Personal Notebook - Am I on the right track - Follow me along the way

ESK8 Electronics
1

Hi Guyes, this forum is giving me so much great info, thanks. :heart_eyes: So, I’m as one of the many, an all time electronic noop that took a project building a skateboard, Made this topic along with my notebook as I’m learning more and more of this world so you guyes can now follow along and look where I am going. :runner: This topic will be updated daily as I’m learning and by my self and you guyes :mortar_board:

Thank you for taking a look and following me along!

:tulip:MY DESIRE :tulip:

Top speed would be around :rocket: 20-25 mp/h (32-40 km/h) :rocket:

A great moderate acceleration/torque for when going from red to green light along bikes and cars. With that torque I want my skateboard to go without needing to push off the gound. But I’m not going to ride the San Francisco streets, most of the streets I’m at in the city is flat as a pancake with two or three hills with a 10-15% rise. Maybe too long explanation about my desired torque, but I hope it makes sense :sweat_smile:

The range should be 10-15 km (6-10 miles)

The wheel size would be 83mm the lowest diameter in the recomended 80-90mm for having the quickest acceleration. :rocket:

The wheel and motor pulley that fits would be these :gear: DRIVETRAIN :gear: Wheel pulley With: 15mm Teeth: 36 Motor pulley Bore: 8mm Theet: 15 Width: 15mm Drive belt Lenght: 265mm Teeth: 53 Fit with 15/36 pulleys Width: 15mm

Motor mount I found this TorqueBoards v4 Bolt On Motor Mount that fits most motors in 63mm and 50mm of diameter. I found this Turnigy Skateboard Conversion Kit Spare Parts - Motor Mount from HOBBY KING :mone €7.26

Link to complete set 80mm

90mm

:motorcycle: MOTOR :motorcycle: I’m joggeling with a lot of motors in my mind, I have a link to them followed by a thought.

KV is the number of rotation of the motor per voltage applied. Usually the higher the KV the faster the motor, and the lower the KV the more torque it can produce.

Motor suggestions 1.Turnigy Aerodrive SK3 - 6364-213kv Brushless Outrunner Motor

2.PROPDRIVE v2 5060 270KV Brushless Outrunner Motor

3.Turnigy Aerodrive SK3 - 6364-190kv Brushless Outrunner Motor :star: I’m going with this one :ok_hand: €73.98

4.Turnigy Aerodrive SK3 - 6374-192kv Brushless Outrunner Motor

5.Turnigy Aerodrive SK3 - 5065-236kv Brushless Outrunner Motor

6.Turnigy Aerodrive SK3 - 5055-280kv Brushless Outrunner Motor

There is such a small difference in the motor and i should just make a quick choice

:cloud_lightning: BATTERY :cloud_lightning: This part have I learned so much about, and still can’t get my head around

Volt - How strong electricity is puched Amp - How much electricity is going buy Watts - How much enegy is consumed per chunk of time Ah - Means longer range mAh - A unit of charge (how much electriciry can be in the battery) (how long it will provide the power) C - is the discharge rate (how quickly it can provide the power)

my battle between the The Lipo (Lithium polymer) VS Li-ion (Lithium ion) have concluted:

:battery: Lipo Cheap (in the shourt term) but understandeble and i thing I would need a 6S and something and 22V (volt) battery or something. I don’t know.

Battery sugestions for Lipo 1.ZIPPY Flightmax 8000mAh 3S1P 30C Lipo Pack

2.ZIPPY Compact 5000mAh 5S 25C Lipo Pack Seames nice but is too bit, looking for a flatter one

3.Turnigy nano-tech 6000mah 6S 25~50C Lipo Pack

:battery: Li-ion Battery sugestions Link to understanding the S and P I’ have no pack solution but have read that SAMSUNG 30q cells from ru.nkon.nl but witch one and how many is a myth for me. If I knew how many Li-ions I sould get to have the same as my Lipo battery suggestions above. For a longer use of battery and the safty of not having Lipo battery explode. Or find a good battery pack with a battery management system (BMS)

:robot: VESC :robot: Unik control HW 4.12 Is expensive but seems like a god choice. 124,17€

Electric skateboard Speed Controller (Maytech) Cheap, but not the best quality

:control_knobs: CONTROLLER :control_knobs: Enertion Nano-X 2.4Ghz Controller $116.00 The design and quality looks great but i prizy The only one I like and pretty sure to go with that.

