DIY Electric Longboard Build (Plan!) - Can you confirm it?

[lemon]

Hi,
~3 months ago I made the plan to make my own electric longboard - i've watched a lot of youtube videos and read many things about it.

So now i've got some parts in my list, and wanna know if everythings ok with that, or if i made any mistake.

Motor: http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=18125
Battery: 2x http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=65267 (parallel)
ESC: http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=32466
+ http://www.hobbyking.com/hobbyking/store/__14631__Turnigy_TrackStar_ESC_Programing_Card.html
Radio: http://www.hobbyking.com/hobbyking/store/__83360__HobbyKing_174_8482_HK_GT2B_3CH_2_4GHz_Transmitter_and_Receiver_w_Rechargable_Li_ion_Battery.html

As transmission i wanted to use 16/50 teeth, because this calculator showed me, i'd get 15km+ and 20 km/h out of it. http://www.elektro-skateboard.de/wiki/wissenswertes/strom-spannung-reichweite?Reifendurchmesser=68&RitzelRad=50&RitzelMotor=16&Motorkennwert=430&IAkkuAh=10.4&IMax=25&UMax=11.1&UFahr=11.1&IGrund=0.5&Wirkungsgrad=90&Gewicht=90&Steigung=0&Dichte=1.20&cw=0.78&Flaeche=1.00&cr=0.01

So i think that was it, or did i forget anything?

greetz

 

[dannydoyle2]

Batteries are okay, so is the Transmitter.
For the motor, I'd go for something with a lower KV rating. Yours is 430KV which technically is possible, but somewhere in the range between 150kv-300kv would probably be better for you. More torque.
Your ESC won't be enough though, since it's rated for only 25A and your motor (or any other 50+mm motor with <400kv for that matter) will draw way more than that. You should aim for an ESC with about 20% more amps than your motor spec says it will draw. Just make sure it's a car ESC and not an airplane ESC, because those won't support braking and acceleration is usually also way too harsh.
I'd go for the Hobbyking 1/8 120/150A X-Car ESC that you can also find on hobbyking. That one also has an on-off switch, which saves you the trouble of building a spark switch or getting a mosfet based switch that could cost 40-60 bucks extra. Keep in mind that you'll need to buy a programming card for that esc as well, because it doesn't have that beeping programming mode, that other esc's sometimes have. It's only a few bucks extra but still. Other than that it looks alright.

For the transmission, I'd rather aim for 16/36 but that's just me.
You forgot the motor mount

 

[lemon]

motor mount will be handmade

well, i took an 25A esc because the calculator said my system would max out at 12 amps, because 11,1Volts
but if i take a lower kv, the amps will be higher, yes.
can you recommend any motor?
its very important that its not very large, because i have a drop through longboard

edit: and if i take a 200kv motor for example, i go better with 4S, right?
because i want ~20 km/h

 

[sl33py]

I'd recommend you stick with tried and true ESC's to start. That 25a ESC like mentioned will not work. Also make sure any ESC you get the programming card/cable. You will need to adjust the brakes at the very least, if not also other settings.

EZRUN/XERUN/FVT - Or VESC/DIYes 6s/12 ESC's. I'd recommend VESC if you can swing $ it.

Batteries - i would recommend higher C batteries. Those are appealing for cost, but at only 10c - they have a constant 52 Amp capacity which is *theoretical* and if overdrawn in reality will affect pack life. I typically target a 100A target at a minimum - knowing that i'll usually only draw 30-50A peak. This extends pack life and to ensure that they can realistically provide the amps needed (vs what their marketing department claims).

motors - i like around 200kv setups, but also usually run 8s. So if you are limited to 6s or lower (Car/Hobby ESC's) - i'd look at the SK3/Tacon bigfoot motors (63mm) around 200-245kv.

 

[lemon]

Well, i use them in parallel, so they're 104 Amps, and i think thats enought, if the ESC can handle 100A max and the motor 70-80A max.

So i switched to http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=41741 with a programming card, but which motor should I use?
Hobbyking has nearly no low kV motors in stock

and because i'm on a low budget, i can't use a vesc

 

[sl33py]

in parallel you are only going to have 3s - that's not going to be enough. You will want 6s (2 in series).

If you are looking at that new ESC - can you swing the extra $ for one of DIYes 120a 6s ESC's and programming cards? You might be able to find the non-DIYes branded FVT 120a 6s ESC's for less too.

