Put a restaurant runner, a hotel butler and a hospital courier side by side and they look like the same machine in three shells: a wheeled box, a lidar, a touchscreen. Buyers reasonably assume the robot transfers between venues. The spec sheets say otherwise — and they say it in a way that is easy to misread, because the three venues do not even measure capacity in the same units.
This is the spec-level companion to our July comparison of delivery-robot business cases. That piece asked which category pays back. This one asks a narrower question: read the numbers, and what exactly are you trading away when you move the same vendor's robot from the dining room to the guest floor to the pharmacy?
All specs below were read off the manufacturers' own product pages on July 31, 2026.
The restaurant tier optimises for aisle width and tray access
KEENON's DINERBOT line is a clean test case because one vendor publishes the whole ladder. Per keenon.com, the T10 carries 40 kg total, needs a minimum passage width of 59 cm, and runs 9–12.5 hours on a charge with a 5.5-hour recharge. Its trays are deliberately open — the marketing point is "self-pickup," where the guest or server lifts the plate off without the robot doing anything.
The T11 sits one notch tighter: minimum passage width 49 cm, up to 13.5 hours of battery, 38 kg body. The price of squeezing through a 49 cm aisle is capacity — maximum load drops to 20 kg, and KEENON specifies it per shelf (5 kg on the middle level, 10 kg on the bottom), not as a pooled figure.
That per-shelf split is the first thing worth checking on any tray robot. A "20 kg" runner that can only take 5 kg on the level your servers actually load is not a 20 kg runner in practice.
The hotel tier pays for the lock and the elevator
KEENON's BUTLERBOT W3 is the same company's answer to guest-room delivery, and the trade-offs are explicit on the page: 20 kg total load (half the T10), 70 cm minimum passage width (11 cm wider than the T10, 21 cm wider than the T11), up to 12 hours of battery, 6.5-hour recharge, 7° slope rating.
What you buy with those concessions: up to four independently accessible compartments, each dispatchable to a different location — so one trip can serve four rooms — and what KEENON calls the "IoT Elevator Rider," letting the robot call and board a lift on its own.
Then the price. At RoboBuy, a US dealer stocking both, on the same day: DINERBOT T10 $23,000, BUTLERBOT W3 $29,600. The hotel robot costs 28.7% more and carries half as much.
Stated plainly: in the hospitality tier you are not paying for carrying capacity. You are paying for a lock, a lift integration, and the ability to split one trip four ways. If your building is single-floor and nothing needs to be secured, the premium buys you nothing.
One nuance against the easy generalisation "restaurant robots can't do floors": KEENON's T3, a catering model, also lists autonomous elevator riding — while requiring a 75 cm passage, the widest of the group. Elevator capability is a feature, not a tier.
The hospital tier stops measuring in kilograms
Move to clinical logistics and the spec sheet changes language. ST Engineering Aethon's ZenaRx is rated at more than 10,000 cubic inches of capacity — described by the company as 2.6× the older TUG T2 pharmacy robot — with four secured compartments that can be merged into two larger ones, an all-metal cabinet with physically latched doors, biometric and PIN access, and up to ten hours of runtime. Relay Robotics quotes its RelayRx in 10 gallons (41 litres), twice its previous model.
Neither headline number is a weight. That is not sloppiness: pharmacy and lab payloads are light and bulky, so volume is the binding constraint, and custody matters more than either. Relay states its robots ride elevators autonomously across "all major elevators including OTIS, Schindler, TK, Mitsubishi, KONE" — brand coverage being a procurement question in an old hospital, not a spec-sheet flourish.
The practical consequence for buyers: you cannot rank these robots against each other on payload. A 40 kg restaurant runner and a 10,000-cubic-inch pharmacy robot are answering different questions, and any comparison table that puts them in one column is manufacturing a false ranking.
Cross-venue summary
| Restaurant | Hotel / multi-floor | Hospital pharmacy & lab | |
|---|---|---|---|
| Example | KEENON T10 / T11 | KEENON BUTLERBOT W3 | Aethon ZenaRx · Relay RelayRx |
| Capacity | 40 kg (T10); 20 kg split per shelf (T11) | 20 kg total | >10,000 in³ (ZenaRx); 10 gal / 41 L (RelayRx) |
| Min. passage width | 59 cm (T10); 49 cm (T11) | 70 cm | not published |
| Enclosure | open trays, self-pickup | 4 lockable compartments | metal cabinet, latched doors, biometric + PIN |
| Multi-floor | model-dependent (T3 yes, T10 no) | IoT elevator riding | multi-brand elevator integration |
| Battery | 9–12.5 h (T10); up to 13.5 h (T11) | up to 12 h | up to 10 h (ZenaRx) |
| Published US price | $23,000 (T10, one dealer) | $29,600 (W3, same dealer) | quote only |
One caution on reading vendor spec tables
While collecting the above we hit a live example of why the tables need checking. KEENON's S100 page headlines "100kg+ Load Capacity" — but the Product Parameters table on that same page lists Max. Payload 300 KG, along with dimensions, weight and battery figures identical to the heavier S300 model's table. One of those two numbers is wrong by a factor of three, and it is the number a buyer sizing a load would use. Verified on keenon.com on July 31, 2026.
We have flagged unit and conversion errors on vendor and dealer pages three times in the past two weeks. Treat a spec table as a claim to confirm in writing before purchase, not as a fact.
What to ask, by venue
- Restaurant: measure your tightest aisle at table height, not at the door, then check per-shelf load limits, not the total.
- Hotel: get the elevator make and model into the quote, and confirm the compartment count you need is the configuration being priced.
- Clinical: ask for capacity in volume and for the custody mechanism (latch, biometric, audit log) in writing; ask which elevator brands are supported at your site, not in general.
For category-level context see our hotel service robot and delivery robot pages, and our Bear Robotics Servi price guide for how far published prices for a single restaurant model can diverge.
Sources
- KEENON product pages, specifications read July 31, 2026: DINERBOT T10, DINERBOT T11, DINERBOT T3, BUTLERBOT W3, S100, S300
- Dealer prices, verified July 31, 2026: RoboBuy product pages for KEENON DINERBOT T10 and KEENON W3
- ST Engineering, "ST Engineering Aethon Launches ZenaRx"; Aethon ZenaRx product page
- Relay Robotics, "Relay Announces Next Generation of Delivery Robots for Hospitals"
Capacity, security and elevator claims for ZenaRx and RelayRx are vendor statements; we have not independently tested them. Prices are single-dealer quotes on a single day and will move.
