Cable Management

A project log for Fluffbug

Cheap four-legged insect robot

deʃhipudeʃhipu 07/31/2021 at 14:430 Comments

Cable management is a big problem when you have a moving construction with eight servos. It doesn't help that by default the servos come with relatively long cables, and this three-pin plug on the end, that is hard to replace without special tools:

Of course it would be best if you could just take that plug and plug it into the PCB, but then you need to do something with good 20cm of extra cable.

We brainstormed about this problem, among other things, during the hackaday prize mentoring session with Kliment Yanev, and he came up with an ingenious solution that just might work. Yes, you need to get rid of the default plug, and the spurious cable, but then you are left with the problem of either soldering the remaining cable directly to the PCB, or attaching a different plug. Turns out there are plugs out there that are very simple to attach, and quite popular and easy to get. Kliment suggested I can use the plug that is commonly used for the ribbon cables:

They have those blades in them, that bite into the cable when you press the tab on top, and make a secure contact. Furthermore, we are not increasing the price a lot, because you can use a single plug for multiple servos. Sure, this makes them harder to replace, which is a downside, but I think I can live with that.

Unfortunately, this also means we will need a PCB redesign — the way this plug connects with the cables, we will need a completely different pattern of pins for it. Oh, and we can't put the sockets for those plugs in the same place on opposite sides of the pcb, not easily, anyways, so I will need to think about where to best place them. But I like the idea and I'm going to give it a try.