DIYes - http://diyelectricskateboard.com/diy-electric-skateboard-kits-parts/single-motor-120a-6s-esc/
($70 + $15 programming card)

FVT elsewhere - http://www.rcjuice.com/fvt-120a-brushless-sensored-sensorless-car-esc-2-6s.html
($56 + $25)

80 vs 85, i'd get it from DIYes for the service and to support the community.

If that's still out of your budget - check out the online marketplace here and on esk8 builders to see if someone has a FVT/EZRUN/XERUN used?

I understand being on a budget, but i'd look to save a few $ where you can to get a good ESC. Batteries - i'd get higher c batteries even if lower mAh (capacity) to save $. Shorter range, but you can add more in parallel later as $ allows.

Where are you located? I might also check local craigslist for a mamba xl2 or EZRUN/XERUN ESC's.

Hope this helps.

 

[lemon]

Well, the problem is, 6S is more expensive.

And if i take 400kv with 3S i get the same speed than 200kv 6S.

I know i would get more range and torque with 200kv and 6S, but i cant find any good 200kv motor in stock on hobbyking (europe warehouse)

As i mentioned before i have a drop through longboard, so i cant take a 60mm motor, because i only got 70mm from the board to the ground.

 

[lemon]

The only thing near to 200kv i could find was this 300kv one http://www.hobbyking.com/hobbyking/store/__37268__Turnigy_G60_Brushless_Outrunner_300kv_60_Glow_EU_Warehouse_.html

but if i go 6S with that i have to use something like 15/60 gear

if i do 3S and 430 kv i can do 15/45 (45s are easier to find here in germany)

but there is no 200kv motor under 50mm diameter, so i cant use 6S.

if i would take 6S with the 430kv motor i'd have to do 15/90 (and i think thats not really possible)

 

[sl33py]

I wish i were in europe most of the time, except when it comes to parts - and the ridiculous import fees!

I haven't heard of anyone getting a decent running esk8 w/ 400kv setup. done - probably. But maybe not as nice especially to start.

Humor me for a second? What's your budget?

 

[lemon]

I dont really want to spend much more than 200€

50€ motor
30€ batteries
50€ esc
30€ radio
5€ case for the stuff
15€ motor mount

so theres only 20€ left

if i would take 6S my budget is exhausted, but then theres the problem with the motor..

what i could do, is add some more budget for this motor:http://alienpowersystem.com/shop/brushless-motors/alien-5065-outrunner-brushless-motor-270kv-2200wa/
but i think 60A is a little low?

Do you know any good shop which got motors in the eu/uk?

and maybe i could put a little amperemeter in there to see my actual power drawing https://puu.sh/qwdB7/85eddc349f.JPG

And maybe i could use 4S, not 6S, because i dont want to go really fast, i want a fiat, not a porsche

 

[WeeChumlee]

Hi
Unless you weigh about as much as your board and only want to ride on super smooth a totally flat surfaces I would recommend you seriously reconsider your choice of motor and battery.
With a 400KV motor running on 3S voltage you have a nice radio controlled skateboard - just don't think you can actually ride the thing with any satisfaction.
I appreciate you being on a budget but still wanting to build something, that is commendable. What we really want to avoid is that you blow your budget and at the end have a 200 Euro skateboard shaped radio controller car.

 

[lemon]

how many people want to say that again?

I GOT IT - 3S WITH 430kV DOESN'T WORK

sorry if i'm a little pissed, but this helps in no way, even not if 2 people before you already mentioned that and gave me alternatives, which i already switched to.

 

[lemon]

what do you guys think about this motor?

http://www.aliexpress.com/item/5065-50-65-270KV-Heavy-duty-brushless-Sensored-motor-2-6KG-3-8S-for-Skateboard/32681820833.html?spm=2114.30010308.3.19.o7oRyo&ws_ab_test=searchweb201556_0,searchweb201602_5_10057_10056_10055_10037_10049_10033_10059_10058_10032_10017_10060_10061_10062_10063_412_10064,searchweb201603_8&btsid=b3877f01-f044-45eb-8b78-1901c318fe56

Or does anyone know where the NTM Prop Drive 5060 270KV is in stock? I'd even buy it from china

 

[WeeChumlee]

Chill dude, only trying to help. You did not say you had changed already, all I see are "if", "could" and "maybe".
I was stressing the point to make sure you did not make the same mistake many have.
I am glad you "GOT IT"

