting too much to go around cleaning all the boxes, but for people even worse off than myself, some type of mod might be a necessity. Also, sometimes there are people that might take weekend trips and not want to come back to a feces smeared ball. Wow, I left myself open on that one. So there are many reasons, other than just laziness, that I can see a use for modifications.