We’re proud to finally release the Hurrilink Sidecar, a self contained Neo 1.1/Sparkmax adapter that shields the high voltage and encoder wires from damage or pullout. It includes the same click-lock double controller retention requiring no hardware as the Base Hurrilink, and prints completely support free.
The sidecar arrangement of motor and controller results in a 1/4" shorter package than a Falcon v3 in the motor axis! As with the base Hurrilink (top mount), no wire shortening is necessary.
Design improvements include small exposure of controller corners, making controller removal for maintenance or swap a task easier done with fingers and not requiring tools.
Note: STL file is in inch (imperial) units, as is the base Hurrilink. If imported file appears tiny, see if your slicer software has imperial or inch import settings. If it does not, scale the model 2540% in each direction. This simply converts inches to millimeters, and is a great trick to “fix” the many imperial (inch) .stl files out there. Rememeber, .stl is unitless and each dimension is numerical only so the slicer software needs units specified.
Best of luck in 2023-2024 from the 3171 Hurricanes!
Brushless motors, at least small ones are 3 phase AC input, I believe 220v. So those wires are definitely enough to shock you if you were to grab them exposed while the motors are running, or if they were contacting the frame. It’s part of the reason I designed these, I think some teams are crazy to run 3 phase AC and encoder wires all the way across the bot, but you gotta do you. I would call the exposed side, 40a 12v the “high current” side and the 3 phase side “high voltage”, but they’re just relative terms.
Edit: This is incorrect. See this:
I’ve left the input/output 10pin port exposed with clearance on the controller here, so hook up whatever you want to that! The rev thru bore allows at least 3 ways to hook up to the bot, and the CANcoders of course use CANbus, so we never really use that 10pin, but the option is there!
An aside, the 10pin is not a standardized port, so I don’t believe you can hook say a SRX mag encoder to them directly without a breakout board/conversion harness. You may know this, I just think it’s more than a little misleading.
I think I can post .STEP files next to the STLs on printables, I’ll look into it later.
If you measure the voltages coming out of the phases while the motor is running, you’ll be shocked to find that it’s much closer to battery voltage than 220v.
Hmm, haven’t measured it directly as they shouldn’t be run not connected to a motor and I’ve been very careful to make sure the students don’t leave exposed wires. I can’t find specs for the output from REV, so I’ll take your word for it. Once you get around ~48v you need to worry about jumping through skin, if you wanna specify what voltage you read.
In any case, I’ve never heard of a person being shocked by one. Safety precautions are pretty good at FIRST for being hands off any running motors or robots. Maybe I’ll hook the phases to the oscilloscope we have and really check out the sine wave this year. It’s more a design philosophy to limit the amount of wiring and keep controllers local to motors. I don’t think teams are knowingly putting students in danger.
The Neo is designed to work with 12V, which is low voltage by almost any standard. I find it very hard to believe that the Spark Max produces 220V, and if it does, I would love to hear about it.
If anything, this is backwards. FRC motor controllers are H-bridges, meaning they can only turn the voltage on or off and control its polarity. Switching that voltage on and off very fast (plus some inductance from the motor coils) produces an output voltage ranging from -Vin to +Vin, where Vin is the input voltage to the motor controller. The output voltage, whether it’s “AC”* for brushless motors or DC for brushed motors, can never be higher than the input voltage.
Electrical power is more or less conserved through the system, excluding minimal switching losses. The equation for electrical power is P = V*I. So if Vout <= Vin and Pin ~= Pout, then we must have Iout >= In. So the “40a 12v” (input) side has a higher voltage and the “3 phase” (output) side has a higher current.
All that said, basically nothing in FRC works on voltages over 12V. So while obviously not advisable, you can touch the bare wires and the most you should get is a minor shock.
* DC brushless motors don’t actually work on AC power, otherwise they would be AC motors. Instead, they use a trapezoidal commutation to switch the three phases on and off. If the motor were controlled with AC, it would be sinusoidally commutated and called a Permanent Magnet Synchronous Motor (PMSM), which is a type of AC motor
Interesting. I’ve been told by more than a few people I assumed were more knowledgeable that they at least outputted 3 phase AC, of some higher voltage, though I wasn’t sure what voltage. I take back my statements regarding the high voltage. Makes sense to me from a safety perspective too. I’ll edit my Printables descriptions later. I looked for awhile for this info you posted so, TYVM.
