Safe self-cleaning litter box for heavy older cats

A rotating globe tipping over with your cat inside — that's genuinely alarming, and I completely understand why you want something more solid before trying again. Self-cleaning boxes really can reduce daily scooping and keep things fresher, which is worth pursuing, but they vary enormously in stability. The globe-style designs sit high and have a narrow base, which makes them a real risk with a heavier cat shifting their weight mid-cycle. Before I point you in the right direction: is this mainly about getting back to the convenience of automatic cleaning, or has the incident put your cat off using the box altogether? And roughly how much does your cat weigh?

6kg is solidly in the heavy-cat bracket, so stability genuinely matters here. A few quick things that'll help me narrow it down: is she still happy to use a standard tray in the meantime, or is she showing any signs of hesitation? And does she prefer an open box or is she used to having some enclosure around her?

That's really helpful. She likes enclosure and she'll use a normal tray, so she's not box-shy — you're in a good position. Given her size, her age, and the fact that you need something that absolutely won't tip or rock, I'd go with the LitterMaid Mega Self-Cleaning Litter Box. It sits flat on the floor with a wide, low-profile rectangular footprint — nothing to tip, no rotating mechanism, no elevated base. The rake mechanism runs along a fixed track at ground level, which means there's nothing that shifts or destabilises under a 6kg cat moving around. The Mega size specifically is built for large cats, so she won't feel cramped. It uses standard clumping litter rather than a proprietary type, which keeps ongoing costs reasonable. It's available on Amazon UK and sits in the mid-range price bracket. The one honest caveat: it has a hood rather than a full enclosure like a globe, so it's more open-feeling — but given she's comfortable with her current open tray, I'd expect her to adapt quickly. Avoid anything globe or drum-shaped going forward; the top-heavy designs are a recurring problem with bigger cats.

Yes — a few things that genuinely help. Put the new box right next to her current tray rather than replacing it immediately. Let her explore it switched off for several days before you run the rake for the first time. When you do turn it on, do it when she's not in or near it so she can hear it from a distance first. She's ten, so she may be a little more cautious than a younger cat, but because she's already comfortable with open trays and she doesn't seem traumatised by the incident itself, she'll most likely settle into it within a couple of weeks. The main thing is not to rush the transition.

Good choice for her — the low stable base is exactly what you need. Keep the old tray available for the first week or two just in case, and run the rake on a longer delay cycle initially so she doesn't get startled by it activating too soon after she's used it. Hope she takes to it without any fuss.