The grinder that grinds and rolls while you kick back
Hand-grinding is the one part of the ritual nobody actually enjoys — sticky fingers, an uneven grind, half your flower stuck in the teeth. The OG OTTO from Banana Bros deletes that chore entirely. It's the first, and still the only, automatic milling machine built for flower: a palm-friendly countertop device that grinds your herb to a consistent, cone-ready texture and packs it straight into a King or Shorty cone in seconds. Load it, tap it, and walk away with a filled pre-roll. No grinder, no rolling tray, no dexterity required.
What's under the hood
The OTTO's trick is that it thinks. An onboard AI-driven system reads the material as it works and automatically adjusts the milling blades' direction, speed, and pressure, so dense sticky flower and light dry flower both come out evenly milled instead of pulverized. The grinding surfaces are aerospace-engineered aluminum milling plates, and the chamber expands to handle a real amount of flower rather than a pinch. Once it's milled, the included O-Tube connector funnels the ground flower directly into the cone, filling it uniformly from base to tip.
- Function: automatic mill and cone filler in one device
- Milling: AI-adjusted blade direction, speed, and pressure for a consistent grind
- Plates: aerospace-engineered aluminum milling plates
- Chamber: expandable capacity
- Cone compatibility: King size and Shorty cones
- Power: USB rechargeable
- In the box: OTTO device, O-Tube connector, and accessories kit
The OTTO earns its counter space for anyone who rolls more than they smoke out of glass. Daily joint smokers, people with arthritis or limited hand mobility, hosts who need to fill a tray of pre-rolls before friends show up, and anyone who's simply over the grind-and-roll routine. It's also a genuinely good gift for the person who owns every piece of glass but still fights with a paper.
If you're a purist who loves the tactile ritual of rolling by hand, this isn't aimed at you, and that's fine — it's for the crowd that wants a clean cone in the time it takes to find a lighter.
Plenty of so-called electric grinders just spin a blade and spit chopped flower into a cup; you still have to pack the cone yourself. The OTTO is the only device that closes the loop, taking you from whole nug to filled cone without a second tool touching the flower.
The AI-adjusted milling is the part that actually matters: it's the difference between a cone that pulls smooth and one packed too tight to hit or too loose to stay lit. At $129.99 (down from $159.99), it lands below the price of a nice portable vaporizer while replacing a grinder, a rolling tray, and the twenty minutes you'd otherwise spend rolling a session's worth of joints.
For a household that moves through pre-rolls, the convenience pays for itself quickly.
Banana Bros built the OTTO for the moment pre-rolls stopped being the lazy option and became the format. Dispensary shelves are stacked with singles, multipacks, infused cones, and designer papers — the joint is having a full renaissance, and the OTTO is the home version of the machines that pack them at scale.
It's the countertop-appliance energy the category has been missing: the same "why am I still doing this by hand?" logic that gave us pod coffee and stand mixers, pointed squarely at flower. Keep it next to the grinder you'll stop reaching for, and treat the milling plates to an occasional brush-out so the grind stays crisp. 21+ only.