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Show HN: I designed my own 3D printer motherboard

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21–30 of 41 posts

Re: Show HN: I designed my own 3D printer motherboard

#21

You did an amazing job. What I really like is the attention to detail that will facilitate cable management and repair. This is the weak point for most 3D printers: when you run them long enough and hard enough they'll break and you will need to replace parts. Depending on the brand of printer this can be hard, tricky or next to impossible without a complete teardown of wiring looms and such. Consider using a slightl…

I'm probably going to run Marlin just because it would be the first 3D printer I've actually made and I've heard it's more beginner friendly. I think Klipper also needs a dedicated host like a Pi which is a bit more overheard I don't want to worry about, but I'm open to exploring any type of firmware!

Re: Show HN: I designed my own 3D printer motherboard

#22
post #4

>This is one of the first PCB's I've ever created, so it might have some flaws. >4 layers That's quite the jump for a noob. Would you mind sharing how you learned to produce such advanced output so fast? I mean my first ~50 PCB we're still just 2 layers. Edit: nvm I just saw the journal.

For me, it helped me to look at open source hardware like adafruit's.

The Mini Sparkle is a 4 layer and available on their github https://github.com/adafruit/Adafruit-Mini-Sparkle-Motion-PCB

There are many more available at OSHWA : https://certification.oshwa.org/list.html

Re: Show HN: I designed my own 3D printer motherboard

#23

This is awesome! I'm in the industrial software / CAD space, so I have a rough idea of how painful and complex these engineering workflows can be, even though I don't design hardware myself. You might find it interesting to look into AI-powered PCB design tools for your next iteration. There are some cool tools popping up that can use AI to assist with the trace routing and layout, which could make the process much l…

Routing is honestly one of my favorite parts of making a PCB, there's something about the feeling of understanding exactly what each trace is doing that I find exhilarating.

The problem with most AI powered tools is that they don't understand the context of your board, which is absolutely crucial for routing. Like so-and-so trace could be switching really fast and an AI powered design tool wouldn't understand that and wouldn't route it properly. Or like power for example, different things have different power requirements and I feel like we're not at the point where these tools are referencing every datasheet on the planet to figure out trace/fill sizes and whatnot.

There's also some concepts I don't think these tools can wrap around quite yet. For example, minimizing loops, consistent ground planes, proper impedance control, and just all of these factors lead to an inferior board.

Not saying that humans are perfect and understand all of these too, I just feel like if you understand what's happening with your board, you can do a much better job.

At the end of the day, you'll be spending more time fixing the mistakes, which are actually pretty hard to spot without checking every single trace sometimes, then actually just routing it yourself, but maybe one day we'll get there!

I'd love to hear some other takes though ;)

Re: Show HN: I designed my own 3D printer motherboard

#24

This is awesome! I'm in the industrial software / CAD space, so I have a rough idea of how painful and complex these engineering workflows can be, even though I don't design hardware myself. You might find it interesting to look into AI-powered PCB design tools for your next iteration. There are some cool tools popping up that can use AI to assist with the trace routing and layout, which could make the process much l…

"... I have a rough idea of" and "look into AI-powered ... design tools" is a sad sentence to come across. This young individual spent time to learn complex things and implemented it into an actual useful physical thing. Why give this advice in the first place? To stop them from learning?

Re: Show HN: I designed my own 3D printer motherboard

#25
post #4

>This is one of the first PCB's I've ever created, so it might have some flaws. >4 layers That's quite the jump for a noob. Would you mind sharing how you learned to produce such advanced output so fast? I mean my first ~50 PCB we're still just 2 layers. Edit: nvm I just saw the journal.