Go with the Alienpower 5065 instead of the one from Aliexpress.
And still go with 6S - do not got lower as I think you will be disappointed.
FVY120 would probably be the best ESC on your budget.
As you are in Germany, have you looked at http://esk8.de/ (If only for inspiration)

 

[lemon]

hmmm ok..

can i take this motor? http://www.hobbyking.com/hobbyking/store/__37268__Turnigy_G60_Brushless_Outrunner_300kv_60_Glow_EU_Warehouse_.html

its 30€ cheaper than the alienpower and has only 30kv more.

my problem now is, the 6S batteries i want are out of stock and they are too big for the case i have

is it possible to put a 4s and a 2s in series? both are in stock and fit into my case

 

[sl33py]

Appreciate WeeChumlee chiming in - he knows what he's talking about.

I wanted to see what your budget was so we can try to find some alternatives to recommend.

I personally would not go higher kv than 245-260 if you can. that 270 being sensored would help (if your ESC supports sensors). If you don't use the sensors - no big deal, but a nice option you can leave unconnected till later.

On a super tight budget you might need to wait for some back-ordered batteries to come in. Here's some i think would work well and are about $24ea. Yes, they are a bit above your budget, but you need 6s and 5000mAh would be the least capacity i'd recommend for any decent range. I would skimp on other items, or get some used, to make up the difference.

Motor - i'd keep hunting. The ali 270kv might work, but i'd look through the for sale section here and on esk8 builders to see if you can score a used motor for a decent price. targeting the 230-270kv or less. Not going to be super powerful or fast on 6s, but a good motor you can use later at higher voltage or w/ another ESC is a good thing. I have a 200kv 63mm motor, but i beat up the shaft a bit getting a stuck gear off - might be willing to donate it to the cause - shoot me a PM and we'll chat. Wouldn't be charity/free, but something reasonable.

ESC - and Radio - GT2b for radio. You might not be able to put in a smaller enclosure right away, but rock solid connectivity and control are great, with rechargeable batteries and just one of the best. about 23-25 from HK. You know to wait before you click buy right? They will frequently pop up a small "get it now for less" and save a few $. I keep going back (even another browser if i missed it) until i see this. It adds up (savings)!

ESC - the least expensive one i've found that i have no experience with to be honest - is the x-car 120a. Looks similar to FVT, and the programming card is 15, with smaller LCD programmer for 5-6!
http://www.hobbyking.com/hobbyking/store/__77144__HobbyKing_174_8482_X_Car_Beast_Series_ESC_1_8_Scale_120A.html

lists as $52, but waiting i got a "buy it now" offer for $48!

helped getting your budget - probably still a bit above what you want to spend, but i'd recommend being patient and looking at some select used items vs building something that just won't work!

HTH - GL!

 

[lemon]

Thanks for that long text

But this still gives me some questions..

1) whats better on 6S @ 5000mah than 4S @ 10000mah?
2) whats better on a sensored motor?
3) whats better on that esc you send now than the http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=41741 ?

thanks for the motor offer, but 63mm is too big for me, as i have a drop through longboard which is ~6-7cm above the ground, maybe i even need to put the motor on the other side so it cant touch the board, but i will try to montage it under the board first.
i really think i'll take that one from aliexpress, price is ok and its sensored

I was already planning to buy the GT2B and a friend of mine got a 3D printer, so i will use the BadWolf GT2B Case mod v2

 

[sl33py]

Thanks for that long text

But this still gives me some questions..

1) whats better on 6S @ 5000mah than 4S @ 10000mah?

it's about voltage - higher voltage = less amps and more "punch" to the motor. More power - which you need to move a human vs RC Car. 6s would be the minimum i'd recommend. It will run cooler with less amp draw at 6s vs 4s and give you more usable power. Ah is only relevant to range in this case. 6s 5ah = 111Wh. you can *roughly* expect about 1km per 10Wh - so you should reasonably expect about 11km/6-7mi from this setup. On the flats and you aren't racing around or super heavy.

2) whats better on a sensored motor?

When you start off most ESC's will "stutter". A sensored motor knows RPM's from the sensors feedback and are much smoother starting. VESC is the best i've tried that has little to no stutter even without sensors. You will need an ESC that has sensored input. It's not a silver bullet and there are other issues, but starting and hill performance are supposed to be improved w/ sensored. There's a ton of other info to read up on, but that's my basic understanding.

3) whats better on that esc you send now than the http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=41741 ?

