Best magnetic Micro USB cable for controller?

Does anyone have any recommendations for magnetic MicroUSB cables? Thanks!

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nevermind, i found one. just wasnt looking in the right places lol. If you are wondering, this is the one I ordered


Our organization tried using magnetic USB cables for a short time, but found problems with metallic grit (from grinding in the lab, most likely) getting on the magnetic connection. We’ve since switched back to regular cables. Just be aware that this is a known problem if you cut/grind steel parts.


I cut all my pieces somewhat far away from the field do it think I’m ok :). would cut metal rub off onto the field? Thanks for the warning

A robot built without any bearings, for example, could grind metal shavings onto your practice field or onto a competition field. I don’t know for sure where the metal dust would come from, but it sticks really well! It took compressed air or sticky duct tape to clean the shavings off the contacts occasionally…and then finally we all gave up. My kids and I still use the cables on our cell phones (since we have a couple dozen of them), and I still find myself cleaning them occasionally.


Another problem we found when we bought magnetic USB cables was that the USB port on the V5 brain is very close to the battery connector. With the added width of the magnetic connector (or at least the one we bought) compared to a normal cable, there wasn’t enough clearance to connect the USB cable while the battery cable was connected.

We ended up buying short micro-usb extension cables (example) instead, that way the USB port was in a more convenient place and we were wearing out a replaceable component rather than the port built in to the brain.


I bought a couple dozen of these from Robosource: Now we have to get the students to use them!


i connect my usb cable to the controller for ez coding

The micro USB port has to be the worst port ever. No wonder people want alternative solutions.

The thing is so small that it is hard to determine which side is the rounded side sometimes. You’d think that you’d have a 50/50 chance of getting it right the first time though. I’ve found that is not the case however. In reality, it is only about a 10% chance of getting it right the first time, about a 40% chance of getting it wrong, about a 30% chance of getting it right but thinking it is wrong so you try it the other way and it is wrong so you have to got back to the first way. And about a 20% chance of getting caught in an infinite loop doing this over and over.

Also, why is the brain and controller opposite? On the brain the rounded side is up/on the controller the rounded side is down.


yea heres to hopeing usbc soon


I highly recommend using a short USB jumper if a team continues to plug and unplug the V5 Brain. The cable can be marked with a paint pen on one side to prevent flip/flop confusion, it reduces the wear and tear on the USB port, and it makes it easier to connect if the main port is hard to reach on the robot.

It’s much cheaper to replace a cable then to send a brain in for repair.


thx :slight_smile:

Just a heads up, we weren’t allowed to use them at state competition - still helpful for practices and cuts down on damaging ports. Evidently the RECF denied the use of then when I questioned the inspection crew. And yes, careful of metal grit someone else mentioned.

Where do you send brains in for repair?

Vex. They have a warranty program and a replacement program. See the support portion of their website for details.


This Q&A from Turning Point confirmed that it was OK to leave extension cables in place at tournaments. (and I would read this as applying to the magnetic cables as well – what is a magnetic cable but a very short extension?)

Of course, previous seasons’ Q&A responses do not automatically carry over, but given that no Q&A has asked the same question in a later season, and the underlying rule (now numbered R13) hasn’t changed in a way that would prohibit leaving the cables in place, I don’t see any reason to prohibit a team from leaving such an extension cable/magnetic nub in place.

Unless you’re at worlds, your questions to the inspection crew are almost certainly not being run by the RECF – the highest they would go is the event’s head inspector or head referee (technically two different roles, but closely related, and filled by the same person at many events).


Thanks for the information. It seemed unreal that they could check that fast, so I will keep this information handy for future reference.

sorry to revive and old topic, but are they any good? my team dont want to end up buying a rubbish one so just wondering.

They are ok, there might be better ones on the market, but it works

I have these
they come with MicroUSB and iThings. Pretty happy with them after a months worth of use.

Presently $6 for a 3 pack, so at $2 each they are a great buy. And not a big deal if they get lost.

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