For me, it helped me to look at open source hardware like adafruit's. The Mini Sparkle is a 4 layer and available on their github https://github.com/adafruit/Adafruit-Mini-Sparkle-Motion-PCB There are many more available at OSHWA : https://certification.oshwa.org/list.html

I also did forget to mention, but this project is OSHWA certified too :D

https://certification.oshwa.org/ca000068.html

Re: Show HN: I designed my own 3D printer motherboard

#26
post #11
post #3

Really cool. I found myself traveling recently and missed my 3d printer. There were a few neat things I could have done if I had a printer in a carry on. It would be kinda awesome to have a self contained 3d printer with a battery to take wherever I go. If you're near a harbor freight, they have cheap rugged cases. Maybe design around that form factor, since they're easy to get?

https://www.jeffgeerling.com/blog/2024/positron-upside-down-... and here you got an interesting form-factor

I was thinking the same, thanks for linking to it. Their github has gone quiet in 2025. Is Positron still viable concern?

Re: Show HN: I designed my own 3D printer motherboard

#27

Why all those heat sinks? Power electronics are getting very good these days with low RDS-on. Have stepper drivers not kept up?

Sadly not really. I think we're only a few years away from BLDC servo motors taking over from steppers in 3d printers. Ideally control algorithms for them would go into the MCU so there is proper force feedback too - ie. The system will know that there is an extruder clog by the increased extrusion force, or even set print speeds to be 'the fastest you can follow this path' rather than a fixed number of mm/sec. Ie. I…

I completely disagree. BLDC control is not far from AC-servo, and they are insanely cheap nowdays

https://www.omc-stepperonline.com/ac-servo-motor

These are EtherCAT AC Servos for a couple hundred bucks, Any small cnc project that uses steppers/small bldc is a joke IMO

Re: Show HN: I designed my own 3D printer motherboard

#28
post #3

Really cool. I found myself traveling recently and missed my 3d printer. There were a few neat things I could have done if I had a printer in a carry on. It would be kinda awesome to have a self contained 3d printer with a battery to take wherever I go. If you're near a harbor freight, they have cheap rugged cases. Maybe design around that form factor, since they're easy to get?

You'd need a pretty substantial battery on account of how much heat it takes to melt filament. Even the Bambu A1 Mini uses ~150W while heating the hot end. I like the idea of a portable printer, though.

It's actually not the hotend heating that's the largest power drain, it's heating the large heat bed. Bambu Lab is introducing firmware features to more slowly ramp up the heat, but I don't need if that could happen slowly enough to not drain a battery.

Re: Show HN: I designed my own 3D printer motherboard

#29
post #13

I was confused by the prominent use of the word "stepstick", not something I was familiar with even though I try to expose myself to quite a lot of 3D printing material (having one is still more like a bucket list item, though). I think the term is/was originally a product name for a small, rectangular module with a stepper motor driver on it [1] from 2012. Then it seems the term has been made more generic, with upda…

I think the thing about StepSticks is they all have same (or very similar) pinout - so as long as board is designed for generic "stepstick", you can plug your favorite kind.

Earlier journal log entries mentioned TMC2209_SILENTSTEPSTICK, but most recent schematics removed this designation. Seems like an oversight.

Re: Show HN: I designed my own 3D printer motherboard

#30

This is awesome! I'm in the industrial software / CAD space, so I have a rough idea of how painful and complex these engineering workflows can be, even though I don't design hardware myself. You might find it interesting to look into AI-powered PCB design tools for your next iteration. There are some cool tools popping up that can use AI to assist with the trace routing and layout, which could make the process much l…

Routing is honestly one of my favorite parts of making a PCB, there's something about the feeling of understanding exactly what each trace is doing that I find exhilarating. The problem with most AI powered tools is that they don't understand the context of your board, which is absolutely crucial for routing. Like so-and-so trace could be switching really fast and an AI powered design tool wouldn't understand that an…

You're right that physical context is crucial. However, mathematically, PCB routing is a Graph Theory optimization problem that falls into the NP-hard complexity class (related to the Steiner Tree problem). Traditional solvers rely on heuristics (like A* or annealing) because finding an exact mathematical solution is computationally intractable for complex boards. My point about AI—specifically Graph Neural Networks (GNNs)—isn't about bypassing the learning process. It's about using statistical approximation to handle these high-dimensional topological constraints more effectively than human intuition or standard heuristics can. It's not 'lazy'; it's applying a modern computational lens to an unsolvable deterministic problem.
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