@Flasher Did you mean me?
It’s dangerous because you’re adding an automated failsafe behavior that could brake you at an inopportune time. Imagine if you had a car behind you and your remote cut out. It would be better to coast than to brake.
This is why I say it’s dangerous. Set it too high and instead of coasting out. Even going from acceleration to no power can feel like quite a jerk under certain circumstances, so active brakes can make that even more extreme.
It’s just something that if you have enabled, you need to test it thoroughly and be very aware that you’ve changed the expected behavior of the system.
Nope. In rocket. Redundancy is studied and implemented correctly. Not let’s plug in two engines.
3 Likes
This is not at all what I’m saying.
Please stop trying to speak for me as you seem to be struggling enough to do it for yourself.
2 Likes
I am saying adding an additional point of partial failure is acceptable to me if it removes a point of total failure.
1 Like
Redundancy
6 Likes
ask your questions here!The one time I decide to take a nap and this is what I miss. Jesus
6 Likes
oh boy! that’s a mighty long thread. *self portrait
9 Likes
Just a fourth engineer popping in here, agreeing with the other three engineers regarding actual redundancy.
Two spacial seperated recievers could add a small amount of safety. But there’s also the question of the two reciever potentially interfering with each other depending if they are ACK-ing anything back to the remote. It would be an interesting implementation to do dual redundant reciever correctly, a bit tricky with ppm but a uart remote should be able to easily notify the controller when signal dropped. If you leveraged two different bands say 2.4 and 5 GHz it could be even more robust.
There’s also an important question that is board dependent, I think on a Carver with wide wheelbase a single reciever failure produces a potentially more dangerous situation than brakes cutting, could veer the board and throw you. Wheras maybe a more traditional skate single motor might be much less dangerous so it just depends.
The only reciever problems I’ve ever had are due to shitty wiring by your truly, always remember to strain relieve your wiring.
I also feel like growing up my whole life skating I’m not that scared of my brakes going out? You can just foot slide, but again depends on board type and speeds involved I suppose. Torque cutting instantaneously is much scarier though, I’m not convinced an unbalanced one side torque cut would actually be better or throw me into speed wobbles.
21 Likes
Correct.
I will say it again, the only two ways of adding redundancy into this system is spacial and frequency diversity.
That means either two receivers separated by as much physical space as possible or two receivers operating on two frequencies as far apart as possible.
This is the point that Shartis and Brian miss, if you cant achieve at least one (but preferably both) of these you do not have a redundant system.
6 Likes
2 Likes
Actually I am pretty sure I am the only person participating in the conversation with a properly implemented redundant dual receiver on their actual board. 
2 Likes
I can only speak from experience, but my first Carver build had individual, integrated antisparks for each FSESC6.6, because I was lazy and lack conviction I didn’t combine them. And also wanted to ride.
It was fine until one of my switches failed and half of my high-torque Carver lost power and tossed me onto the asphalt. So yeah, this is a real danger with bigger boards, and board construction factors in here. I can’t imagine if you had both receivers cutting out intermittently and the throttle between each side fell out of sync.
Don’t worry I put some tape on that switch and rode it for another month until I rebuilt it, like a proper idiot.
(Don’t try this at home)
It’s okay @Lee_Wright, we all just found out that my mom raped @professor_shartsis…it explains a lot.
3 Likes
Me too actually. But she sends Christmas cards now so I guess it’s okay
3 Likes
she did? i don’t think so i’ve never met your mom.
Not face to face
1 Like
Which error was being reported?
If you received a low voltage input error from the battery, that could easily cause both vesc to error.
More info please! Also we should move this discussion back to the parent thread, potentially.
I’ll give you something to reach for.