Field Oriented Control.
thanks! was wondering what it was
There’s a more technical way to explain it but FOC with the hub motors provides smooth acceleration/deceleration/coasting and is eerily quiet. Someone much smarter than me can explain it better but that’s typically what I like to use it for, especially commuting in the city when I want to remain stealthy.
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It definitely feels like the throttle and brake are more authoritative than when in bldc mode. I personally thought I would miss the sound of the motors but It opened up a whole new world with FOC. The sound the urethane makes when it struggles for traction under acceleration is intoxicating.
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I agree, I wasn’t sure if it was a psychological thing - like I feel I’m more in control of the board because it’s so quiet, as if natural skate instincts kick in as opposed to hearing motors which activates my “driving” instincts. I really haven’t had the desire to switch back to BLDC yet, even riding in large areas when I can gun it. That intoxicating feeling happened to me once, riding through a pitch black bike trail at midnight with my buddy. Just LED’s on the boards and FOC mode so we can hear the natural sound of the forest and wind rushing past us. It felt like a video game and gave me more euphoria than sitting in one place and flying FPV drones. It’s like we were skate Ninjas.
What are the main differences between BLDC and FOC?
To me, BLDC is louder, aggressive and has higher top speed. FOC is quieter, smoother but lower top speed.
I am not a technical expert as well but if you check FOC and BLDC motor phase diagram they are easier to explain.
FOC is vector control and so the wave is sinosuidal (sine wave control). Instead of ON OFF ON OFF ON OFF (BLDC mode), it has a nice sine wave / trapezoidal wave current output to each phase. Instead of 0 then 100 then 0, its like 0 10 20 30 40 50 60 70 80 90 100(peak) 90 80 70 60 50 40 … and so on. Since the rise and fall of current are gradual, it produces less high pitch / noticeable sound.
At least this is my perception and the simplest logical thing I could understand.
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@laurnts that sorta makes sense. I don’t understand why the top speed isn’t the same though. Is it possible to switch to BLDC once you’ve hit FOC top speed?
No thats not possible I suppose. The way it works and the calculations are different. I don’t think its smart to do that as one little glitch or wrong motor phase powering would send you to the ground at the speed you hardly control.
Quick update to this build. I swapped out the Jet Spud for this blank 36" double kicktail deck from Ehlers Longboards. I immediately sanded it and painted it gloss black with some coats of polyurethane. The wheelbase was too short so I had to drill some additional truck holes and slightly modify the enclosure. I also added a tail guard/foot step. Although it’s not really a mini cruiser anymore, I can easily swap the deck between this and the Spud depending on the situation.
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It’s a spud exodus! Why the switch? Just wanted some kicks?
Nah still love the Spud! It was more out of curiousity about the double kick. I almost returned it because the wheelbase wasn’t enough but happy I made it work. I’ll let u know how it rides. What deck are u looking at next?
That deck looks good in all black. What wheelbase are you at now after modding it? If I’m looking at the right deck, don’t both decks have the about the same wheelbase at around 21"? I’ve had my eye on the Lonely Pirate for a while. Looks like it’s got an adjustable 23-27"wheelbase. Wish it came in a cheaper blank version since the cool graphics are gonna get covered anyway.
http://www.skateshred.com/index.php/whole-longboard-decks/the-lonely-pirate-37-x-10-deck.html
Thats what I thought but when it arrived the wheelbase was about 18" so I had to drill the extra holes. Kind of misleading on the website.
Yeah, that’s a big difference. I tried electrifying my ~25 year old Santa Cruz, and extended the wheelbase from 15" to 18" and it definitely feels too short. For science, I’m thinking of taking my old 30" street board and mounting the trucks on both kicktails for a super maneuverable, ghetto drop deck setup. Can’t wait to see some videos of the new ride…
I’ve ordered a Loaded Poke for this next one. My only question now is if I’m going to recycle the motor from my old one of spring for a hub. I’m thinking of starting with the current one and maybe going hub later on
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@Mobutusan Damn that sounds insane haha can’t wait to see some pics!
@siggs3000 Loaded Poke is awesome, I love the contour. Have you ever tried the Landyachtz Dinghy? It’s tiny but it’s something I may look into electrifying in the future. Kind of reminds me of the Poke.
@RunPlayBack - I actually looked at the Dinghy but I was looking for something just a little longer than the spud so my front foot would be behind the front truck (instead of right on top of it) and also something that had a little bit of flex. I’m looking for a smoother ride and slightly less scary than having my foot so close to the nose. Though insanely expensive, I think the Poke is going to deliver! I’ll make a new build thread about it soon.
Your other build is so sweet, by the way. Clean and cool!
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