What if there was a way to travel back in time, but due to the possibility of creating a paradox and dissolving reality as we know it, you could only afford the ability to stop ONE USER from ever finding out about/joining the esk8 community. Decisions, decisions.
Unnnnnnfffff
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I hate to point out the obvious, but that’s a TI.
I ask for pics of Eva Longoria, and you post Reese Witherspoon. I’m not saying she’s not hot, but just not what I was looking for.
Gotta work with what ya got sometimes
I forgot to mention:
Results:
Efficiency Control: 32.07 miles per kilowatt hour
Current Control: 21.63 miles per kilowatt hour
Suppose I’m an electric skateboard vendor, and a previous customer asks me what options they have to achieve greatest possible range and efficiency on their electric skateboard when commuting in start and stop city traffic. The customer’s route to work features many stop signs and stop lights, so they start and stop very frequently, but they live in a completely flat area and don’t expect to encounter any hills. The board we are discussing has a battery which typically runs at 45.98V, (4) 81.42kv hub motors which are 0.136ohms and has 83mm diameter tires. The customer states their only requirements are they want to ensure the board is capable of 30mph top speed on flat ground, and aside from that requirement, they also want highest possible range and electrical to mechanical conversion efficiency while repeatedly accelerating at full throttle during their start-and-stop morning commute. Should I recommend “efficiency control” or the “classical algorithm” to achieve this customer’s requirements (at least 30mph top speed on flat ground and greatest possible range & conversion efficiency while repeatedly accelerating at full throttle in start and stop city commuter traffic)?
Stop Sign Separation Distance: 183.5 Meters
Full Throttle Acceleration Distance: 150 Meters
The 30mph-capable rider with “efficiency control” gets 148.25% as much range in start and stop traffic with stop signs placed 183.5 meters apart compared to the 30mph-capable “current control” rider, while both use full throttle acceleration for the first 150 meters of each acceleration cycle, followed by mechanical braking.
Efficiency Control: 51.62 kilometers = 32.07 miles per kilowatt hour
Classical Algorithm: 34.81 kilometers = 21.63 miles per kilowatt hour
The cheap china hub motor breaks?
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How about an esk8 enclosure with an integrated heatsink that has fins that stick out a bit? One would couple the controller to the heatsink from the inside. Enclosure is still sealed and weatherproof. (maybe this had been done already idk)
Eboosted dose that with his enclosure.
I did a ghetto one.
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So another weird thought. Would having a long threaded motor shaft that acted as shoulder bolts on a precision truck work? Btw, It’s nice having a place where smart people answer all my stupid questions. 
Could work (basic direct drive) but you’d need to thread one of the motor shafts backwards to keep it from wanting to undo itself on torquey starts. Are you assuming the motor pulley would screw on too?
Source: https://www.vesc-project.com/node/628
"I may be a little bit late to the game but this is of great interest to me.
I represent an undergraduate team (duke-ev.org) who builds ultra-efficient vehicles and we’ve been considering picking apart the vesc firmware to borrow some useful algorithms. I had made some edits to the firmware for a different project and I’ve gotten familiar enough with the firmware that I could probably get this implemented without too much difficulty. Benjamin has made it such a breeze to edit and flash firmware; I am very grateful.
Aside from the wildly unrealistic operating conditions our vehicle competes in, I do completely understand the appeal of this technique partly because I think about efficiency pretty much every waking moment. I think the big selling point is what you said earlier about how someone riding at partial throttle could theoretically match the acceleration proposed by your algorithm, but a human guessing what acceleration curve will make the optimal efficiency is never going to be as good as an algorithms forming a closed loop control to hit exactly the optimal efficiency. When we run our vehicle for record attempts, for example, we have 2-3 buttons which just apply the exact acceleration curves for optimal efficiency rather than using a thumb throttle.
I don’t want to make it sound like our ridiculous use case is the only reason you would use devin’s control, though. It’s definitely extremely valuable to just make the board run efficiently on its own without the user needing to tweak their thumb at just the right amount. Maybe you could make the argument that you’re splitting hairs on efficiency, but I could also make the argument that if you sell 1000 boards and each one runs 10 miles a day and saves 1% efficiency, over the course of a year that amounts to a lot of CO2 and $$$!
I’ll do some more research and further consider implementing this into the firmware. In the mean time, devin I may DM you for more theoretical details and I hope more people can see the value that this offers.
Gerry Chen"
^I hope if he doesn’t implement it someone else will… the easiest way to think of it is having a different motor current limit at each rpm, for constant efficiency during full throttle acceleration. When you “turn down” the efficiency setting you get more power and greater acceleration, and when you “turn up” the efficiency setting, you automatically get more range in start and stop riding, sacrificing some acceleration but not top speed, because more motor current becomes available the faster the motor turns. While accelerating through very low motor rpms, low efficiency is basically inevitable…
so is this basically what i suggested
before?
It’s similar in that available watts would be based on your present speed with more watts available at higher speeds. Rather than a targeted watt hour per mile it is a targeted % of electrical watts converted to mechanical watts and the % value is chosen through a setting by the user… A lower efficiency setting gives more acceleration while a higher efficiency setting gives more range but less acceleration.
Technically though, even standard current control mode gives you increasing watts with increasing speed, because it takes more battery amps to maintain the same # of motor amps as the motor turns faster. The difference with efficiency control is the user gets to choose an efficiency setting value, and when they accelerate at full throttle the controller will allocate the exact # of watts that achieves that targeted % efficiency during acceleration.
Has anyone ever tried to use the pos and negative from the top of an 18650 cell to do something? Anything?
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What about using a regular dual motor board that works as normal, but the front wheels have 2 small motors on them functioning as brakes only.
You could use a ppm splitter or a second receiver and the cheapest vesc you can find. It would be nice to have additional braking force and not skid on sandy concrete. The whole thing could be done with the price list below
3d printed motor mount clamp $0
Motor mount plate scrap aluminum/steel $1
Belts $8
Motors x2 $40-$60
Dual vescs $120 from aliexpress
Misc hardware $10
Total of about $200 for 4wd braking abilities and massive performance and safety increase
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