The best Can bus connectors

After years of struggling with our can bus we found These lever nuts on [Amazon](Lever Nut Wire Connectors, 28-12AWG Butt Splice Terminal Wire Connector Box (SPL-2, 28PCS) https://www.amazon.com/dp/B07V4LD144/ref=cm_sw_r_cp_api_glt_fabc_YWYcGb47MC7XD?_encoding=UTF8&psc=1) last year that worked out great. No crimping or Soldering and
Still gives you the option to swap components in and out.

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I appreciate you posting a product that you’ve found to work. IMHO, I’d rather stick with the inventor’s product:

https://www.amazon.com/Wago-222-412-LEVER-NUTS-Conductor-Connectors/dp/B003K0J4IQ

Your appears to be a Chinese ‘pop up’ company and frankly, I wouldn’t trust the safety or the quality of their products. I would guess that they do not have the rights to produce a wago clone, either. I try not to support companies like that whenever possible.

In fact, you can get the actual Wago product from Andymark, in serveral different forms.

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The difference is you need two of the WAGO 221 series lever nuts for every CAN connection which is pretty bulky (especially without mounting holes, those connectors just flop around). The OP’s connector has two separate poles, so it’s pretty compact - two wires in one side, two wires out the other side.

Here’s a version of the same connector with mounting holes [Edited]
Here’s another that clips to DIN rail
This one would serve three separate CAN devices if you are willing to ignore the wrath of CAN topology purists :slight_smile:

Note, I can’t vouch for any of the above in FRC applications, although I did use the last one to install some undercabinet low voltage lighting.

[Edit] - apparently 3D printed WAGO 221 holders are also a thing, so that would answer some of my points.

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We use these: https://www.amazon.com/gp/product/B07QKBKNC1/ref=ox_sc_act_title_2?smid=A31G33MT63S07E&psc=1 (JST-SM2.5). Requires crimping, but they lock, haven’t had a can disconnect since switching to them. And a whole of a lost less bulky then lever nuts. I like having lever nuts around for quick fixes and diagnostics, but I wouldn’t use them as a permanent solution.

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As mentioned above that style of lever nut is pretty slick. I wish Wago would make something like that in the new style, but they seem to be dead set on emulating the wire nut experience, which happens to be a pretty poor can experience imo*. (bulky, facing the wrong direction, not really meant for that gauge, etc)

Well, really, I wish TRRS/TS can was a thing but that’s a whole different worm can.

*edit: I take that back, everything about wirenuts is garbage, period.

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Yep. I absolutely see the use case, and don’t blame the OP in the least for using them. I wonder if WAGO just doesn’t see enough business in the end-to-end design like that.

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WAGO 221 (and 222) is really optimized for home wiring – it can work well with smaller wires, but it’s not designed for twisted pair. If you open up too large a loop of untwisted wire, it can cause noise problems. This is more of an issue at higher data rates, but the best practice is to minimize the number of connectors and then probably to use “Molex” style connectors. Using larger sizes will be easier, and going all the way up to a pair of “bullet crimp connectors” should be OK (just keep both sets close together and don’t untwist more wire than necessary).

I did find these – but as soon as you take out crimping, wire-to-wire connection options get cut down pretty dramatically. To be clear, I have not tried these (but they seem like a better option, provided they prove to be reliable). I’d stick to trusted brands (like WAGO) if you have any doubt though.

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I did find these

Those connectors you linked are better used as paperweights than on electrical conductors of any kind, other than for highly temporary testing purposes. I’ve had many melt on me under very moderate loads, and their wire retention is poor at best. Avoid at all costs.

I’ll second Rohit on JST-SM2.5

We use these: https://www.amazon.com/gp/product/B07QKBKNC1/ref=ox_sc_act_title_2?smid=A31G33MT63S07E&psc=1

We are in love with these connectors for CAN. Yes, you must crimp them. No, they aren’t the easiest crimp to learn to do well. But I’ll be darned if one ever fails on me.