It looks like a re-badged FVT 120a which folks have some experience using. Vs the one you linked which looks much more cheaply built. Just make sure you get a programming card with either. you *MUST* adjust at least the brakes!

thanks for the motor offer, but 63mm is too big for me, as i have a drop through longboard which is ~6-7cm above the ground, maybe i even need to put the motor on the other side so it cant touch the board, but i will try to montage it under the board first.
i really think i'll take that one from aliexpress, price is ok and its sensored

I was already planning to buy the GT2B and a friend of mine got a 3D printer, so i will use the BadWolf GT2B Case mod v2

No worries. I'm happy to hold onto that motor in case the other one on my GF's board has any issues. GT2b is a great radio - you will love it once it's in badwolf. A note on the badwolf enclosure - the walls are too thin IMO. I would check out the flatline customs "mad monkey" or baby buffalo enclosures before you swap the GT2b into new smaller enclosure.

Hope that helps and good to see you are adjusting to a different setup with our feedback. Look forward to seeing the build next!

 

[lemon]

Ok that sounds good

(I hope) final question: is the ESC cutting off at 120A, or could it be possible that when i use it for something else it would handle 200A or so and would overheat?

rest in rip english

 

[WeeChumlee]

Personally, I think that G60 motor is too small and not powerful enough. I think it would probably overheat but that is of course just an educated guess.
The HK ESC you posted only goes to 4S so I would not try that one because, as sl33py says, it is not just the mA/h but the voltage that counts.
Better: http://www.banggood.com/de/FVT-CBWI120A-ESC-Brushless-Speed-Controller-For-110-and-18Series-RC-Cars-p-985970.html
Batteries, best I could find that will give usable range @ 6S : http://www.hobbyking.com/hobbyking/store/__9183__Turnigy_5000mAh_3S_25C_Lipo_Pack.html

I had this motor: http://alienpowersystem.com/shop/brushless-motors/alien-5065-outrunner-brushless-motor-270kv-2200wa/ and the FVT120A ESC driven by a 6S 8000maH battery on a board and that was a decent and light board. For popping around it was great, not good on hills but not too terrible either and I am nearly 90kg.

 

[WeeChumlee]

I doubt it has an internal current measurement but may have a thermal trip.
The MOSFETs within though may well only be rated to 120A (constant)- so if 200A was asked of them them may well pop. At the very least they will overheat extremely quickly.
If 200A was drawn for a very short period of time it would be OK. They have a peak rating above that - but I would advise against trying.

 

[lemon]

wups i didnt see the max voltage on that hobbyking esc.

ok i now ordered this motor: http://www.aliexpress.com/item/5065-50-65-270KV-Heavy-duty-brushless-Sensored-motor-2-6KG-3-8S-for-Skateboard/32681820833.html

it got the same specs than the alienpower motor, so it should not be that bad
(especially because i got it for 37€, the alienpower would have been 80€)

then i will buy this esc: http://www.banggood.com/de/FVT-CBWI120A-ESC-Brushless-Speed-Controller-For-110-and-18Series-RC-Cars-p-985970.html
(which programming card do i need for that?)
+ http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=36297

And i will take 4S lipos (sry guys ) first.
i will test it, and if it's not good i will send them back and get 6S
thats because i've seen some people on youtube taking 4S with 270kv motor and they were very satisfied.
especially because i prefer range over speed

then i'll take this ammeter for monitoring: http://www.ebay.com/itm/172157792991

then i'll grab a gt2b and do the motor mount on my own, get 2 pulleys and a belt..

and that was it, i guess? do i need some antispark connectors? or another on/off switch or can i use that one from the esc?

 

[Njakts]

Anti spark switch is not needed, there is going to be a spark (little spark) when connecting battery to esc, but after that you can use on off switch on esc.
what drive ratio do you plan to use? And what size wheels are you going to use?

 

[lemon]

68mm wheels and the pulleys be like 16/40 on 4S, if i should switch to 6S 16/60

 

[WeeChumlee]

You can use a XT90S connector as a spark arrestor. Works very well and I actually removed the electronic anti-spark switch I had in one of my boards as the XT90S worked well and was smaller.
(But as Njakts said not altogether necessary)
For that price the motor is worth trying out - easiest part to upgrade later if needed.

Programmer for FVT is this I believe
http://www.banggood.com/RC-Car-Program-Card-For-FTV-Series-Car-Brushless-ESC-USB-Link-Card-p-985974.html

Do you have the shunt resistor for the Ammeter?