As restaurants are forced by the coronavirus crisis to close dining rooms and serve takeout only, here’s a DIY project to help them make the pivot as safely as possible, for their retail workers and their customers. San Francisco’s robotic burger restaurant, Creator, has designed a take-out transfer window that works like a mini airlock, pressurized so that outside air can’t enter the restaurant. It’s even got a self-sanitizing conveyor belt, and you can build it mostly from aluminum T-slot, hardware from McMaster-Carr, and some free 3D printed files.

No one’s immune from disruption, not even our friends at the high-tech robo-burger joint. But what Creator has that other restaurants don’t is a team of engineers ready to improvise and innovate new tools. Director of hardware engineering Michael Balsamo and a handful of his engineers and fabricators sprinted this project last week, and today they’re “open sourcing” it – sharing the design freely with everyone – to help any retailer, including their competitors, cope with the new realities.

“Our engineers have worked around the clock,” the team writes, “to create a seal that protects the inside of the restaurant from outside air yet still allows staff to transport completed meals, in their hermetically sealed bags, out to guests and delivery workers. The seal works via a special transfer chamber that uses a positive pressure system combined with a self-sanitizing conveyor to transfer goods out of the store without taking in outside air.”

The chamber is pressurized by a Sanyo Denki 24-volt 65CFM blower regulated by simple LM317 voltage regulator circuit. The conveyor belt feeds itself through a 5 gallon bucket of quaternary sanitizing solution. Customers can order through an intercom, and their takeaway bags are heat-sealed and labeled with a tamperproof sticker just to be extra super sanitary.

The plans for building your own “grab-and-go transfer chamber” are shared at www.creator.rest/covid19, including the complete bill of materials and tools needed, detailed fabrication and assembly drawings, and files for 3D printing. You can build it with a hacksaw, tap set, and other basic hand tools if you outsource the 3D prints, but a chop saw will be handy for cutting the aluminum extrusion to size. You’ll also need a soldering iron for the voltage regulator circuit. Bonus points if you’ve got a laser cutter to cut the acrylic windows for the chamber, but you can hand-cut those or order them cut to size.

What’s with that hand crank? “We wanted to be quick with the hand crank,” Balsamo explains. “It works; if we had it powered, we’d still need a way to make it work if the powered option failed, and so another reason to go manual. Makers are welcome to add gearing on it. You can easily power it by 1) Hacky method (we tested): cordless drill, or 2) Pro method: buy a stepper and controller and make it a 1-button press.”

Co-founder Steve Frehn adds, “We used the hand crank versus something motorized to keep it simple, so that people could build this with readily available materials. With the exception of the fan, you could make this barrier anywhere in the world.”

The Creator crew are already food-safety nerds, having engineered a robot that precisely controls cooking temperatures and eliminates human contact during burger preparation inside a transparent, refrigerated assembly line. They’re certainly aware that this project is good PR (Their new slogan: “Be the first to touch your burger”) but it’s also a genuine extension of their expertise and obsessions, and a gift to the restaurant and retail communities.

Check out the project at Creator’s site and maybe you can help your local restaurant build one, find ways to cut the costs, or iterate a better version.

[+] Learn more about Creator’s impressive burger bot in “How They Made: World’s First Cheeseburger Robot.”