Hi, so this year our team tried using a different connector between CAN wires.
They worked pretty well but the only problem we faced was that sometimes they didn’t touch the wires themselves and so we had to position them in a specific way or put pressure on them with zip ties
We are planning to search for a different connector this year and I was wondering what connectors does you team use?
(Pls provide a link/exact name of the connector)
We have used the CAN Weidmuller connectors from CTRE with good success. They come in a 5 pack and you can disperse them around the robot since each one has mounting holes of its own.
The price seems a bit high to me but it’s never failed us once so for the $4 each that peace of mind is worth it. There are other teams who have made their own versions of this. I don’t have a number off hand but I have seen it! I know that 217 (ThunderChickens) have done a Star Bus Topology connection before and they showed me at their old lab when I went for a visit once.
Otherwise we have also used the 1 to 1 wago lever nuts , but these are not a great long term answer. These could come loose easier than the Weidmullers. I recommend the Weidmullers still and just remember to use Ferrules as well!
We use the Inline CAN Bus Clear Lever Nuts from West Coast Products. They work very well and give a solid connection, like any WAGO style connector. That said, we’ve also started to just solder and shrink tube critical connections (like the drive system CAN loop) since even the best connector can come loose, especially if it’s hit. We only do this where it’s unlikely or impossible that we’d need to change things quickly (like the drive system, where replacing a Falcon takes time anyway) and use the lever nuts anywhere that’s more likely to need to be disconnected quickly. We did this for our arm and end effector this year, since we might need to removed or disassemble it in a hurry at competition (as indeed we did when the end effector got damaged during a match).
Edit: I should note that our drive system is on a separate CAN loop run through a CANivore. That’s why soldering it but not other CAN connections makes sense. Since it’s isolated, a failure in the other loop won’t affect it.
We have used wago and had poor luck with them, this year we soldered a lot and had some xt30s. I think we are going to move to more xt30 connectors. Just remember if you are putting them on a device, each device should have one male and one female xt30 connector.
I hate the bulk that comes with connectors, especially for CAN, so we just solder everything together. We bought some ditto connectors to try this year but didn’t have the time to properly test them enough to try and put them on a competition bot. Any connector that I would use would have to be locking, and not use any lever-like way of connecting the wires, as those can vibrate loose.
We switched to wagos this year and have had good luck with them
We use these
smseace 50 Pcs Lever Wire Conductor Compact Connectors Button clamp Quick Terminal Block for 2 Circuit Inline Splices 28-12 AWG https://a.co/d/ixpmRi3
What is your plan for replacing one at Competition? If a CAN component goes bad you can’t “Solder” at competition. No soldering, welding or anything else that produces smoke per rules. Afaik you aren’t allowed to just go out to the parking lot either. I’m speaking from experience on the last one. We got a very stern talking to in 2013 when we couldn’t solder at the event per rules so we had to twist, tape heat shrink and pray for our limit switch connections. Having the wagos or Weidmullers for in a pinch is highly recommend by me anyways. Some backup plan.
Otherwise soldering is great! Especially because with quick connections people can undo them thinking “oh I’ll put them all back later” and they get the order of the daisy chain wrong. You can’t change the order of soldered components quickly. Can be a blessing and a curse.
It does if you disconnect a set or accidentally leave one out of the loop when redoing your connectors later. It happened to us when the rest of the wiring is a mess. The students in a rush thought everything was back connected properly but they had left one MC out, one end was connected but the other end was loose from its connector after all of the rearranging. They couldn’t tell by looking, only once they got to the field and 3 out of 4 wheels were moving they realized one must’ve been misconnected. Soldering would’ve prevented that. And the order matters if they have the PDP midway through or at the end with the terminating resistor jumper.
We should’ve but the issue wasn’t about the soldering iron. It was about the smoke it produced. It was electric, but they were worried we would set off the smoke alarms in the gymnasium. The reason we weren’t allowed to do it outside I was told is you can’t work on the robot outside of the approved pit areas, field or practice field. I’ll find that rule, hold on.
E108. *Work in designated areas only. At the event venue, teams may only produce FABRICATED ITEMS as follows: A. in their pit area, B. in another team’s pit area with permission from that team, C. while queued for a MATCH or Practice FIELD (given space constraints, extra scrutiny regarding safety is required), D. any area designated by Event Staff (e.g. Playoff Pit Area, etc.), or E. as permitted at provided machine shops that are available to all teams.
That’s from the Event rules manual, not the game manual.
Crimp connectors get a lot more love in FRC but we’ve also had good success with XT30 on CAN wires. The main trick is to assemble the full connector before you solder so nothing shifts on you. Some of them also come with the boot on the back so you don’t even have to mess with heat shrink, which is nice.