built advice with battery C for 4KW kit and T5 pulley

[minde28383]

Hello Community,
It my time to build E-longboard.

I'm worried that C rating ie 20C 2x3S 500mah is not enough for 4KW (2 x 2KW motors) kit. My pulleys would be 12T 36T, wheels 76mm. Should I return my current batteries and go with the same but 25C or 30C batteries instead?

And do you know if T5 pulleys are suitable for e longboards? In my understanding T5 has advantage over HTD because they are from lighter metal hence whole board will be lighter in the end.

Parts list:
Mindless Maverick Talisman Longboard, Mindless 78A 76mm wheels, Mindless 7inch trucks
T5 pulleys 12T, 36T and belt for it
Two Flymax S3 5000mah with 20C
Alien 4KW kit (2 x 2KW motors and Alien 150Amps controller).
My own custom made motor mounts

 

[777arc]

I assume you mean 5000 mah. Are you using one battery per motor? I'm using the same batteries, but two in series per motor, so 6S per motor.

I don't think the weight from the 2 pulleys and belt is significant. You can get "Polycarbonate, Fiberglass Reinforced" pulleys from sdp-si which will be lighter and cheaper than metal. I would stick to 5mm HTD.

 

[torqueboards]

A lot of people use 6S 5000mah packs at 20C. 100 Amps. It's enough for most people especially flat ground.

However, with 1:3 gearing. You won't go that fast. You should be able to get to around 1:2 and be able to still climb hills on 6S.

50 amps for motor x 22.2v (6S) = 1110 watts or so per motor.

If you really want to reach 4KW. You will need a lot more power. Opt for 10/12S.

50 amps for motor x 37v (10S) = 1850 watts per motor x 2 = 3700 watts -- which is more then enough.
50 amps motor x 44.4v (12S) = 2220 watts x 2 = 4440 watts

The Alien motors have max amp of 60 amps. 12S isn't rated/tested recommended but I think you can use 12S. I've been waiting to try but still waiting on my HK shipment.

60 amps x 37v (10S) = 2220w each motor with a 6374 Sk3 motor.

This is all just my own opinion. If I'm wrong, someone please correct me.

You can go higher voltage and/or higher amps but you would need bigger motors which can take higher amps such as 6374 SK3 motors or similar.

Dual motors help. I'm able to still go uphill here in San Francisco with dual 50mm motors on 6S with 1:2 gearing. Granted some hill climbing is a bit tough because of the gearing and/or takes a heavy kick to get the motors spinning. It does climb relatively well. 1:3 gearing works better and is able to climb hills much easier. The downside is the top end is relatively low unless I increase voltage and/or max amps. That's using 6S 5000mah 20C Zippy Flightmax 3S packs. I've been using 8S with higher gearing to climb hills easier but am waiting on pulleys and will drop gearing down back to 1:2. I like the top end better and/or increase my voltage.

I think increasing voltage is a better option as you won't end up burning out a motor and/or running it close to max IMO.

I would also use HTD 5mm.. Unless you wanted to test T5 --- if you do please let us know on your results and findings.

You can always shave weight off of aluminum pulleys from the sides.

As far as returning your batteries for 25C-30C packs.
6s 5ah 30C will only give 150amps.

With a max of 60 amps per motor. You still cap out.
60 amps x 22.2V = 1332watts x 2 = 2664 watts
It would work if you had 4 motors lol = 5328 watts with 240amp draw

In other words, you settle for 6S and only putting out 60 amps for motor x 22.2v (6S) = 1332 watts or so per motor or 2664 watts for two motors.

That doesn't count inconsistencies either so it will most likely be a bit lower too.

I can tell you though that (2) 6S with 6S 5ah 20C will pull 250 lbs up a 20% grade hill or so perhaps higher with a big initial kick.

 

[minde28383]

I assume you mean 5000 mah. Are you using one battery per motor? I'm using the same batteries, but two in series per motor, so 6S per motor.

I don't think the weight from the 2 pulleys and belt is significant. You can get "Polycarbonate, Fiberglass Reinforced" pulleys from sdp-si which will be lighter and cheaper than metal. I would stick to 5mm HTD.

