OpenRC F1

The OpenRC F1 project caught my eye already long time ago. Since the day I saw this, I wanted to make one myself. It seemed unbelievable to me, that you could just print your own RC car and drive it around... The day I got my 3D printer, it was my objective to print this thing and make it work.

Parts

Finding the electronics actually is the hardest part of this project. There were 2 main sources for the parts: eBay and my local modeling store.

Mechanical parts

The mechanical parts consist of the following:

1. Bearings
2. Tires
3. Bolts and nuts

The quantity and exact nature of these parts can be found in the files available here.

The mechanical parts were difficult to find on eBay, so I went to the local modeling store to find these.

I also want to give a rough price tag:

Bearings: you need 6 bearings to build this car. I bought mine for about €2 a piece, so the total price for the bearings is €12.
Tires: this was a little painful for me.. I wanted to get good grip so printing the tires was out of the picture. I bought Tamiya R104 tires for a total of €40...
Bolts and nuts: about €6

The total price for all the mechanical parts comes down to about €58. This does not include the filament for printing.

Electronic parts

The electronic parts consist of the following:

1. Battery (and also a charger if you don't have one)
2. Transmitter and receiver
3. ESC
4. Motor
5. Servo

For the battery, I went with a 2S LiPo one. It's a tight fit but I could make it work. I found a battery on eBay for €30. I also bought a charger for €10.
The transmitter and receiver, I bought second hand on eBay for €40. The ESC (€25), motor (€8) and servo (€2), I bought new on eBay. I went for a brushed motor to cut down the costs.
So in total, the electronic parts costed me about €85 (€75 without charger).

Summary

So in total, to construct this car, you would pay around €143. I used PLA to print all the parts. I bought a black and an orange roll, which added €40 to the total price tag. Not all the filament is used however. It is possible to cut down these costs. Firstly, you could print the bearings instead of buying them. You could consider this if you are not planning to drive the car very much, but I think if you actually want to drive this thing a lot, it is not worth it to cheap out on the bearings. Secondly, you could print the tires. As they were very expensive in comparison to the rest of the parts, this would be a great reduction of the price tag. However I did not find a way to print good tires cheaply. You would need a flexible filament (NinjaTek for example), and these filaments are expensive as well (expect to pay about €40 for one roll of 0.5 kg).

Design

Previous model

The first openRC model I printed was grey. This already looks awesome, but I wanted to give it an even cooler look by printing the bottom in black, and the body parts in lava orange,  like the mcLaren F1 cars in 2017.

My first OpenRC model

Current model

Right now, my printer is printing parts for the new model. It is already looking good!

First parts of new OpenRC F1 (1)

Printer, working on the OpenRC F1 car

First parts of new OpenRC F1 (2)

First parts of new OpenRC F1 (3)

Work in progress

Mechanics

In the original OpenRC F1 project, the rear axle is stiff. This setup results in a poor road handling. To solve this problem, I wanted to design a differential. Sadly, designing a differential is not an easy task.. So I checked the internet to search for someone who did exactly that. And that someone exists!
You can get the differential here.

Addition of differential to rear axle

After installing the electric motor and the rear axle assembly, I searched for an optimal position to fit the battery, ESC and receiver. The picture below shows what I eventually ended up with.

Positioning of electronics inside the car (1)

Positioning of electronics inside the car (2)

The only thing that still needs to be installed is the servo. I will do this after the front wheel assembly is printed.