Hi, I’m quite new to VESC and I’ve cumulated some questions. If anyone knows the answer or has some tips & tricks it would be greatly appreciated! I’m using a MakerX DV6s with Radium 6455 175kv motors with 18t motor, 66t wheel pulleys on a 150mm pneumatic wheel, and I weigh about 90kg/200lbs with my bag.
Is it normal for the motor to overheat super quick? Or is it just the rather poor choice of using small motors with big pneummies and heavy rider?
I noticed that when going at near max speed and hard braking, there’s hardly any braking at first then around the middle rpm it brakes hard.
I noticed a similar thing with the throttle where it starts off pretty slow(could be due to small motor & heavy rider big wheel). Then in the middle it accelerates and slopes off near the top of the RPM limit.
Sometimes when I try to configure settings through the bluetooth module it reads & writes fine to the esc connected directly to the vesc, but refuses and cuts the connection to the one connected via CANbus. What could be the reason for this?
Aside from this, any tips & tricks would be much appreciated! Perhaps this topic could be a grouped info for new VESC users or new esk8 riders who wants to know the technical deets for their DIY. Thanks in advance!
No, please define what overheat is. I’d say that anything under 80 Celsius is fine, closer to 100 might aslo be ok, depends alot on the motor.
Furthermore, what are you pushing the motors to do? You have pretty decent gear ratio so guessing you’re running a decent amount of current to accomplish any sort of temperature problems?
Tinker with regen current limits and ramping in the vesc tool until you have a breaking profile you like. This is abit like religion to what you’d prefer I’m afraid.
Same thing here, tinker with the ramping. I don’t see why you shouldn’t be able to do a burnout with that setup given theres not obvious bottleneck in power on your board.
CANbus is known to be abit buggy when it comes to updating, I sudgest connecting to each ESC individually (selec device when connecting with BT) and writing settings respecitvly if double write over CAN doesn’t seem to do the work.
theres probably a bunch of topics on this already, search the forum abit or join the VESC discord if you want to chat with someone
This isn’t a vesc tweaking solution, but have you tried different gearing? Somewhere closer to 4:1 I think would help. For everything else can you tell us what your motor current and battery current regen is set at?
I’m running 60 motor amps and 40 battery amps through the motors. -60a regen aswell. I thought my gear ratio was a bit strange, but guess not! Now I think it just has to do with my geography. I mainly use it to commute and Korea has a lot of hilly areas. Especially my university where it was basically built into a mountain so that doesn’t help for sure.
Here’s the road ‘profile’
I have to take a break at around the 1.5km mark as my motor reaches the 100c limit and I can’t go any further. I reckon if I have some flatter areas it’ll be all fine as long as I’m cruising. I could try to get a log and map out the current data too!
Noted! I’ll have a look see with the settings. I was concerned as it basically didn’t give me any braking until I slowed down to a medium speed.
Not gonna lie, even with the tons of reading & watching I’ve done with VESC, I still don’t know shit hahahaha
Oh yup. Seems strange as I can see the other esc show up on vesc tool. I select it, and it just shits itself. Sometimes it’ll say something like unable to read firmware version or something like that. I’ve flashed it with the firmware from MakerX. Perhaps it’s not the best firmware for it?
Yeah I was initially going for the highest gear ratio I can to help the motors but I chose 18t as it’ll help reduce belt slip. I’ll be getting a Boardnamics XL mount with the idler so I should be able to try out smaller motor pulleys soon!
I have motors at 60a, -60a and battery at 40a, -12a.
Thanks for the replies! I’ll have a more deeper look into some vesc settings!
I think my vesc’s settings or firmware’s cooked or something. I noticed a few differences to normal when I did a firmware update. I’ll look into it more for sure.
Firmware update erases all settings, you have to start from the beginning. Motor detection and everything. In general, never do a firmware update solely because the VESC Tool suggests it. If you have a reason to, great, do it. But VESC Tool suggesting it is not a reason.
Yeah it’s a habit where first thing I do when I receive a device is update it’s firmware. I should’ve read the config or settings before I updated. Granted, motor detection is something to do when connecting motors but yeah. I saw firmware update available(more of vesc telling me to update) and hit update. I may fall back to firmware 5.03
This is likely why your high speed breaking is weak. Very simplified think of motor current settings as your low speed and your battery settings as your high speed. This doesn’t hit all the details but regen at -12a is low for high speed breaking in my experience. I have my battery regen set to -40 to get stronger breaking at speed. It will be much more reactive at speed so test it safely and make small adjustments until you find your sweet spot. I also have a little negative throttle curve to soften the inputs and keep it from feeling too twitchy
Where I live hills are a way of life, everyone has calfs and quads for days lol. when you put your board specs into the calculator try to (my opinion) shoot for 10-25% more top speed than you generally cruise at. Motors are more efficient (less heat per output) when run around 85% duty cycle so this is my soft target when choosing my gear ratio and motor kv.
