Earlier quoted context omitted.
Why not rim brakes, or disc brakes for that matter? Other than lock up which you can control. And why do you need that over e brakes?
> Why not rim brakes, or disc brakes for that matter I don't know how you'd mount a rim brake on a tiny longboard wheel. Disk brakes seem feasible. I'm not a long board person, I don't know what the state of the art is here.
A guide to building a fast electric skateboard at home
91–100 of 100 posts
Re: A guide to building a fast electric skateboard at home
#9250km/h is suicide. ps: anybody here owns a gyrowheel ?
50 km/h is pretty common descending a hill on a good quality road bicycle. The major difference there is that you will have a properly balanced wheelset (a 700C wheelset alone on a decent roadbike, sans tires, are worth at least $275-350), with gyroscopic stabilizing forces. And you will have brakes . It's also possible on a road bike to aerobrake yourself on a descent by sitting more upright and adding drag.
Re: A guide to building a fast electric skateboard at home
#93Earlier quoted context omitted.
While I'm not the OP, I can provide the links to the parts I used for my electric skateboard. The ESC I used is one of those mentioned in the post. Batteries (x2): https://hobbyking.com/en_us/zippy-flightmax-8000mah-5s1p-30c... ESC: https://www.ebay.com/itm/Dual-motors-longboard-skateboard-co... Motors: https://www.ebay.com/itm/90mm-dual-6364-hub-motors-drive-kit... BMS (optional): http://www.batterysupports.com/36v-…
What wheels and trucks are you using?
Re: A guide to building a fast electric skateboard at home
#94Earlier quoted context omitted.
I can use a normal skateboard, but there’s no easy way to brake other than use your legs or “eat shit”. Not great for your knees. Electric skateboards (one I have) has regenerative braking and it’s amazing. Being able to control your speed is a pretty big feature.
what about in the case of a hardware failure
Re: A guide to building a fast electric skateboard at home
#951. learn to ride a non-powered skateboard or longboard first. I guarantee you, you do not have the balance or skills to ride a longboard at 10kph off the bat, let alone 50kph. I've snowboarded and wakeboarded for a significant chunk of my life and I'm telling you, longboarding, especially fast longboarding, is not an easy skill to master, let alone pick up as a twenty-something.
2. allsunny's comment on learning to fall is spot on. You need to know, instinctively, how to bail at different speeds. At certain speeds and obstacles you can run off, at others you have to tuck and roll, still others you will rely on your knee pads or elbow pads to protect you from impact. allsunny's comment is spot on for other reasons but for now I want to move on to...
3. protection! Always wear your protective gear! I wear wrist guards, knee guards, elbow guards, and a helmet (not full face, unfortunately), every time I ride. I don't care how good you are, if you are in your mid twenties and older, a fall on concrete is really going to mess you up. Not that it doesn't mess you up when you're a kid, just that kids have a greater potential to bounce back from these things...
OK, now on to the article itself. There's a lot left unsaid, leaving you with the false impression that you have a proper and informative guide. Unfortunately, it barely scratches the surface.
(A) Hub vs belt: hubs have more cons than just heat. Hub motors tend to get really beaten up since your motors are taking the impact of the terrain. The urethane, or "tyre" part of the hub, is also typically not easily replaceable, falls off easily, or wears badly. That's kind of changing now but for the most part if you get a cheap hub you're going to have to replace the whole thing. Furthermore, the urethane is typically very thin around hub motors and your ride quality is going to suffer as more vibrations are transmitted up.
Hubs are really quiet, though.
Belt drives have many advantages. The motors get beat up less (unless you don't have enough clearance). You can "gear up" or "gear down" a belt drive (albeit not while in motion), giving you more speed and torque options. The article makes a big deal about dust and dirt and swapping belts but most belt drives have some kind of cover and belts are cheap to replace. Most importantly, you can buy wheels from companies who actually know what they're doing in terms of urethane formulation, grip, comfort, etc. You have options with a belt drive.
They can be really noisy, though.
Remember if you get a belt drive that you need a way to maintain tension. If your kit doesn't let you do so (e.g. diyeboard kits), it's... well it's not worthless, but you'll be swapping belts out a lot.