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I doubt CAN signals are going to melt anything, but poor retention is a non-starter.

For anything important, we solder the CAN wires, and heat shrink them.

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I also doubt they would - just a comment on their (lack of) quality from my experience. I would definitely not allow those connectors anywhere near robot power wiring. Not even custom circuits. :fire:

Also Wago-esque, but these are really awesome and robust for CAN bus, we also use them for extending lower gauge wires. Been using them the past few years without issue.


Also

As a general statement, only do this if you really don’t plan on changing what’s connected quickly, or if you don’t expect to need to repair them where they’re located

As was mentioned earlier, those aren’t official WAGO products and WAGO unfortunately doesn’t make an official version. I don’t think they’ll be too bad if you’re just using them for CAN, but just keep in mind that they won’t be the same quality as the genuine product that’s had all the certification and testing and such.

Adjusted above, thanks for the correction!

Out of curiosity, do you all cut off the molex connectors that exist on your motor controllers to interface with these, or do you use the other options for jumpers? I am aware that not all CAN devices have built-in-ends, but most of the ones we use do.

We made custom PCBs last year for CAN cabling. CAN purists look away. Sticking with punny PCB names, these are the CANJunction (CANJunction junction what’s your function?)

They worked without any issues at our one event. There were cases in the shop where it seemed like the lever didn’t get a good grip on the wire, and would keep pulling out. So could have been some bad connectors. Not a bulletproof solution yet. But I did like how easy it was to drop in new components on the bus. They are designed to wire the main bus in/out on the 2pin pair connectors, then T off to up to 3 devices. The driver for this design was to allocate one PCB per drivetrain gearbox. If you have less than 3 devices in a location, leave a slot empty for later use.

If anyone wants to make their own, Gerber’s and kicad project files are here.

I’ve seen similar COTS products from CTRE, and Playing w/ fusion


In 2019 we ran these “T Tap” press on connectors through the whole season. They worked fine, no problems in matches, but I think the wire gauge or insulation diameter we had for our CAN cabling may have been slightly large and they didn’t always want to easily latch closed. Electrical team members liked them.
Again, we never had a problem, and I know there are other teams using them year after year. Just not personally a fan.


We used the SPL-62 for low current custom circuit branches off the PD board last year. Worked well, super convenient 10/10.

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I bought a handful of these inline lever nut clones. They are much bulkier than the aforementioned Wago 221 series (about 2x as large) but their inline nature makes them ok for FRC.

We tried soldering CAN in 2020, and given the variable nature of solder joints (and the inevitable forgetting heatshrink until after it’s soldered) and semi-frequent swapping things out we ended up with about half lever nuts in the end.

Going forward, I think properly ziptied-down Wago 221s are the way I will recommend CAN. I’ve had the pleasure of working with students from all experience levels, and neither crimping (the worst) nor soldering (usually fine) is ever as consistent as lever nuts. I like the 221 series because of their clear housing - this makes inspecting the joint very easy. If Wago came out with a small, clear, inline version of the 221 (something that looks like them back-to-back) that would be my recommendation for the future.

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Suck it up and do this, you won’t regret it.

Buy yourself some ts100 soldering irons and hook them up to drill batteries, the repair time is crazy fast if you dont care about nice hearshrink, and can do field side if needed.

Been wanting to try some soldering heat shrink, I’ve seen more and more teams run them.

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Every part of this sounds like a bad idea, both from a safety and a QA perspective.

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TS100s are supposed to be good irons, although I’m more of a fan of bench ones myself. It is common to power these from batteries.
Before I had a heat gun I would use the barrel of a soldering iron to heat my heatshrink. Worked fine.

That said, field-side, keep a pocketful of Wago 221 on the robot cart and some zipties and wire strippers. It’ll be easier than waiting for a soldering iron and you can fix it when you get back to the pit.

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