ACDC
ACDC | |
---|---|
[[File:|thumb]] | |
Built By | Vince Williams |
Theme | ACDC |
First Race | Scrumpy Cup 2019 |
Current Status | Active |
Motor | 2kw Brushless BOMA, AliExpress |
ESC | 1500W 48v ebike Generic controller, AliExpress |
Battery | 48V 12S LiPo (2x 6S) |
Transmission | |
Contact | @Bodgecharger |
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Background
ACDC is my second generation Hacky Racer build. I built this racer based on all the lessons I'd learned from racing my original racer (Bodge Charger), i.e it was too tall, too narrow and too unstable. So ACDC is built to have as low a C of G as possible with a wider track than Bodge Charger giving superior handling in corners, this means I don't need to slow down so much in the corners. The chassis is 1500mm long (max allowed at the time of construction) and the width is determined by the widest I could possibly make it and still be able to roll it down the pathway at the side of my house.
This photo is of ACDC running at Fully Charged at Farnborough in 2022 where it did really well in all the races.
Construction
The base Chassis is a mobility scooter with the original front axle.
Motor and Drive
Steering
Wheels and Tyres
Brakes
Motor
Motor - ACDC uses a single 2kw BOMA scooter motor from AliExpress. The motor is mounted so that it can be rotated 180 degrees to provide drive to either the LH or RH axle depending on the track direction (clockwise or anticlockwise), this means that ACDC is configured as a single wheel drive racer. This has its advantages and disadvantages, the advantage being that the car needs no diff and there aren't any steering issues like you typically get with a fixed rear axle configuration; the disadvantage is that there's usually one corner on the circuit where the wheel lifts, spins and you lose drive. But overall, single wheel drive works really well.
Controller
ACDC uses a generic 1.5kw E-bike controller from AliExpress. These Chinese E-bike controllers are bullet proof, powerful and cheap. There's no reason to use anything else to drive the 2kw BOMA motor.
Batteries
ACDC uses 2x 6S 10ah Multistar LiPos from Hobbyking for races. I did try some custom 20ah EIG Li Ion cell packs in a 12s configuration, but these felt less powerful overall and the voltage sagged more than the LiPo packs.
Drivetrain
The gearing ratio depends on the drive wheel diameter and the speed you wish to achieve. Top speed isn't the most important thing in a Hacky Race, acceleration out of the corners and torque are the driving factors. I have geared ACDC to run a top speed of 20 mph, this is plenty fast enough for the short tracks we tend to use for races and is a good balance that gives decent torque and acceleration. With my Go-Kart wheels and tyres I use an 11 tooth cog on the motor and a 74 tooth cog on the drive axle to achieve a calculated top speed around 20 mph.
Other Features
Sound? Lights? Remote steering?
Awards
- Loads!
BOM
Item | BOM Price | Notes |
---|---|---|
Mobility scooter chassis/bodywork | £35.00 | £25 for mobility scooter chassis and £10 for bodywork |
Pillow bearings | £30.64 | |
Axle shaft 25mm | £20.02 | |
Pair of front wheel hubs | £29.99 | |
Pair of rear wheel hubs 25mm | £34.00 | |
Shaft collar 25mm (sprocket) | £3.12 | |
Shaft collar 25mm (brake disk) | £- | Brake Component - Free |
Shaft collar 40mm (sprocket) | £6.72 | |
Shaft collar 40mm (brake disk) | £- | Brake Component - Free |
Pair of Brake Disks | £- | Brake Component - Free |
Pair of rear sprockets | £9.99 | |
8mm T8F chain | £4.25 | |
Ammo box | £- | Free for BoM |
Brushless 2Kw motor | £79.99 | AliExpress, bought in 2020 |
Motor controller | £15.84 | AliExpress, bought in 2020 |
Throttle pedal | £10.09 | |
Steering wheel | £24.99 | |
2x mtb brake set | £- | Brake Component - Free |
Batteries | £- | Batteries - Free |
Switches | £2.00 | £9.99 for 10 |
Seat | £10.99 | |
Wheels + Tyres | £30.00 | £50 for 4x wheels and 2x sets of tyres |
Total | £347.63 |
Limitations
The driver (me) weighs too much! No suspension. Ground clearance is only 4 cm at the lowest point and not suitable for bumpy fields or long unmown grass. Single wheel drive is poor in muddy conditions (otherwise its just fine).
Resources
Twitter Account Charger @BodgeCharger
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