Okay hey guys, so I have this question.
Is it legal to have a quick release after the motor controller, but before a motor so that you could separate/sever the electrical connection quickly. The same quick release used to connect the circuit breaker and the PD Board to the battery.
Many teams use Anderson connectors for this all time. 45/30 amp powerpoles work well and are much smaller and designed for 10/12 awg wire unlike most connectors for the large anderson connectors that we use on the batteries.
According to current rules, yes you can, but there could be a reason as to why they may change this in the future…
R49
Branch circuits may include intermediate elements such as COTS connectors, splices, COTS flexible/rolling/sliding contacts, and COTS slip rings, as long as the entire electrical pathway is via appropriately gauged/rated elements.
My team did have quick disconnects this year. The only problem we had was that sometimes they would wiggle themselves out just enough to not work. It wasn’t a huge deal but it was just an extra thing to think about before every match.
Some type of connector is recommended to allow fast replacement of damaged or defective sub-assemblies. As pointed out the Anderson 30 and 45 amp connectors are one of the best ways to do this. However, a simple design where the speed controller is mounted near the motor works well. Quick connects on the controller itself, allow shorter motor wiring and less opportunity for failures. We use 1/4" spade connectors on the controllers and Andersons if we can’t position the controller and motor close to each other.
CHS Robotics used (pretty sure we still are) the Molex .093" series wire to wire connectors for interconnects between the PDB and the Motor Controller, and the Motor Controller and the Motor. These were only for the lower amperage circuits (20 amp max on a connect specc’d for 15 amps). We used a set of Anderson PowerPoles with a 30 amp rating for the 40 amp circuits (but we had some problems with failure of the solder joints. Possibly consider getting the actual crimper for the 45 amp contacts, or switching to a different connector, possibly a Molex).
At university, we use the XT90/60 and Deans T-connectors for high amperage circuits (75+ amps). The nice thing about these connectors is that they are actually fairly small, do not tend to come out easily, and very robust. Bad thing is they can’t be panel mounted. Also, the Deans connectors are not the safest of connectors (unshrouded male pins).
One thing you should do is design your system to be modular and, well, idiot-proof. If you package your entire control system (cRIO, breakouts/headers, and PDB) and place modular interconnects between everything (use wire-to-wire connects for power, and 0.1" headers to DB9/15/25), you have made a system very open to prototyping (just plug and play, quite literally), and setting up your system for competition is fairly simple. If you standardize your connectors to the type of circuit, i.e. a particular connector for 20A circuits, a particular connector for 10A circuits, a particular connector for 40A circuits, and a particular connector for 5V circuits (this one is key!!!), and you do this between the controller and power, then essentially an idiot (i.e. a rookie) could wire up your robot for you.
We always use Anderson Power Poles in the wire that connects a motor controller to a motor. They are reliable and fairly easy to crimp. This season, we also got the clipsto go along with them, and they worked like a charm. In the past we have used zip ties too, however.
You should double check what you’re using… All connectors must be “appropriately gauged/rated”, per R49, previously quoted. To me, that says that if you have a 20A breaker on a given line, any connectors in line with that breaker also need to be rated for a minimum of 20A. For 30A breakers, they should be rated for 30A or above, and for 40A breakers for 40A or above. With what you’ve suggested above, you are using connectors that are rated less than the breakers - as I read it, that violates the rules.
The crimper for the PowerPoles works really well, and i highly recommend it, although its not necessarily required. For the open PP connectors (shaped like a U), you can bend the tabs over carefully with a pair of pliers. Even with the crimper, though, I recommend everyone solder the terminals as well. So long as it is properly soldered, it’ll never be coming apart. The key is to solder it properly… with people new to soldering, its very easy to get a cold solder joint and thus a weak connection that’ll break off easily.
Thanks once again! Okay so I’ve talked to my team’s electronics guy and he’ll be checking over this. Once again GOOD LUCK TO ALL TEAMS AND THANKS FOR THE HELP
Ham radio operator and a boater here: I’ve been using Power Poles for years and I love them. Spend the money and buy the crimp tool. The crimp puts even mechanical pressure on the wire, and creates wire/crimp areas that are pressure tight. Even mechanical pressure means the crimp will not come off in abnormal use. Pressure tight means no corrosion at that point (Corrosion is bad on a boat).
They come in colors and the right sizes for the job. They give you the ability to do both “correct wire colors” and allow for final decision at the device. Case in point, swerve drives have two motors close to each other. The wires coming to them are black/red indicating power. But the Power poles are Black and Red and Black and Yellow, and they mate to the same colors on the motors. (Drive and steer)
On the boat I have lots of pairs of items. Port side gets black/red starboard side gets black / orange.
There are many crimpers out there, but we use the one from West Mountain Radio. Same guys that make the battery analyzer, CBAIII. The crimper is a military style ratchet crimper and does three sizes of terminals.
Does anyone have a part number for the crimping die used for the powerpoles? I’m having a hard time finding them.
We don’t currently use these connectors, but I was interested to see how much it would cost to get into the game.
There’s a number of complete ratcheting crimpers online for ~$40, but we already have a number of ratcheting crimpers that the dies can be swapped out of. Doesn’t make sense to buy another full tool when all I really need is the die…
but I’m going to doubt it will work with your tool.
OTOH, buy the new one. Figure 40 crimps a year, year 1 its a dollar a crimp. By year 5 you are under 25 cents a crimp. Loan it to the three teams in your area to use and soon you are at a penny per crimp.
I believe our crimper is made by Xcelite, not sure on the exact model, but something like this.
I have purchased Paladin dies for it in the past (like this one)
The dies you linked look like they would fit our crimper, and I saw them when I was searching, but do any of the ones listed work for the powerpole connectors? My impression was that this die set would allow you to crimp other style connectors with the TRIcrimp powerpole tool, but does not include the die that comes with the powerpole tool.
Plus I was looking for a single die, at $55 I might as well just buy the crimper I linked previously (which appears to be the tool that this set of dies is meant for).
We use the Anderson Powerpole connectors. If you do them right, they shouldn’t come apart. However, we wrap tape around ours just to be safe.
If you were to put motor controllers that far out, wouldn’t you have to make your PWM cables really long, too? We try to keep all of our wires short to minimize resistance/emf interference.