Occasionally I’ve had to repair Chinese hilts with Proffieboards from places like LGT, ArtSabers, DamienSabers, Nexus etc. etc., and occasionally I’ve been surprised to see in some of those sabers that they’ve only used 30 awg wire for the positive and negative between battery and neopixel blade.
This doesn’t apply to all budget hilts, and I can’t remember specific examples, but obviously we all know that 22awg is normally recommended for those power lines. But of course we also know that budget hilts like these are built to a price and manufactured as quickly and easily as possible.
But 30awg seems like a stretch to me, in hilts that otherwise look to have been reasonably well thought out.
For all their faults, I would have thought that any manufacturing factory would be well aware of the science and physics involved when specifying wire grades. And since it’s not in any company’s interests to have wires melting in their products, it got me thinking, is the 22awg spec that we all use and recommend actually overkill?
i realise there are variables like wire length, heat disippation etc, but 30 awg feels too thin for those factors to mitigate enough. And yet I’ve never seen a hilt that actually has melted wires from normal operation (unless they’ve been helped along by a short or other fault).
Personally I’m always happy to over-spec rather than under-spec, and in a custom build, that belt and braces approach is, I think, the correct one, which will hopefully ensure our sabers keep working for decades to come.
But is China onto something?
Is 30awg safe or inherently dangerous?
Just curious to hear people’s thoughts on it.
When I first starting building I had a zero budget and no work shop. Well, I had a budget but after buying two boards and a soldering station it was gone. The wires I wound up using on my Nano Biscotti V2 were harvested from the inside of networking cables. Literally trash. I have no idea what gauge they were but they were small. Of course that’s pre neopixel with 5A discharge batteries. I got away with that for a while. But to be fair, those junk wires lasted a long time in those old in hilt builds.
Trying to move over to pixel blades created issues with my original style of scrap building. I tried reusing the batteries and they’d trip the protection circuit on my first Proffie (I recall @MegtoothSith in the forums saying: lemme guess you’re trying to use an battery from the TCSS…), and everything was glitchy. But a few years and salary steps had passed (that’s what we call them as prime, I mean elementary school, teachers) and I was able to buy a few more tools. It was following the wiring guidelines that cured the rest of my problems.
So I think you can build with small wires, but only if you don’t mind them breaking or burning. They’re the first place to look after the battery of you have them and your blade is acting odd. And if you have a good installer and don’t mind paying twice for your saber, why not.
If they’re on to something, it’s that the sabers they sell may not be expected to have a long lifespan as trade off for cost.
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I dont know that 30 awg is dangerous per se, but you are certainly not allowing full amperage through. When I started building in hilt cree led sabers, I used 30 for everything. While that can work for pixels, and my earlier pixel installs used 30, you get brighter, better results using heavier gauge wires for power supply to and from battery and blade.
Im currently rebuilding one of my 2017 TeensySaber commissions, it used all 30 ga. It wont be going back to customer like that. Pushing amps through too thin a wire will heat it up, and cause copper to become brittle, and flexing wire can cause breaks. Its best to stick to reccomrndations on pixel sabers, for brightness. and endurance. I have seen 30 on many of the lgt offerings, Im not surprised. Ive also seen on an earlier legobrick saber, tge Chinese mfr did not bridge 2 Mosfet pads for main blade power, resulted in a slightly burned fet, and massively diminished blade brightness. I fixed that one for smoothjazzamily aka Sarmiento.
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There is no hard rules when it comes to wires, there is only ohms and watts laws, which you can use to calculate exactly how much power you will lose in your wires, and exactly how much heat your wires will need to dissipate.
One sometimes overlooked factor when it comes to wire thickness is the length. The shorter the wire is, the more you can get away with. A 5-inch wire will have 5 times higher resistance than a 1-inch wire, and if your wire is under-sized, that matters. (This is in fact why BATT- is close to the FETs on a proffieboard.)
If you’re planning to use under-sized wires for some reason, I recommend doing the math. If the math suggests that your wire will be putting out more than a watt of heat, then don’t do it. (0.1W might be ok though.)
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