Hi,
What do people think of using http://www.o-digital.com/uploads/2179/2187-4/Screw_Wire_Connectors_P1~_P6_699.jpg type of things on FRC robots? I just tried connecting a couple wires I had lying around (I think 12 or 14 gauge) with one and it was pretty secure, not to mention quick and easy. Has anyone used this on a robot and have anything good or bad to say about them?
Not a chance. Those are generally for solid wire, in installations that don’t move around.
At inspection, I’d need to confirm that it was a well-engineered system to accept those as safe per [R08].
Aside: This was posted in the CAN subforum; I think you mean for this to be in the main Electrical forum. (There’s no chance you want to use 12 AWG wire on the CAN bus with wire nuts, right?)
Alright good to know, I won’t be using those on anything but solid stationary wire (maybe the OI, maybe).
Oops, that is the danger of having two CD tabs open. I don’t suppose there is a way to move this without PMing a mod?
I fully agree. They work great in houses but not on machinery (or robots)because the vibrations make them unscrew.
If you want a secure way to use that terminals it would be more complicated then twisting and soldering. For the most secure yet primitive Pete way of using it is.
grind of the plastic not surrounding the metal which in most terminals that makes the rest fall off.
Put the wires in and do a quick crimp to hold the wires in place.
solder strengthen so it doesn’t need to be screwed. (Which is where it becomes more useful to just solder.
Wire nuts may not be your favorite connector, but. They are available products UL listed for both stranded & solid wire. I have seen them used routinely on equipment that vibrates a lot more than a FRC robot ever will. You can tape them after they are made up if you are paranoid. The connection properly done will at last the life of the robot.
As in all things you need to use the right size for the number & size of wire.
Oliver,
Moved the thread.
These types of terminations are commonly know as ‘wire nuts’. Some have a spring inside and some have no metal inside. Like the WAGO terminals, there is a specific strip specification when using these connectors. If you strip too much, conductors are not insulated. If you strip too little, the wire nut falls off. While I have seen these used on robots, they are legal but not appropriate in many cases. I suggest that teams make as few splices as possible especially in high current conductors. Each splice a person introduces, also adds one more point of failure and higher resistance in the path. As noted most are designed to terminate both stranded and solid conductors. However, they are generally not recommended to mix conductors in the same termination. I would certainly question any splice on #6 wire using these connectors.
Does anybody use solid wire on a robot? :), By the time I get to #6 wire I am generally using lugs & not twist connectors. The Ideal twist connectors (wire nuts) are UL listed for solid and/or stranded wire. In building wiring it is probably the easiest way to make the transition.
I agree with Al that you want as few as splices as possible. Every one is a failure point. Whatever ever method you choose make sure it is done properly.
They’re nice to use when tossing together prototypes or when you’re trying out a quick fix that you’re not sure will work, since they’re so easy to assemble/install/remove.
Wire nuts can hold, but I personally just don’t like using them given the abuse that robots take.
Oh yes… we do. In fact, this was the first year we didn’t.
It’s the result of having a sponsor (Ford) who donates some wire to us every year… but it’s primarily electrical panel wiring for Industrial panels. It’s a pain to work with, but when you’re living on a budget you learn not to complain 
We have used wire nuts definitely for temporary connections to sensors for testing and prototypes.
I have used these Wago compact connectors on machinary when a splice was needed for components with flying leads. Turns out I do not know how ti insert a picture but here is a link to the picture:
And here is the catalog page:
http://www.wagocatalog.com/okv3/index.asp?cid=51&lid=5&str_from_home=first
After the 2011 North Star regional, we threw some into our standard kit of parts, although they’re only used in emergency situations. At North Star that year, we started burning out FP motors during elims, after only one or two matches. We didn’t have the time to figure out or fix the mechanical reasons for this at the competition, so we just started swapping in new motors to keep the beast running. Needless to say, at that point having some wire nuts handy would have made swapping new motors in a lot quicker and easier! We managed to get the connections soldered each time, but it was always a serious time crunch to get the swap done in time. As Al said, you want as few splices as possible… but situations like this are ideal for making a quick splice instead of running the wire through the entire robot.
We used them on parts of the robot that were swapped out with our main and competition bots or for testing purposes.
Used properly (and every container of these - bag or box - MUST contain proper usage instructions) wire nuts are as good as just about anything. And they’re available in sizes for almost anything you’d use on a robot. For big (>10 ga) or small (<20 ga) they are not optimal.
That being said, we don’t use them, since we try to avoid splices and wire nuts are not better than a proper solder connection. For connections that need to come apart, we use connectors.
