Archived: the OG noob question thread! 😀

[Sender]

I remember 89? But it has been a minute

[ADrum707]

Just came back from a test ride… I definitely dig the new settings. Not sure what factor or what combination of factors led to it, but the motors response feels so much better, brakes are better as well. Can’t thank you all enough for your help! @MysticalDork @Flasher @mmaner @b264 @Sn4Pz @Venom121212 sorry if I forgot anyone!

[grumpypuppy108]

Hey so I’m just about ready to build a battery but i’m not sure of ALL
the parts necessary heres what I think i need please tell me if i’m wrong
50 40t cells
10 m of nickel just to be safe
charge only bms
charge port
fish paper
5 feet of 10 gauge wire
spot welder

[glyphiks]

Multimeter
Fuse for charge port
Balance wire if your BMS wires arent long enough
Heat shrink for whole battery and different wire gauges
Solder
Soldering iron
Flux
Kapton tape
Filament tape

These are a few things that I use that arent on your list!

[grumpypuppy108]

thanks exactly what i was looking for putting a 10s5p on my meepo v3 right now looking at finishing up end of december

[glyphiks]

Would also suggest that you read as much of this thread as you can

The battery builders club

Batteries are dangerous if not treated right. Nobody want to have a fire at home or lose a board due to a wrong battery design. This thread should be a summary of clean safe battery packs as well as a place where you can come and ask questions all about how best to build your own pack. Feel free to upload pictures in progress and ask our opinion about the layout, weld quality or what ever you not sure is right done or not. @moon if I remember right you had a punch of pictures from well made p…

[grumpypuppy108]

thanks great resource i have been reading just couldnt find a parts list i have a pretty good concept of cell layout

[ZachTetra]

I have a dual cheepo ESC and new model remote from dickyho…when I max out the throttle it will vary the speed (bench testing), is there any way to determine if it’s the remote throttle or the ESV itself?

I’m not excessively worried about it because it’s just gonna be used by friends who won’t pass 10mph anyway (yes I’ll make them wear a helmet), but if it’s just a new remote then I’ll pick one up from dicky when I get more goodies from him

[stan]

What’s the big difference between Uart remote connection and PPM?
Different security protocol? One is more reliable than the other?
If there is already a topic on this, please link me to it, I didn’t find anything on this subject.

[Flasher]

@stan Deckoz pointed out failsafes

Issue With Unity and Metr.at Module while Logging data

I get that. I don’t really trust UART or nonbind remotes either… See with traditional rc remotes you have 3 failsafes 1st failsafe is a hard ID bind, so when connection between remote and receiver drops or if there’s a brown out at the receiver, they are always searching for the same ID to recover link. 2nd is receiver failsafe, set buy putting the channels at the values you want to failsafe at, and removing the bind plug which records the current input, so when link is lost, it switches to…

[bollen]

PPM (or PWM) uses a single wire and sends a square wave with varying pulse width. The ESC senses the pulse width of the square wave and adjusts the motor speed accordingly.

The PPM communication uses a single data wire and the flow of information is only one way, from the controllers reciever to the ESC.
Different receivers might give out a slightly different pulsewidth when idle and that is why there is the option to adjust the deadband and the midway point of the signal.

UART uses digital serial communication (ones and zeros) and two data lines. The use of both RX and TX lines between the receiver and the ESC means that information can be sent back from the ESC to the remote. In practice this means that you can show stuff such as the current speed and power draw on the remote.

[DerelictRobot]

Unfortunately the fail-safes he’s talking about don’t even apply to uart control method, so it’s kinda like complaining your submarine doesn’t have wheels. The two systems are so different there’s no Apple to Apple comparison.

The fail-safes he’s talking about already exist in different forms with modern radios, or aren’t applicable because the tech being used isn’t RC hobby tech from the 80s.

@deckoz nerd fight me bro.

[Flasher]

@deckoz nerd fight me bro.

[DerelictRobot]

Most modern tech isn’t recording failsafe values for controls.

Sure, but in context you made generalized statements about ‘uart remotes’ that don’t even apply to the tech.

The 3 failsafes you mention only apply to analog and digital RC hobby tech. Hobby receivers have “2-3 channels” that output a pwm signal on each. A default output for each channel in case of loss of connection has zero bearing on uart method of control.

For example, on OSRR we’re using advanced industrial series 802.15.4 radios. These don’t have traditional “channels” and don’t use PWM because they can send much more complex formats of data, potentially even at lower latency, at a much higher rate than an RC hobby remote.

The radio modules alone, not even entire receiver/remote device, have their own dedicated CPU that handles it’s own fail-safes at a firmware/hardware level. This all happens automatically even below the level in which I’m programming the OSRR remote code, but is fully configurable during setup. Multiple checksums at play, 115-250k baud rate comms so it’s near real-time.

The radios are paired & encrypted, have PAN IDs they operate on and within that addresses/broadcast modes, so it never needs to search.

There are multiple redundancies, fail-safes, and safety/encryption features that RC hobby remotes simple don’t/can’t support.

[Dareno]

8’s are 89 and 3’s are 86. The site just gives you the can size not the overall.

[Flasher]

[DerelictRobot]

So your receiver should be outputting failsafe values over the serial bus aka uart when RX is lost.

It’s really a matter of systems design choice though. With uart that can just as soon be vesc or receiver side depending how it’s implemented. There’s an internal timeout on the uart throttle input that acts as a failsafe in addition to the uart comms timeout. They all do the same thing in the end.

I’ve tested this, because with VESC comms timeout set to 1000ms, I can accelerate and turn off my remote, and it will hit neutral in under 500ms.

Edit: Going back to test this further so I have better data on it. Enjoy the discussion as always Brad!

[wafflejock]

Motor detection should be done without any load or anything attached to motor but with motor on mount and wired in the same way it will be when loaded this way the BEMF measurement is accurate given the actual resistance etc. to the motor. If loaded or hooked to a wheel it will take more amps to turn but the calculated BEMF I believe would be the same.

[annihil8ted]

Yeah I guess I should clarify, mounted to the pulley with belts and wheels attached but no load.

Thanks for confirming!

I guess a followup question is for FOC, do I need to recalibrate if I switch a phase wire to reverse motor direction? My gut tells me yes but I wanted to confirm

[wafflejock]

I think yes as well any changes to phase wire length which I guess includes swapping them would change the calibration results I believe not sure how big of change that would be but can’t hurt.