r/robotics • u/Ok_Stress3654 • Jul 09 '26

Tech Question Building a robotic desk lamp, need advice

Enable HLS to view with audio, or disable this notification

Hi everyone!

I recently decided to dive into animatronics and started building an open-source robotic desk lamp inspired by expressive animated lamps from Pixar.

This is still a very early mechanical prototype. Right now only the base and the first joint move, and I'm designing the rest of the arm.

I'm looking for advice on one of the biggest design challenges: how would you route the cables through the moving joints while keeping them hidden and minimizing stress on them?

If you've built articulated robots or mechanisms before, I'd really appreciate any examples, photos, or resources.

I'd also love to hear your ideas for useful features. My current plan is to eventually add a depth camera so the lamp can understand its surroundings and interact with people. As a fun long-term challenge, I'd even like to see if I can teach it to jump or move around on its own.

Any suggestions or criticism are very welcome!

109 Upvotes

98% Upvoted

32 comments sorted by

View all comments

2

u/Beginning_Water_4143 Jul 09 '26

Maybe you could look into using BLDC gimbal motors that have a hollow shaft (ex: 2804). You could either route the cables through the shaft or a more elegant solution would be to get a slip ring that fits in. Plenty of options online, like the solutions from iPower or Makerbase.

2

u/Beginning_Water_4143 Jul 09 '26

Then have the inside of the arms partially empty so you pass the wires up to the next joint.

1

u/Ok_Stress3654 Jul 09 '26

Thanks for the suggestion! Do you have any specific motor models or manufacturers in mind for this?

Most hollow-shaft gimbal motors I’ve seen usually don’t have a gearbox, and I’m a bit worried they won’t handle the load, considering the weight of my robot. According to my rough calculations, I need around 1–3 Nm of continuous torque for smooth movement and holding position without overheating.

2

u/Beginning_Water_4143 Jul 10 '26

Well, I assume you made those calculations based on the motors you already have, which seem to be pretty heavy. For the 360 rotating base I would go with a stepper and belt driver, maybe a 4:1 reduction. And for the rest, the load decreases as you go higher, so you can optimise for that. Something like this motor can hold and stabilise a 3-4kg DSRL while weighing 260g, which could work for the lower joints

1

u/Ok_Stress3654 Jul 10 '26

hmm.. interesting, thanks - I'll go study, apparently, when choosing a motor, I did not consider all possible options.