Hey! This thing is still a Work in Progress. Files, instructions, and other stuff might change!

Counterbot UVC Countertop Sanitizer

by LoboCNC, published

Counterbot UVC Countertop Sanitizer by LoboCNC Mar 11, 2015

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14754Views 833Downloads Found in Kitchen & Dining


This little bot will roam your countertops, Roomba-style, sanitizing your work surfaces with high-intensity UVC light. This version is just a demonstration prototype (it still needs control electronics and software) but a complete future version will include:

  • Bump sensing, drop-off sensing, tilt sensing
  • Safety and auto-timer shutoffs
  • Navigation Algorithm
  • Wall charger unit

See it move at: https://youtu.be/2rI_AWi3CdA


To build this version, you will need:
1 - CVS pocket-sized UVC Sanitizing Wand, cannibalized (from e-bay)
1 – EG2208 2-pole slide switch (from Digikey)
2 - GH12-1324Y gear motors (from Jameco)
2 - 3/32” thick, 3/4” ID O-rings for tires
4 - AA batteries (preferably with welded tabs)
5 – 4-40 x 3/8” socket cap screws
hookup wire,superglue, foam tape

CAUTION: The UV light can damage your eyes! Do not stare into the UV light or shine it on your pets, children, etc.!

  1. Print one TOP part, one BOTTOM part and two WHEEL parts. The BOTTOM part will need to be printed with supports.
  2. Remove the covers from the sanitizer. Unsolder the lamp leads and the battery terminal leads from the driver board. Remove the driver board, the lamp and the reflector. Insert the reflector/lamp assembly into the slot in the BOTTOM – the rubber grommet around the leads should fit snugly between the posts at the end of the slot. Screw the driver board onto the mounting posts with 2 screws and re-attach the lamp wires.
  3. Scotch tape the 4 batteries together and interconnect them + to – to form a 6v cell. (I was bad and soldered wires directly to standard batteries – not recommended!) Insert the battery pack into the clip.
  4. Use an abrasive wheel to cut the motor shaft down to 3/16” in length. Assemble the O-rings onto the wheels and press the wheels onto the motor shafts, leaving a small gap between the wheel and the motor. Put a small piece of foam tape on the side of the gearhead housing that will touch the TOP. Place the motors and wheels into the BOTTOM.
  5. Use a tiny amount of superglue to glue the slide switch onto the notch above the switch cutout in the BOTTOM. The slider should be facing the cutout and the pins should be pointing towards the inside.
  6. Wire everything up according to the wiring diagram.
  7. Assemble the TOP to the BOTTOM with 3 screws.

Note that the UV lamp driver has a built-in tilt switch that will turn off the UV lamp if the board is tilted upwards. Even so, take care not to shine the light into anyone's eyes.

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It is so cute and tiny! Love the over the counter view where you see it slowly move over the top. So cute!

Why didn't you put some simple light or F-stop turn controllers in there? Kinda defeats the purpose when it runs right off the counter. And cutting the vid before it runs into stuff, turning it, placing it elsewhere and restarting vid, doesn't fool anyone dude. It red flags it.

May 3, 2015 - Modified May 3, 2015
jpod - in reply to DevWolf

@devwolf - I don't think anyone was "fooled" by the current state of the project.

@LoboCNC - Great idea, thanks for sharing. Looks like we could fit an Arduino Nano in there for sensing and control. This platform has a lot of potential. I see some great remix possibilities too. I think adding a little crumb strip at the front would be a good idea. Thanks again!

Dev if you went to Thing Info you could have read about this very easily...

@devwolf - No intent to fool anyone - in the description it states that this is a "demonstration prototype" that still needs control electronics and software, and in the video, it is labeled a "conceptual prototype". This was an entry for the Countertop Challenge, and given only 2 weeks to work on it, I didn't have time to implement a fully functional version.

Approximate cost of your prototype?

I used mostly spare parts I had lying around - the only thing I purchased was a sanitizer wand for $12 on ebay. I think the particular motors I used are $18 (new) from Jameco. Other than that, there's only a couple of dollars in screws, O-rings and a switch. Of course, a real working version with a brain (like an arduino controller) will be more.

This should be on Kickstarter!!

Great Idea!!! Could use one at work, nasty co-workers. Would be great if had smaller motors, rechargeable lithium battery system with wireless power charging on top. Could even design a docking station for the little bot to charge up when it is done. Also are there infrared sensor on the outer wall? How does it prevent from bumping into things like my coffee? with a little tinkering could be work thousands!! Amazing idea. It's like a rumba for your counter.

Thanks for the encouraging words! This is very much a thing in progress as right now it doesn't even have a brain. (I submitted this as a concept prototype for the Countertop Challenge contest.) The next version will have much smaller motors (with higher gearing so it will move more slowly), and downward looking overhang sensors to detect the countertop edge. It will also have motor current sensing so it can tell if it bumps into something and then reverse direction. Also in the plans is a wall-wart charging station with a bracket that holds the Counterbot right on the wall for charging. Because you'd periodically move the bot to different disconnected sections of countertop, a single docking/charging station might not work out too well.

Inventive idea, I hope all the features end up working, I'd love to have one of these!

good job but i read in the countertop challenge:
"Designs could be purely 3D printed accessories, with no additional components; or devices that are powered by your wall outlets or plugged into WiFi enabled, USB ports"

I believe the description you quote is mostly describing the range of designs possible, rather than a restriction on what can or can't be used. Under the contest guidelines on the firstbuild.com web site, it states: "Designs can have components that are not 3D Printed, such as sensors, fans, batteries, etc."

Very cool, but would the final product be able to identify between the edge of a counter and deep grooves between countertop tile?

Also, what's the effective UV life of that light? How many hours of use before it's just another bulb?

Thanks! It should be fairly easy to distinguish between the tile grooves and the counter edge using downward looking optical retroreflective sensors. As for the bulb life, I've seen numbers ranging from 6000 to 9000 hours, depending on the quality of the bulb. Ideally, for a real product, you would work with a UV lamp manufacturer (like, say, GE) and get a bulb designed for this application.

WANT!!! Make this thing it sounds super cool!!!