Spanner Rescue Robot

So, as with most of my projects it started out as a joke that got out of hand…

Our workshop is three cargo containers welded together, sat on breezeblock plinths, but until recently there was a gap in the floor. Just big enough to swallow a 13mm dropped in the worst possible place. I cursed my bad luck, and as I was in a hurry working on a project, but kinda wrote it off. Last christmas I had the daft idea to throw together a robot to head under the containers to rescue it however.

It started off with an old tracked RC toy I had, but that turned out to be way too fast, instead I settled on using a Rover 5 chassis I bought years ago and never did anything with.

Taiko Velocitrax, with StereoPi board and LIDAR.

Thankfully the “plate” I designed for the Velocitrax was intended to be able to be used as the basis to rapidly prototype robots and fit on the Rover 5 chassis quite happily.

Velocitrax and Rover 5 chassis, along with the robotics “plate”

Sadly the real world returned all too soon and I forgot about the project, only to rediscover it this Christmas with an extra year of experience under my belt and less burned out that last year. Relatively, anyhow :sweat_smile:

Fast forward to this Christmas…

I thought I’d try building out a Unity based ROS controller using their ROS TCP Connector, it works a treat but I think this would be a solution for a dedicated robot rather than hacked together robot. For that I’ll be looking at writing a Joy message publisher for Foxglove Studio as I think it’ll be easier than developing something myself from scratch.

The hacked together version of the bot, rather than stereo cameras I have one facing forward on a tilt mechanism and another facing to the rear. The LIDAR is just used to give warning in case I’m about to drive in to one of the lower hanging beams that support the floor of the container.

I sent it on recon and actually found the damn spanner!

and because I’ve got attached to it, I’m rebuilding it before putting a gripper on the front and sending it back under the workshop to retrieve the spanner!

Currently finishing the design for the gripper, hopefully will be sending it on another mission over the next few days.


Hardware is (hopefully) done! I’ve only to update the code to control the extra servos now, should be ready to roll tomorrow!

Good news/bad news! The good news is I was able to get the controller working and sent the bot under the workshop on it’s mission, the bad news is I foolishly 3d printed a part that acted as a servo horn for the main boom. At one point I put the boom down far enough it lifted the robot and promptly scrubbed away the teeth attaching it to the servo and we had to suspend play!

This is a valuable lesson that I’ve apparently failed to learn on countless projects, somehow I think “this time it will be different” and once again fail to learn :sweat_smile:

Part updated and currently printing, fingers crossed this time we’ll be triumphant!

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I’ve enjoyed reading through this, and can’t wait to see the finally-recovered spanner. Thanks for sharing!

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Boom arm upgraded, a wiring issue fixed, all charged up and ready for another attempt tomorrow!


Oh my god, I can finally rest! :rofl:

I was recording the whole thing for posterity, I’ll be putting something together next week probably and will share a link here for those who want more details on the madness this involved!



Guilty as charged! There’s no rabitt-hole too distracting I can’t fall down…

I use this gif to explain things to my family. Eventually they will understand the curse.

I had to share this screenshot because it’s very cool…
I’m giving an online talk to a STEM group in Lagos tomorrow and thought I’d give a live demo of the spanner bot in it’s natural environment. I’ve managed to get one of my other robots, NE-Five, to act as a camera-bot!

Definitely going to have to look in to using ROS for a distributed camera system for live events I run, I think this could work quite nicely!

A big shoutout to Foxglove Studio for making this really easy to set up custom views like this! No affiliation, I just think it’s a great tool :slight_smile: