There has to a be lesson here: when making a device that solves a problem, make sure that the failure mode isn't worse than the problem you're looking to solve.

I wonder if there's something about your cats' diet that renders their excretions too incompatible with what the robots are designed for.

When we switched from commercial food to the homemade recipe on catinfo.org, the feces of all three cats in my home went from being the stereotypical, wet, stinky kind, to being dry and nearly odorless. (In addition to other visible and invisible health benefits).

Although the robots we use [1] handled the wet feces OK enough, the new feces ended up consuming less litter (i.e. approximately zero, with only urine consuming any) thereby slightly reducing the frequency of waste drawer filling up, requiring less frequent full emptying/cleaning of the robot itself, and never requiring an emptying of the waste drawer due to odor (rather than filled capacity).

[1] Litter-Robot IIs and one LR III. I'm less of a fan of the III, as it has a smaller effective waste drawer capacity before complaining of fullness and takes up significantly more space, meaning there are fewer locations it can go in. Considering how big the LR-II is to begin with, that's a problem.

Even if it's not, this

> I wonder if there's something about your cats' diet that renders their excretions too incompatible with what the robots are designed for.

Is strangely funny and backwards, in my opinion

It is not.

> backwards, in my opinion

What would be the forwards way to express the same concept?

Do you not see the cold irony in expecting the cat to poop in a way the robot can handle?

That (what the GP/OC expressed) omits the intellectual-curiosity point I was trying to get across: why?

Is there something backwards in my wondering about the reason for the mismatch?

> Do you not see the cold irony in expecting the cat to poop in a way the robot can handle?

That borders on being an uncharitable interpretation of my comment. I certainly have no such expectation (and certainly did not say so), but, as an engineer, especially on HN, I see no coldness nor irony in if the designers of the robot had certain expectations as to what the majority of domestic cat feces would be like.

Now I fear you're just putting words in my mouth, and certainly not responding to the strongest possible reading of my comment.

Regardless, the implication that any domestic animal can have a diet that is not manipulated in the first place, stretches credibility.

> Could you imagine if the toilet required you to eat a certain diet?

Let's use a more accurate analogy, of a toilet that requires I not eat a certain diet, but where the vast majority of other diets, including an overall healthier one, are acceptable.

I don't need to imagine. That's all low-flow toilets and a low-fiber diet.

The Litter Robot is essentially an automated/motorized version of this. Interestingly, according to a friend of mine who ran experiments with his cats, the robot version was noticeably more efficient in terms of litter consumed (and this prompted him to replace the manual versions with the robots on a faster schedule, since clumping litter is a non-zero expense).

Cleaning process is just rolling the whole thing 180 degrees and rolling it back. The clumps and poop will drop in the drawer, ready for disposal. Literally 15 seconds task.

Interesting. How expensive is cat litter where he lives? For me, it is indeed a non-zero expense, but also mostly unnoticeable one. Definitely not worth replacing with a robot that'll most likely take more than a year to pay itself back - and I don't expect this kind of tech to run continuously for a year without major, expensive breakage.

It's the US, so about $10 for 35lbs of "Litter Purrfect" from Costco. Around 20lbs/month/cat was his pre-robot, usage, IIRC, and he had multiple cats.

> For me, it is indeed a non-zero expense, but also mostly unnoticeable one.

Every non-zero expense is noticeable to someone living frugally, since they can easily add up if left unnoticed.

> Definitely not worth replacing with a robot that'll most likely take more than a year to pay itself back

To be clear, he wasn't basing the purchase decision itself on the cost savings in litter, merely accelerating the timing of the purchases. He had already decided to "splurge" on replacing all the manual litterboxes with robots.

> I don't expect this kind of tech to run continuously for a year without major, expensive breakage

Most of the tech's actually remarkably simple (for the LR-II model, anyway), which means, in a way, it's overpriced, but the market bears it. The standard warranty is 18 months, and the extended warranty (another $50 or $100?) doubles that.

Personally, I've had them last over 5 years, with the main failures being the electronics (cheap and easy to replace, unlike many other products), power supply wall wart (which I merely replace myself with a better one), and a metal spring for the "waste door" (not as easy, but the parts were free, and it's a very old-age failure).

Oh my. Noooooo thank you.