Hi 777arc,
I too plan to use two batteries in series ie 6S per motor. As you say weight is not significant but still, I prefer lighter if possible.
I thought it twice and won't be using T5. As T5 pulley has not rounded teeth ie has edges so I think that's the main reason why most folks use HTD pulleys.
Per my findings from my local shop pulleys weights are as follow (HTD pfd attached):
HTD 12T 9M - 28 grams (steel pulley)
HTD 36T 9M - 324 grams (steel pulley)
If my board had bigger wheels, at least 83mm wheels than i would go for 44teeth pulley which is made from aluminium and is only 170 grams.

By the way how strong or weak would be Polycarbonate Fiberglass Reinforced pulley compared to aluminium? Is it safe to use Polycarbonate pulleys for E board?
If Polycarbonate pulley is ok then I might inquiry my local shop if they can supply me with these.

 

[minde28383]

A lot of people use 6S 5000mah packs at 20C. 100 Amps. It's enough for most people especially flat ground.

However, with 1:3 gearing. You won't go that fast. You should be able to get to around 1:2 and be able to still climb hills on 6S.

50 amps for motor x 22.2v (6S) = 1110 watts or so per motor.

If you really want to reach 4KW. You will need a lot more power. Opt for 10/12S.

50 amps for motor x 37v (10S) = 1850 watts per motor x 2 = 3700 watts -- which is more then enough.
50 amps motor x 44.4v (12S) = 2220 watts x 2 = 4440 watts

The Alien motors have max amp of 60 amps. 12S isn't rated/tested recommended but I think you can use 12S. I've been waiting to try but still waiting on my HK shipment.

60 amps x 37v (10S) = 2220w each motor with a 6374 Sk3 motor.

This is all just my own opinion. If I'm wrong, someone please correct me.

You can go higher voltage and/or higher amps but you would need bigger motors which can take higher amps such as 6374 SK3 motors or similar.

Dual motors help. I'm able to still go uphill here in San Francisco with dual 50mm motors on 6S with 1:2 gearing. Granted some hill climbing is a bit tough because of the gearing and/or takes a heavy kick to get the motors spinning. It does climb relatively well. 1:3 gearing works better and is able to climb hills much easier. The downside is the top end is relatively low unless I increase voltage and/or max amps. That's using 6S 5000mah 20C Zippy Flightmax 3S packs. I've been using 8S with higher gearing to climb hills easier but am waiting on pulleys and will drop gearing down back to 1:2. I like the top end better and/or increase my voltage.

I think increasing voltage is a better option as you won't end up burning out a motor and/or running it close to max IMO.

I would also use HTD 5mm.. Unless you wanted to test T5 --- if you do please let us know on your results and findings.

You can always shave weight off of aluminum pulleys from the sides.

As far as returning your batteries for 25C-30C packs.
6s 5ah 30C will only give 150amps.

With a max of 60 amps per motor. You still cap out.
60 amps x 22.2V = 1332watts x 2 = 2664 watts
It would work if you had 4 motors lol = 5328 watts with 240amp draw

In other words, you settle for 6S and only putting out 60 amps for motor x 22.2v (6S) = 1332 watts or so per motor or 2664 watts for two motors.

That doesn't count inconsistencies either so it will most likely be a bit lower too.

I can tell you though that (2) 6S with 6S 5ah 20C will pull 250 lbs up a 20% grade hill or so perhaps higher with a big initial kick.

Hey torqueboards,
In that case I’m good with 6S 5000mah 20C.
According my calculation with 1:3 (12T : 36T) theoretical speed with 270kv motors should be 17.8mph (28.5kmh). Maybe it’s little bit slow, might need to increase it by a few mph by adding bigger 14teeth drive pulley. But then again don’t know how 76mm wheels goes over 30kmh on asphalt on my high deck. We’ll see, I’ll get 14T and 36T.
And thanks for clarification with wattage. I’ll stick with 6S 1110 watts per motor and if I’ll need to increase speed in the future I’ll make it 8S as the Alien controller I plan to use supports 8S.
All my imagination about wattage for e longboards is hard to determine for myself because I never stood on electrified board. I know what it feels to have for ex 1000 watts on bicycle but what it means to have for ex 2000w for e longboard I’ve no idea. I guess one thing is to image and another to experience it and nobody around me has e longboards so I can just to speculate and guess what I would be happy with. Firstly I wanted to go with one motor but then again folks write that dual is more torque and where I live there are few long hills which I plan to ride.

