Need help to build a hand throttle

zeroonea

10 mW
Joined
Oct 13, 2017
Messages
24
Hello, I'm very newbie in RC and electric scooter. I need help to wire a throttle system. I already bought these things:

ESC: https://www.banggood.com/TSKY-120A-110-18-6v-ESC-Senseless-BrushlessSense-Brushless-RC-Car-Part-p-1088705.html
Brushless motor: https://www.banggood.com/Racerstar-6368-BRD6368-280KV-6-12S-Brushless-Motor-For-Balancing-Scooter-p-1117657.html
Servo tester: https://www.banggood.com/Servo-Tester-Third-Gear-Switch-With-Indicator-Light-4_2V-To-6_0v-p-1079862.html?rmmds=search
hand throttle: https://www.banggood.com/24V-36V-48V-Twist-Throttle-Grip-78inch-Handlebar-3-Wire-Electirc-Scooter-Bike-p-1032851.html?rmmds=search

Is it enough parts? How to wire them together?
 
How are you going to get the reduction needed to drive a scooter with that little motor?

The quality of that stuff is suspect to say the least. I wouldn't personally use it on a ebike. The throttle is total junk and not precise and high resolution. Domino is much better throttle if you can find it.

You need to make the servo tester vary its output according to the signal your hall throttle sends out. If no one here can tell you how to do that hit up EEVblog forums. One simple and inexpensive way is to use an arduino. This lets you bypass the servo tester altogether.

Also a Cycle Analyst V3 can take your throttle as input and output the correctly encoded signal for the servo...meaning you don't need to use the servo tester.
 
The guy here use even smaller motor but still good speed for his e scooter: https://www.youtube.com/watch?v=3X8Uf4rAEDk

I will check the blog
 
The ESC is rated up to 3S (~12V). 6V is the BEC or Battery Eliminator Circuit. The higher the voltage, the less current is needed. . In theory, a 10V 100A setup and a 48V 20A setup will perform the same (with appropriate gearing), as they are both ~1000W. In practice, higher currents are less desirable as they contribute to more losses and more heat. For e-bikes and scooters, a higher voltage is ideal. I have had good luck with 25V-48V (6S LiPo to 12S).

In principle, an e-bike is simple:
Battery->ESC->Motor
Throttle->ESC

One issue that you will run into, is that the RC ESC that you purchased is designed for servo signal, or PPM. PPM works by transmitting pulses and is illustrated on this example:

https://oscarliang.com/ctt/uploads/2013/11/pwm-ppm-signal-example.jpg

In it's typical configuration, an RC transmitter communicates wirelessly with a receiver, such as this one:

http://i03.i.aliimg.com/img/pb/156/860/255/1278060581579_hz-myalibaba-web-temp1_733.jpg

The receiver converts the proprietary signals it receives from the transmitter and converts it to PPM. As you can see from the image, the receiver has several channels. For RC cars, you need two channels: CH1: Forward/Reverse and CH2: Left/Right. Both a servo and an RC ESC are designed to respond appropriately to PPM (servo signal).

Your throttle is either a potentiometer or hall-effect, but either way, the result is the same: it is a voltage divider. It produces an analog signal. An example of such a signal is in the first image link. Your throttle has three wires, positive, negative, and signal. A potentiometer works by taking an input voltage, such as 3.3V and outputting a variable voltage between 0V-3.3V on the signal wire. In practice, each throttle works slightly differently. My e-bike throttle produces 0.83V-2.55V with 3.3V input.

It was suggested, and I recommend an Arduino if you'd like to use an RC ESC paired with an e-bike throttle for your project. This is a picture of one of my projects where I used an Arduino to convert an analog signal to PPM:

https://imgur.com/4s4Kgad

Your motor was tested for 1kW-3kW, which is sufficient for an e-bike/scooter project. I have used a motor like yours (same size, power rating) and achieved unassisted speeds of 35mph. Just monitor temperature. Because your motor is rated for 6S - 12S, and your ESC 1-3S, I would recommend upgrading your ESC. There are a lot of options out there. I would recommend the VESC or FOCBOX.

http://www.enertionboards.com/electric-skateboard-parts/FOCBOX-programmable-brushless-motor-controller/
https://diyelectricskateboard.com/collections/featured-items/products/torque-esc-vesc-bldc-electronic-speed-controller

The FOCBOX is based on the open-source VESC, both are highly-configurable and have GUI configuration programs for Windows and Mac. With either of these, you have the option of connecting your throttle directly to them using ADC mode.

Let me know if you have any questions and I'd be happy to help any way I can. Good luck!
 
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