Heat Duct Rover Explores Stink, Rescues Flashlight

It all started with a bad smell coming from the heat register. [CuddleBurrito] recalled a time when something stinky ended up in the ductwork of his folks’ house which ended up costing them big bucks to explore. The hacker mindset shies away from those expenditures and toward literally rolling your own solution to investigating the funk. In the process [CuddleBurrito] takes us on a journey into the bowels of his house.

Version 1.0 of his investigation tool was a flashlight and cheap web-cam attached to the end of  tape measure. Pushed along into the duct and monitored on his laptop, he got great video – right up to the point where his rig got snagged on something. A few tugs left him with a ruined camera and a stranded flashlight – his favorite! The mission quickly turned from investigation of the smell to recovery of the still-lit flashlight. With the clock running, and realizing that his rig needed wheels to avoid getting snagged, he whipped up a quick sled from tongue depressors and hot glue, and used a stout cardboard tube as a roller. Decked out with another flashlight, another web-cam, and a small servo with a zip tie finger, [CuddleBurrito] plunged the depths yet again, intent on retrieving his favorite flashlight by its lanyard. The rescue starts at the one minute mark in the video below.

Sadly, once the mission switched to a rescue, the source of the stink was never located. We suspect curiosity will get the better of [CuddleBurrito], though, and when it does, we’d like to see what mods he makes to this rig to mitigate the odor.

32 thoughts on “Heat Duct Rover Explores Stink, Rescues Flashlight

  1. If he’s running USB for the camera, it shouldn’t be too hard for him to put a small USB hub on the end of his contraption to plug in both the camera and some LEDs, and eliminate the risk of losing a flashlight.

    1. I did something similar to that to route some cables through my vent once. Sadly, I didn’t aim the camera down enough to see the vertical section of vent my rover fell into. I had to use the emergency recovery string I had tied onto it to get it back.

  2. Why not make this a competition thing?

    We have all sorts of robotics competitions from autonomous vehicles to fighting robots, but “closed space explorers” seems to be lacking at the amateur end (of course they’re used in pro applications like pipelines etc).

    Give them a 3D ductwork to negotiate and retrieve a prize…think of the climbers, data feeds and spidey-web-shooters that would be invented. Bonus points for autonomous (a 3D maze solution) operation.

    Are you listening Sparkfun et al.?

    1. Is sounds like a neat competition!
      I’d even suggest different levels of duct work:
      Flexible tubing duct
      Rectangle duct
      Round sheet metal duct
      *Bonus round: vertical travel & maximum airflow it can withstand (say the HVAC kicks on)

      If you want to see some crazy pipeline tech look up oil pipeline PIG designs. Even though most are raw mechanical they have some wild multi axis tracks/rollers/bearings to get around bends corners without pinballing the internal structure.

      1. Took your advice and did some Googling. But I was very disappointed – none of them looked like they had a seat for a certain British spy and his lovely companion. Nor much room to attach a bomb.

  3. I thought I had a smell in my hvac – attached a cheapish IR Wifi webcam with a rigged AA batteries and duck-taped it to a shop-vac hose. turned out it was one of the main 150 amp breakers right above it – only smelled when the hvac was on – the breaker was getting so hot that my amp meter got stuck to the wire when I got a reading – it was pulling less than 9 amps

    the fun part was having to pull the meter to replace it and ended up twisting the clear cover of the meter while it was still attached and releasing all the anti tamper things into the air – oops – managed to get it straightened out.

    It’s a smart meter so the power company came to check it out a few days after that but they never said anything about it

    fun times…

    1. Yes. There are exceptions, occasionally you may have some; pipe, tubing, copper work line, develop condensation. Water drips on wood or paper and various bacteria/molds/fungi form and they fight it out for over 1-2 seasons. The funk smells almost identical to meat putrefaction.

  4. As a former HVAC tech I’d suggest looking inside your air handler and the plenum on top. The whole “explore the ductwork” thing is awesome but it’s likely the problem is in the air handler.

    1. Yep, you’re far more likely to find something closer to the unit. That said, if you just moved into an apartment, check behind the return air grill. I only say this because many years ago an apartment complex was incredibly crappy to us and after we’d complained about their lack of maintenance, they decided to evict us, so I left a dozen eggs in their return and then turned off the heat so the stink wouldn’t happen until long after we’d left(and they’d have a much harder time figuring out where it came from since it was in the return). I’ve told a lot of people about this so at some point I expect to hear someone actually did it.

      1. Pity you couldn’t sneak a deep frozen whole fish under the fake ficus tree in the front office. That would have been justice. Commercial run apartment properties just like any other big company. Sorry for the next tenant(s) though, they might have been decent people.

        1. It’s true. And unfortunately the landlords aren’t going to give any more of a shit about the poor next tenants and their egg-stinking apartment. You picked the wrong victim, Herr Weiss.

  5. I wanted to build a robot that could go throughout my ducting, most of it is round and some of it goes straight up and down. Love to be part of a build that would do a DIY project that remote controlled robot with camera could go in your ducting.

    anyone interested?

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