:railway_track: TRUCK :railway_track: Any Caliber truck, to mount motor Or the one from Hobby King 30$

can see that it all runs up in prize, have not calculated it all yes, but it may be cheaper to buy a boosted board :sweat_smile::sweat_smile::sweat_smile:

:notepad_spiral: I HAVE A CHECK LIST :notepad_spiral:

To :ok_hand: all my 6 KEY ELEMENTS 1. Wheel pulley With: 15mm Teeth: 36 2. Motor pulley Bore: 8mm Theet: 15 Width: 15mm 3. Drive belt
Lenght: 265mm Teeth: 53 Fit with 15/36 pulleys 4. Motor Turnigy Aerodrive SK3 - 6374-192kv Brushless Outrunner Motor 5. Wheel 83mm 6. Battery Don’t know What Li-ion battery pack with a BMS and on/off switch would you take? or should I make it my self

To :ok_hand: all my 6 VARIABLS V1. Gearing Reduction Ratio - I know what gear I want but what GRR number they make. V2. Motor KV - 190kv :ok_hand: V3. Battery Voltage - ? V4. Wheel diameter - 83mm :ok_hand: V5. Desired top speed - 20-25 mp/h (32-40 km/h) :ok_hand: V6. Desired range - 10-15 km (6-10 miles)

Is it all too much info in one topic?, this is my first post, let my know how I can make this better. This is again just a way for me to get an overview. Feel free to comment

:pencil: EXTRA NOTES :pencil:

:gear: Gear ratio

A gear ratio of 2:1 means (motor rotation:wheel rotation)

As in every time the motor has made 2 turns, the wheel has made one turn.

:motorcycle: Motor Turnigy Aerodrive SK3 - 6364-190kv Brushless Outrunner Motor

SK3 is just the brand

6364 is masuremenets of the motor (63mm x 64mm)

190kv means RPMS (Rotations per minute) per volt

T18 is mentiont in lower in the description of the motors site same link as above. what T18 gives you is the lower the T number is the higher the RPM you can expect from the motor

P14 is poles (magnets) insode the motor

See you ! じゃあね！

2

A few rules to help you understand the electro part Ohm’s law: V [volt] = R [resistance] * I [ampere]. Power: P [watt] = V [volt] * I [ampere] Ah = 1000 mAh. m in this sense is milli - milli Ampere hour.

Examples: If you have a 10s4p battery you may have (depending on batterytype) 36V * 12Ah = 432 Wh power.

Some more rules/basic electro: Putting two power sources in parallell: two 3.6V 3Ah batteries results in a 3.6V and 6Ah batterypack.

Putting two power sources in series: two 3.6V 3Ah batteries results in a 7.2V and 3Ah batterypack.

Hence a 10 in series and 4 in parallell batterypack with 3.6V and 3 Ah batteries is 3.6V * 10 = 36V and 4 * 3Ah = 12 Ah.

1 Like
3

In general are LiIon batteries safer than LiPo batteries. Are you planning on building the batterypack your self? You can buy a complete pack with a BMS from one of the DIY-vendors. In Europe you can look at, among others, Unik Boards and esk8.de.

There are many different setups. You need to figure out what suits your final configuration. Try the esk8 calculator to learn some of the parameters: http://calc.esk8.it

Referring to the examples in the last post, you will need 40 LiIons 18650 batteries for a 10s4p batterypack.

5

What is ment by the Efficiency?

6

Your esk8 system is not ideal. In other words, you do not get all the power from the battery directly in to moving you forward. There are several matters that makes a system less than 100% efficient: different friction in e.g. belts and bearings. In addition there are efficiency losses in the electronics.

What exactly the efficiency rate is I cannot answer as I have no numbers to back me up. I can say that it is less than a 100%, for sure. Maybe someone else can add some efficiency numbers from experince?

7

I would say leave it at 85 or 90and it should be good

Also, check one.more calc, it.is good for battery / range estimate (though some extra room for battery life would be advised)

http://calc.esk8.today

–

By the way - nice write up of text / description of build plan, very easy to read!

As about the motors, i would suggest to go through calc a few times, over 200kv for 6s might be recommended, unless u gear.for speed. Going with lower like 190kv, is probably a good.idea if u plan to improve / increase.voltage of.your battery in the future

1 Like
8

I dont know half of the things means on that calculator :sweat_smile:

9

Well, if u want more than 30kph speed with 83mm wheels, 6s (22.2v) battery volts and, 2,4 : 1 gear ratio, then you need at least 245kv motor.

I think 2 : 1 gear ratio is possible, but then you would still need at least 236kv motor i think.

Some people who want higher speed with 6s, might even choose 270kv motors

– update –

As you gonna use vesc, go at least with 8 - 10s from beginning, speed will be higher, u will also probably get more torque, as your gearing can be higher (not so much aimed for.speed, as motor will spin fast enough anyways because of extra voltage)

Then with 8s or 10s you can easily go with around 200kv motor and you shouldnt have problems

The only headache u will have is.how.to.charge.batteries, unless u install bms and charge in “bulk.mode” but drawback to.this is not seeing what is going inside of cells.while.charging

10

are you talking about the wheels sould be 85 or 90?

11

No, the efficiency. Though some others might recommend 80 percent but for me 85 - 90 was more believable / precise

1 Like