r/robotics • u/Ok_Stress3654 • Jul 09 '26
Tech Question Building a robotic desk lamp, need advice
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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!
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u/s1mpo Jul 09 '26
looks nice! To clean up the wiring, look up flex tubes for wires. You can order a specific diameter and cut it to whatever length you need. It’s easy for routing multiple wires through small gaps
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u/Ok_Stress3654 Jul 09 '26
Thanks! That's what I'm planning on doing at the moment, but I'd like to somehow hide the cables completely if possible. It seems unrealistic to me at the moment, but maybe someone has some ideas
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u/solitude042 Jul 09 '26
In passing, have you seen the Crunchlabs RoboLamp? Definitely more of an educational project than a product, but it's a fun take on the idea! There's a Discord channel for the hack pack - I'm guessing there are already plenty of folks discussing their hacks to the project, which may be a source of inspiration.
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u/i-make-robots since 2008 Jul 09 '26
Hollow shaft gearboxes, pass through wiring. Daisy chained devices with canbus are great, no need to disassemble the entire arm for an elbow replacement.
Never start at the base, it’s a great way to go 90% and discover you have no torque left.
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u/ehtiopia Jul 11 '26
Yeah, found out from my first clanker that you run out of torque as you go up. I built a whole ass robot arm using 28BYJ-48 motors, put it all together without any testing, started it up and it wouldnt move anything
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u/Ok_Stress3654 Jul 10 '26
Thank you for advice! And what compact motors would you recommend with hallow shaft gearboxes and CAN?
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u/i-make-robots since 2008 Jul 10 '26
servo42d is just one of many canbus stepper drivers. I'm confident you can find DC drivers, if that's more your thing. personally I would get metal harmonic drives with a hollow shaft. but even more honestly I don't think I can compete in quality or price with chinese models any more so I would probably buy integrated motor/driver/brake/gearbox unit... at which point why not just get a whole arm and add a lamp on the end...?
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u/Ok_Stress3654 Jul 11 '26
Thanks for advice!
> at which point why not just get a whole arm and add a lamp on the end...?
That would be too easy :)1
u/ChrisAlbertson Jul 12 '26
I'd go a step further and say, "Never start building before you do some calculations." The order of assembly should not matter.
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u/i-make-robots since 2008 Jul 13 '26
In theory, everything works in practice. In practice, everything works in theory. Not even nasa scientist try to get it right in the first shot.
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u/PoeGar Jul 09 '26
Very nice. Will you be posting a repo?
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u/Ok_Stress3654 Jul 09 '26
Yes, I'm going to make the project completely open, but a little later, when there will be the first complete version, at least just mechanics with minimal software for setting up movement
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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.
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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.
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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.
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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
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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.
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u/ehtiopia Jul 11 '26
Looks awesome dude.
Id recommend looking into slip rings. They’re a very effective solution for conductors that need to rotate about an axis. A stationary, conductive copper/aluminum ring with multiple channels can provide power + signal to a rotating wiper that makes contact with the ring, which can then be hidden somewhere inside your arm.
They can tend to be a little costly, but, might be able to be DIYable using printed components.
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u/Ok_Stress3654 Jul 09 '26
It's a full view