Akom's Tech Ruminations

Various tech outbursts - code and solutions to practical problems

Increasing capacity of the PetSafe Simply Clean Litter box Hardware Hacks

Posted by Admin • Tuesday, March 10. 2015 • Category: Hardware Hacks

Although I wrote a somewhat harsh review of the PetSafe Simply Clean Litterbox on Amazon, I still felt that there was some potential to this thing. What I wanted most from it was a very low maintenance experience, and having to empty the waste bin every 3 days simply didn't seem to qualify. When I go on vacation (and please don't start a neglect flame war over this) I leave the cats alone - monitored by 4 cameras, auto feeder, 5 gallon water dispenser and many litter boxes. I don't want to bother relatives with the long drive to come over just to clean cat poo, and my cats do not take well to being moved. Or to strangers. Or to basically anything besides the quiet at-home life that is exactly like yesterday.

Therefore, what I'm looking for is a larger waste bin. The litterbox doesn't handle capacity problems well - it backs up, jamming up against the chute cover, making a mess and eventually just shutting itself off. What I need to do is to create a jam-resistant path for the waste to go, somewhat like this patent here. The idea is good but it seems a bit too complex for my taste, and of course it is intended for a rectangular raking box like the LitterMaid. So, I chose to do the simplest and most reliable thing I could think of.

Design

  • The first and most obvious thing is that the whole box has to be raised. Without this, the pile of sticky objects will not vacate the immediate drop zone and will quickly end the experiment. This is no good. The question is: "How high?". Raise it 5 inches or more, and I am not sure if the cats will find it unapproachable. Raise it an inch and perhaps there is no advantage. So I scientifically settled on a 2 inch rise... The fact that I had 2" foam may have had something to do with my decision.
  • The second obstacle is that the box has a bottom (floor) where the waste container goes. This means that any waste dropping down off the escalator will not go anywhere, no matter how high you raise it. Therefore, we need a ramp to guide it into the safety of our new containment system. OK, ramp, got it.
  • Finally, the litter box has more safety switches than you may realize. There is a magnetic switch under the waste bin, and sure enough, there is a magnet in the bin. This is easily remedied with the tiniest of magnets - we simply place one underneath the litterbox directly onto the switch. There is no safety involved in keeping cat poop off the floor, and I think I can be sufficiently responsible to put the waste bin back after I take it out, so we'll not say anything more about the magnet

Implementation

This proved to be fairly easy. I used what I had on hand: Dow Extruded Polystyrene Foam, which was 2" thick. I edge-glued some scrap pieces since they weren't wide enough, but with a full 4' sheet that wouldn't be needed. I used Guerilla glue for everything, it works rather well on foam. Simply placing the litterbox onto the foam and tracing/cutting the foam proved to be sufficient for a fairly neat looking 2" rise.
Raised platform


Now for the ramp. I still had some foam pieces so I simply cut a bunch of triangles until I built it up to the right width. The angle was arbitrary - I wanted it to stay below the ramp (to catch any litter dropping through) and extend mostly to the edge. You can see the result here, it's not pretty but it's also not on display once it is deployed. You can see that I added another layer of 3/4" Styrofoam to make a tight fit.
Test fit


With a tiny magnet under the switch, all I need to do now is jam the ramp in with a garbage bag around it, pull the bag over the ramp (I looped the bag handles over the chute cover aligning pins), and I'm done. Also.. I didn't trust the chute-cover-is-open switch, so I jammed a piece of foam earplug down the hole to keep it on all the time. I'd rather not have a sensor malfunction cause a dirty litter box when I'm away.
Bag installation. NOTE: I did it wrong, ramp should stay outside the bag!
Finished

Findings

After a week of continuous operation, the bag seems to have considerable capacity left, so I feel that I achieved the result I was after. The trick to making it low maintenance is to use a bit more litter initially, so that it lasts until the next bag change when you can top it off. The litter box groans and clicks with the added strain, but to be fair it does so regardless.

Adding Litter

The next problem relevant for unattended operation of a litterbox is keeping it from running out of litter. Each time it cycles and matter rides the escalator into the bag, the litter level drops. Eventually it's a thin layer that is quickly saturated and sticks to everything, making it quite useless. With two cats I find that I'm topping it off every 3 days or so. This isn't great if you plan to go on vacation. Naturally I started thinking about a method to automatically add litter, something that would not be overly complex and would be unlikely to overfill the box. I went through some hideously cumbersome ideas before arriving at something incredibly ugly but strangely simple: A piece of PVC pipe sticking out of a litter container. That's it. Now, granted, this will only work if everything is exactly the same as my setup, but still:
Advanced Automatic Top-Off system
I suspect that this will require tweaking, but it's working OK so far. All it is a piece of 3/4" PVC pipe and a threaded fitting. When I get a new box of litter, I make a hole in the side with a holesaw, and the threaded fitting screws right in. It's just a matter of getting the length right. It will dispense at least half the box before it will need shaking to redistribute contents, and I am OK with this, it should still last quite some time.

Summary

These are the steps I had to take to make this thing a good solution for maintenance-free litterboxing:
  1. Raise the box. The higher the better for waste capacity
  2. Make a guide that directs waste into the bag
  3. Bypass sensors (sounds harder than it is)
  4. Make a threaded pipe piece to dispense fresh litter
Additionally, since my cats kept going out of the box, I hot-glued a bunch of plastic (pieces of buckets) to make a taller fence. Oh and I happened to make an Arduino motion-detection controller for the box, but that is more of a luxury than a necessity. Let me know if you find this useful.

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1 Comments

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  1. Hi! Just thought I'd let you know I checked out your PetSafe litterbox modification and thought it was a pretty interesting idea. Thanks for sharing your idea!

    -Ray

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