We’re thinking about switching our four lift motors which are currently powered in four motor ports to be run off of two Y-Cables, using two of the same motor ports. We’ve been using Y-Cables on the base all year and haven’t noticed any problems, but I wanted to make sure there wasn’t something I was missing.
So, does anyone have a reason that what I’m suggesting would or could cause a drop/change in performance? Or will there be no noticeable difference other than less cable being run?
I thought y cables split the power to each motor, decreasing the overall strength.
Crap, really?..My lift is running off y-cables…
Our lift for one of our robots is running off of Y-Cables as is our intake system. We haven’t noticed a large difference.
No, using Y cables does NOT reduce the power each motor receives.
From my understanding, each port can draw as much current as it likes so long as the combined current for that breaker on the cortex/power expander is less than it’s limit (EDIT: obviously motors have their own in built protection too, but that has nothing to do with Y cables). I.E. Port 2 has a motor, port 3 has two motors y cabled together. Port 3 would just potentially draw twice as much current as port 2.
I may be wrong with my understanding, but I know for a fact that Y cables do not split the power to each motor. I personally use Y cables on every robot I build, as I just see it safer to use ports 2-9 with Y cables and an extra 2 motor controllers than using ports 1 and 10. As we know, ports 1 and 10 are different from ports 2-9, so I prefer to use identical “types” of ports across all my motors, and I’ve heard of some horror stories with ports 1 and 10 
I don’t have any issue with Y cables, so I just stick to what I see as the safer side.
EDIT 2: You may find this thread useful: https://vexforum.com/t/y-splitters-cables/16981/1, in particular, the answer to Question 1. in post 2, and posts 3+4.
~George
Our intake is wired off a Y-cable, no difference in performance. The battery is probably what would cause a change in performance.
Excellent. Just wanted to make sure I wasn’t missing something. I’ll throw the Y-Cables on Monday.
Thanks for the help.
Just to be safe, we have never used Y Cables on our robots just because of the thickness of the wiring. The way we figure it, you “theoretically” have less current capacity when you’re using one port instead of two. It probably really doesn’t matter much at all, but it’s just something we don’t like to do.
So what I’m reading is that there is a power drop, but because there’s so much in supply already(4 amps), the performance does not drop because it still runs at full capacity (1 amp).
Cool 