(B) ESCs: there are ESCs, and there are ESCs. The VESC the article author mentions is indeed open source hardware and firmware, but the quality of the hardware you get is really hit and miss depending on who you buy it from - some VESC hardware cannot run in certain firmware-settable modes and will go up in flames if you try (look up FOC). Furthermore, there are so many versions of the hardware out there that it can be a nightmare to find the compatible firmware for it. And finally they're usually expensive as.
On the other hand, the cheap chineseum ESCs have their own set of problems and limitations. While cheap, they are typically not as configurable as VESCs, and sometimes lock you in component wise to the vendor's radio control system, drive and battery combo.
(C) Batteries: do not buy cheap eBay hobby batteries. I've played with these in the context of RC buggies, planes and drones, and they are really hit and miss. It is fine in the context of RC toys which you play with in a safe environment and never for more than a few minutes at a go, it's not so fine in the context of a moving EV you're standing on going at 50kph, being constantly hammered by road conditions and put out in the hot sun for half an hour to hours at a time. Unless you have taken appropriate precautions and screened the batteries and otherwise know what you're doing, I wouldn't give them a second glance.
You can look up forums for reliable battery suppliers and make your own cells or buy from those. If you want to go the DIY route, GA cells apparently do pretty well, but I wouldn't put a pack together without thinking about cell-level fusing, having either special soldering equipment or a spot welding setup, strain relief, wire gauge selection, etc. If you set it up wrong, you're going to end up with too much current running through too thin a conductor and having them glow with the heat under load. I've seen it. It's cool, but also scary... mostly scary.
(D) Oh yeah, you're gonna need a battery charger. What do you mean, you don't have an adjustable chemistry battery charger just lying around at home so you can make a choice from a variety of available battery chemistries?
Alternatively you can source a battery management system which is a circuit matched for your battery chemistry, and just plug it in to a properly set up power supply. But then you have to ensure the power draw of the drive system is set up for it.
That said, one potential advantage of having a battery management system is the ability for you to take advantage of regenerative braking capabilities of your ESC safely.
(E) Remote control. The article didn't mention this, but you're going to need one. Please don't buy a bluetooth controller, a signal hiccup at 50kph and your skin could be a smear on the floor.
Speaking of hiccups, you oughta determine, and set, the failsafe behaviour on your remote controlled EV. The typical failsafe mode is to freeroll, which means if it fails you'd better be able to ride and stop your board without having to rely on the electric crutches. Callback to allsunny's comment.
(F) Deck, wheels and trucks. So you're putting together your 50kph drive and decide to slap it on a donor deck. So easy amirite?
For heaven's sake don't do this. Longboard decks come in many shapes and sizes. Again, if you're the kind to have ridden around on non-electric skateboards or longboards, you'll have a very good idea of the available options. If not, you have to do your research. The kind of setup that is fun to ride at 10kph is decidedly deadly at 50kph (look up "speed wobble"). The wheelbase, deck shape (both lengthwise and cross-sectionally), ground clearance, softness of wheels, width of truck, stiffness of bushing, geometry of truck, etc., all make a difference. There is a fair mix of personal preference and objective necessities too.
(G) Putting it all together. It's not a PC, you can't just plug in the components and have them work. You'll want to weatherproof the components somewhat, protect them from impacts. There are also miscellaneous parts you may want or need like switches, anti-spark connectors, battery level indicators, etc.
One thing often missed in assembly, for e.g., is that people buy cool looking carbon fibre decks, crowd their receiver next to the dense batteries or high current wires, and then wonder why their low powered radio transmitter and receiver only works intermittently. Not all radios, and not all decks, but some.
In conclusion: there are a whole lot of miscellaneous matters that aren't mentioned in the post and I didn't want people reading it to think it was going to be a single-blog-post level of simplicity to jump on a 50kph electric skateboard and off you go.
Last word, I promise: 50kph is scary. All of you downhill longboarders who have earned your way through the school of hard knocks know this. For the rest of us, 20-25kph is plenty fast and hard to react on if you haven't learnt to ride on a non-powered longboard or skateboard. Have fun, and take it easy!