If you’re near that point for your hill climb you may need to move to a larger motor can size - more motor less heat. On seattle hills i use 150kv 6485 reachers and never have heat issues, on my brothers flipsky 175kv 6355s he was overheating and burning them up after a while. Anecdotal experience and we ride very different. Some of the pnwesk8 guys run smaller than 63/6485 motors… but im not seeing many smaller cans on the group rides
Thank you! I selected -12a as that’s the max charge rate (per vesc) for the 40Ts. You reckon it should be fine to bump it up to like -24a or so? I guess it should be fine as it’s for short periods.
Ahh alright. Yeah I did select a pretty low kv + high gearing compared to what I had before. But perhaps it wasn’t enough?
Yep I’m also noticing that too. I reckon I might want to go bigger cans soon.
I would bump it up, when i need breaks i need them so i stop caring about a little battery aging. Also on all my logs it shows when i hit high regen it is very brief and drops fast to a more reasonable regen current. It’s pretty hard to pull -30a regen and still stay fast even on big hills
The 40t spec sheet says 6a rated charge so though it’s not nice, they should be able to handle -24a without issue. I personally wouldn’t be concerned about a little more than that in this use case
Yeah I’ve got it set so -12a per motor at -24a total. Maybe it’s just losing sync or something? I may bump it up to -15a per motor at -30a or so total. Even then it was quite scary as I expected some level of braking yet there just wasn’t much that came. And I don’t rly care about the battery pack lasting as I’ll be building a new one with P42As where I can do -32a regen total.
That rating is for continuous charging so you can likely do even more without issue, just keep an eye on long fast declines where you are on the break hard for minutes at a time - which I don’t ever encounter. And don’t charge at that rate
Im at near double my max charge rate and can quickly go from 35mph to 0 in a few seconds for emergency breaking on down hill sections. This is the only time i ever see close to my setting and it’s never for long. Also at a certain point the battery amps go down as the motor amps become the dominant variable.
My opinion and advice is to set the regen as high as you can actually brace for and use in an emergency without breaking traction. Id rather be stopped on abused battery than have an amazing battery lifespan folded over the hood of a car. I do have to ride very definitely around here so my priorities may not align one of the good things about vesc is you can make these choices.
For good or for ill. I don’t think you could set it and also use it too high - traction being the limiting factor. Maybe some edge case could become a serious hazard to the board or start a thermal runaway: like breaking while being towed by a car or something. Doing things like that for tictoc or something are fucking around, the find outs usually follow closely behind .
Ahh yeah makes sense. I’ll try -15a per motor and see how I like it. I don’t doubt the 40Ts can handle it. Plus, when I feel like building the pack with p42as those can handle abuse even more. Vesc does seem to work in an interesting manner.
Same here. It would be a personal nightmare to even scratch a car with my board as it’ll be a whole law thing, calling insurance, etc and possible fines. I’d rather have my board on fire but stopped in time than have to hit someone else. I’ll do some experimenting for sure! Hopefully I can find some 125mm airless rubbers soon as I’m not a big fan of thane. I like the comfort these 150 pneummies bring but due to the profile it doesn’t grip as well as I’d like and it also causes too many fitment issues. Hopefully that deck I’ll be getting from you(Thanks again!) will help with some of the issues.
Update -
I’ve rolled back the firmware to 5.03 and it seems to work a lot better now. Ofc I get that warning of older firmware which is annoying, but settings seem pretty correct.
I’ve also increased battery regen to -15 and it seems to brake pretty good. I’ll do more testing for sure
The VESC tool also seems to not get that weird issue where I can’t read from the other vesc.
For motor temps, I tried it on a more level area and I think I just need bigger cans. I had a relatively short ride but the max temp I saw was 75c. Just the fact that the board has to pretty much climb a mountain + hillsto get to where I need to be.
I’ll continue to mess with throttle & brake curves and currents. Maybe even mess with FOC tuning. Thanks for the tips everyone!
Don’t be scared to bump your regen amps like WAY higher.
The reality is that the battery will never see that full value for anything more than a fraction of a second and as has been mentioned here several times already, brakes are more important than battery life anyway.
Unless you’re getting towed around everywhere by a car while holding your brakes on the esk8, set those brakes as high as what you need them to feel safe braking.
when you put your board specs into the calculator try to (my opinion) shoot for 10-25% more top speed than you generally cruise at. Motors are more efficient (less heat per output) when run around 85% duty cycle so this is my soft target when choosing my gear ratio and motor kv.
one of the good things about vesc is you can make these choices.