Regarding T5 and HDT pulleys.
That’s why I wanted to use 36T T5 because it is from aluminium (not steel) and I could work easier with hand tools with aluminium parts. But don’t want to use T5 anymore because they have no rounded edges as HTD pulleys do.

And thank you both 777arch and torqueboards for replies.

 

[torqueboards]

Htd 5mm comes in steel or aluminum. A lot in aluminum.

 

[minde28383]

Htd 5mm comes in steel or aluminum. A lot in aluminum.

Good to know that HTD 36teeth pulley comes in aluminum too as for me so far only steel was suggested by suppliers.

 

[torqueboards]

If your in USA, Check sdp-si.com.

They have a ton in aluminum.

 

[777arc]

Yeah get aluminum, I only got polycarb/fiber to save a few bucks.

 

[minde28383]

I'm in Europe, Unfortunantly i can't find HTD M5 36T in alumiunium. All my supliers says that their produced HTD M5 36T are in steel unless pulley has 44 and more teeth than they are in aliuminium which would be too big for my 76mm wheels.

What about HTD M3? These are in aliuminium though I don't see them to be on eboards. They have smaller picth but ain't they good to use?

 

[minde28383]

Persistently trying to find aluminium HTD 36T M5 pulley; in the meantime here is longboard I’ll be using for the project Mindless Maverick Talisman:

116.75cm / 46 inches long
24.75cm / 9.75 inches wide
85.75cm / 33.75 inch wheelbase
Deep concave pin tail shape
6-ply Canadian maple with bottom ply smoked pin stripe bamboo
7” Talisman trucks with polished finish.
87A medium Mojo bushings
Mindless Shifta 76mm 83A wheels
ABEC-9 Chrome bearings
Recommended max rider weight: 20st / 130kg / 280lbs

 

[rs4race]

Are you planning to machine the HTD pulleys to fit to the wheels?

If you have access to a 3d printer you can print them and they will hold up quite well. If you have access to a mill and lathe you can cut them yourself with a 1/8" drill, lathe, and whatever else you need to drill/tap.

I have a set I modified from SDP-SI and another set I printed. They both have several hundred miles on them and still have tight tooth mesh.

If you want more info on either let me know.

 

[777arc]

Likewise, if all you can find is polycarb reinforced with fiber, then buy them and fill in the hollow section with epoxy, and it will work fine. Just make sure to drill the bolt holes in the 36T before filling it in with epoxy, to make life easier.

 

[minde28383]

I'll try to escape machining if possible. Have no access to 3D printing which would be great.

Finally found HTM 36T aluminum pulleys. SKF is the manufacturer. Local company near me distributes SKF HTD aluminum pulleys in various sizes. On Monday placing order for 36T 15mm and 14T 9mm pulleys and two 295mm length belts; but lead time is few weeks; weather getting warmer and I have to wait for pulleys...

Not sure I plan right thing, but my bigger pulley will be 15mm wide and smaller 9mm wide. I thought that my motor mounts will be dyi thus possibly not so precise so in case some displacement between drive and driven pulleys, belt would be still on. Or it makes no sense to have different pulleys widths?

 

[minde28383]

Finally finished my board. As you can see it has currently two motors. I made some testing with two motors and acceleration is insane. I climes very well but is jerky. If I press gas two much it shoots forward to fast, I don't feel comfortable with such power. Maybe it is interesting to play for a while with such power but in practice it does not suit me, thus I decided to leave only one motor and, wow, what a nice ride it is now.

My advice to other would be: go with one motor, less expensive, lighter, less work to if it's diy. 5055 or 5065 or 6050 would be enough.

One more negative thing I experienced with two moors is that it has too much drag. For ex you want accelerate and then to cruise little bit without gas and it slows down too quickly. I prefer ride with less drag as possible. Also brake with one motor is just in spot, not too strong, not too week; apparently braking power can be tweaked with controller settings.

Also tool box for batteries and controller is not good for me. I don't like every time opening box, messing with wires, and than closing it. At the beginning box looked as a nice solution but don't like it anymore. Will think some other way attaching batteries and controller to longboard.

 

[minde28383]

Here is one of my test rides with dual motors: https://www.youtube.com/watch?v=LnjFURCiGOE