Re: A guide to building a fast electric skateboard at home
#96My suggestion to those of you that are interested in this sort of thing: make sure you know how to ride a skateboard the old fashioned way first. I grew up in Southern CA, skateboarding nearly everyday, to school, back, for fun, etc. There are a lot of basics that you'll want to pick up at slower speeds (how to bail, dodge pebbles, speed wobbles, slowing down, running from rental cops, etc). Chief amongst these is "h…
I can use a normal skateboard, but there’s no easy way to brake other than use your legs or “eat shit”. Not great for your knees. Electric skateboards (one I have) has regenerative braking and it’s amazing. Being able to control your speed is a pretty big feature.
Re: A guide to building a fast electric skateboard at home
#97Earlier quoted context omitted.
There are some exotic cars that use GPS to measure their speed to save weight by not using a typical speedometer.
Do you have a source for this? It doesn't seem to make any sense because the speed sensor is normally used as an input for the engine and brake control systems. Not to mention the fact that the sensor is already extremely light because it's just a rotary encoder. GPS is also wildly inaccurate for speed measurement at low speeds and near tall buildings. I can certainly see using it in addition to a normal speed sensor…
I'd expect to use this 4-wheel sensor data along with the multi-axis acceleration data to calibrate the GPS, not the other way around.
Re: A guide to building a fast electric skateboard at home
#98Earlier quoted context omitted.
There are some exotic cars that use GPS to measure their speed to save weight by not using a typical speedometer.
Do you have a source for this? It doesn't seem to make any sense because the speed sensor is normally used as an input for the engine and brake control systems. Not to mention the fact that the sensor is already extremely light because it's just a rotary encoder. GPS is also wildly inaccurate for speed measurement at low speeds and near tall buildings. I can certainly see using it in addition to a normal speed sensor…
Re: A guide to building a fast electric skateboard at home
#99Earlier quoted context omitted.
I used to ride a longboard through the city all the time, not for tricks, but for transportation, is that wrong too? Also, electric skateboards look hella fun to me. Edit: This post reminds me of people laughing at me and telling me I hold my board wrong, because I 'mall grab'. Why can't you just be happy that people want to ride a board, there's no need to be a snob about it.
Haha, I thought of "mall grabbing" too when I read his post. Electric Longboards are a totally different application. It's like comparing apples to oranges. FYI I come from a background with experience in Snowboarding and Wakeboarding and that's what an eboard feels like except we're not restricted to water/snow anymore. This is great for people like me who have office jobs/family and just want to shred for a few hou…
Re: A guide to building a fast electric skateboard at home
#100Earlier quoted context omitted.
I used to ride a longboard through the city all the time, not for tricks, but for transportation, is that wrong too? Also, electric skateboards look hella fun to me. Edit: This post reminds me of people laughing at me and telling me I hold my board wrong, because I 'mall grab'. Why can't you just be happy that people want to ride a board, there's no need to be a snob about it.
Haha, I thought of "mall grabbing" too when I read his post. Electric Longboards are a totally different application. It's like comparing apples to oranges. FYI I come from a background with experience in Snowboarding and Wakeboarding and that's what an eboard feels like except we're not restricted to water/snow anymore. This is great for people like me who have office jobs/family and just want to shred for a few hou…
For the record, I don't hate on longboards in any way. My point was that it seems that eboards take away from the actual skating experience. It's not a matter of doing tricks and such, but more about the act of skating. The balance of body with the board against the force your body exerts, the feeling of the momentum gained by said force, the ground feel between you and the board in combination with the pushing foot with ground, and the control and freedom that comes with it. My feeling is that electric skateboards take away from the feeling that comes with skating, which is what makes the experience for most who do. But from observation it also seems to handicap some (not all), seeing that many appear to be off balance and unable to really control their electric boards when needing to come to full/immediate stops.
But again I do like your counter point of it being a mode of transportation that's like a bike in terms of speed and energy costs, but allows for the rider the convenience of picking up and moving along