The Connector Contingency

Equipment
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I like to wire my sabers in such a way that they can be taken apart and fixed. I try to avoid using glue as much as possible, and most or all of my wires have connectors, if I have room for it. As with wires, connectors take up more space than it would first seem, and finding good small connectors is somewhere between hard and impossible, but here is a summary of what I have found so far.


Left-to-right: JST, Deans, picoblade, brickstuff

JST Battery connectors

This are fairly large, but if you buy a pre-wired battery, this is what you get. The datasheet says they are rated for 3A if I remember correctly, but Iā€™ve tested mine up to 20A. (At that point they get fairly warm though.) These connectors are polarized, so itā€™s not possible to hook connect them backwards. (Unless you wired it wrong.) These connectors are crimped, not soldered, and the shroud keeps all the electrical part insulated so there is no need for shrink tube or anything like that. I often incorporate slots for these connectors in my chassis designs:

Deans connectors

These connectors claim to handle 20A, which they do, but there is no headroom. Basically they handle the same amount of current as JST connectors in actual measurements. Unlike JST connectors, these are meant for soldering, and you need to shrink tube the connections. They are slightly smaller than JST connectors, but that advantage goes away when you add the shrink tube. Personally I prefer JST over Deans connectors.

Picoblade connectors

These connectors are often called ā€œmicro-jstā€ connectors. But thatā€™s wrong, because they are not made by JST. Last I checked, JST doesnā€™t even have any
connectors with 1.25mm pitch. These connectors are rated for 1A, but can probably handle a bit more. They also come in mult-pin configurations. I like using two-pin connectors for speakers, and 3-pin connectors for accent neopixels and buttons. (One for each button, and one for GND.) While itā€™s possible to crimp these yourself, itā€™s fiddly and the tools are pricy, so itā€™s actually easier to just buy them pre-crimped. There are also kits that come pre-crimped, but the metal bits at the end havenā€™t been inserted into the housing yet, which is really cool if you want a connector with more than three pins.

Brickstuff connectors

These are hand-made 2- and 4-pin connectors. They are probably the smallest option Iā€™m aware of, but I havenā€™t used them for anything myself. They are not polarized, and Iā€™m not sure how much current they can carry. Also, the connection is not locking, so itā€™s possible that they could disconnect. That said, if you want small, this might be the right choice.

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Good topic idea! Iā€™m down to read what works for you. Iā€™ve always used JST stuff in the r/c hobby and with sabers Iā€™ve had the concern over connector melting due to the draw. Iā€™ve seen them get warm to where a pair got so hot the pin and receiver melted out of the connector. That was where there was airflow, sabers definitely lack that. *Thereā€™s some phenomenal Mil-Spec Drone stuff but I donā€™t have a catalog to reference.

Side topic, Picoblade? As in Pico-Scope stuff? [Walks out to shop and plays with his Pico Scan Setup that is the best investment ever besides a hammer.]

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Wow! I stopped using JST connectors in favor of Deans because I was afraid of the current draw. The deans connectors were suddenly being used by TCSS on their high amp discharge batteries and I assumed it was necessary. I guess not!

I use the 5 pin Pico connectors for accent strip/speaker hookups and they work great once you shave down the little locking connectors, which can get stuck and cause a yoinking situation during frequent disassembly.

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The JST connector shown above is RCY: https://www.jst-mfg.com/product/pdf/eng/eRCY.pdf

The Picoblade is probably knockoff of a Molex PicoBlade: https://www.content.molex.com/dxdam/5c/5c20cf0c-dc16-4dca-8b42-a3ce2f6e0bce/987651-3691.pdf
JST makes GH connectors, https://www.jst-mfg.com/product/pdf/eng/eGH.pdf, which also have a 1.25mm pitch, so the picoblades are confused as GH, giving us the name ā€œJST micro connectorsā€. The cheap picoblades knockoff I have purchased are not very reliable, especially the 3pin and 4pin. The 2pin connectors seem to work alright. Purchasing the Molex assemblies form DigiKey or Mouser cost about 10 times as much as the knockoffs, so throwing out the bad one from a set of ten still works out.

1 Like
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Thank you for sharing this post, I can learn a lot from it. I bought some Picoblade connectors too, And Iā€™m planning to use them with speakers and switches. One thing I am not sure is about the GND wiring. My question is could I use 3-pin Picoblade connectors for two switches wiring? Two ā€˜+ā€™ switch poles go to button1 pad and button2 pad separately.
. Two ā€˜-ā€™ switchā€™s poles wiring in series go to the GND pad individually. (Do I need to connect switch GND to battery ā€˜-ā€™? )

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Yes, you can use a 3-pin connector for two buttons.
One for GND and one for each button. Your description is sort of confusing though, so Iā€™m not entirely certain you have it right.

GND and battery- are connected inside the board normally, so it doesnā€™t matter which one your connect to.

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Thank you Prof~ I will soon start the build.