How to Make 3D Printing RC Car

I’m a student from Taiwan, currently studying in kaoshiung senior high school.

I am a RC car player. I like to design components to upgrade or fix my rc car, but I think it is time to design full rc car by myself. After I design all the rc car and assemble it, I find there is a limited range to control rc car. But I want to control car no matter where I am. So I mount the raspberry pi, 4g lte hat and apm2.8 flight controller on rc car to achieve unlimited range control.

Let’s get started!

To make this rc car you need to prepare some tools and components.

Tools:

• Hex Wrench
• Drilling machine
• taps
• Grinder
• Hammer
• Center punch
• Pliers
• Screwdriver
• Iron
• LASER cutter
• 3D printer

Material

• ABS filament
• 3mm,5mm PMMA board
• 3mm 6061 aluminum alloy board

Additional purchased parts (can't 3D print)

• M3 screws(The screw length you need is in the picture above)
• M3 nuts
• M4*10 screws
• HSP 02024 (differential)
• HSP 106004 (Shock absorbers)
• HSP motor gear 0.6M 21T+64T
• HSP 06022 87mm (transmission shaft)
• HSP 02033
• HSP 03015 bevel gear
• HSP 02100 12MMcombiner
• Tie rod
• Servo tie rod
• 12mm hex wheel adapter
• Servo arm
• Bearing(683ZZ、6700ZZ、693ZZ、MR105ZZ)
• 550 motor or brushless motor
• Motor speed controller
• Servo motor

Additional purchased parts for 4G lte rc car

• Raspberry pi 3b/3b+/4b
• Pi camara
• USB cable
• sim7600x 4g lte cat-1 hat
• Fly controller(apm2.8 or pixhawk)
• 5v 3010 fan

NOTE:

1. If you buy screws according to the picture above, the number of screws will exceed the actual number needed, but the number seems to be appropriate after considering repairs or other uses.
2. Because my rc car design some of screws need to be cut before ㄓyou mount it.

I used Fusion 360 to design my rc car. I divided rc car into three parts to design. First part is front wheel, second part is back wheel, third part is chassis. Because most of parts while used 3D printer to make, I try to decrease dangling area of the part to reduce support material. So all parts are very easy to 3d print .I attached full .step and .f3z in the end of the Instruction, if you want to change some design you can download all files and change whatever you want.

I used ABS filament to print all the components, because ABS plastic is a good material to resist impact. And this is also a common material for 3D printing.

There are some notes if you want to print ABS.

1. Be careful when you print ABS because hot bed’s and nozzle’s temperature is very high, to prevent injury don’t touch the printer bed.
2. ABS is very sensitive to environmental temperature change so if you can put your printers in closed environment.
3. ABS is very easy to absorb water so when you don’t use abs filament put it in the dry box.
4. To prevent warping you need to open Brim or Raft function and turn down fans when you print ABS

ABS print configuration

• Bed temperature: 100
• Nuzzle temperature: 245
• Nuzzle: 0.4mm
• Layer height: 0.2 mm
• Infill: 20%
• Wall thickness: 1.6mm

To make the chassis we need to cut the 6061 aluminum board but I don't have expensive cnc machine or fiber laser cutting machine even worse I don't have wire saw machine that can cut alloy board so I choose alternative way to cut.

If you can use wire saw machine that will make you more easy deal with alloy board, if you can use cnc or fiber laser cutting machine congratulate you can just jump over this step because you just need to put .dxf file in the computer and get beautiful finished product.

If you like me have limited tools don't be sad because I will teach you how to cut the alloy board use drill. First you need to download chassis and second floor board .dxf files and print or laser cut them if you don't have laser cutting machine just use printer. After that fix the mold on the alloy board with your fixture and outline them, if you use paper just stick paper on alloy board.

Prepare the hammer, centerpunch and drill table now you can start second step. You need to draw offset line first, and offset distance depends on drill diameter, if your drill diameter is X mm you need to offset X/2+0.2 mm because you need some allowance which can be sanded off later Than you can take hammer and centerpunch to mark the drill location like pictures above.

Next you need to put alloy board on drilling machine and drill on the marks you make. After that you can easy use wire saw cut the board. And use rasp or grinder to remove extra material and burr, now you can start assemble.

Before starting this step, you must first prepare the parts that will be used in this part.

3D printing parts

• left upper arm*1
• left lower arm*1
• right upper arm*1
• right lower arm*1
• left c-hub*1
• right c-hub*1
• steering block*2
• mount block*1
• shock tower holder*1
• steering arm*1 (include part1 and part2)

Laser cutting parts

• linkage block*1

Metal cutting parts

• shock tower*1

Additional purchased parts

• HSP 106004 (Shock absorbers) *2
• 12mm hex wheel adapter *2
• Servo tie rod *1
• Tie rod *2
• 12mm hex wheel adapter *2
• Servo arm
• 683zz*2
• 693zz*2

Screws and Nuts

• M3*18
• M3*20
• M3*25
• M3*35
• M3*40
• M3 nuts
• M3 lock nuts
• M4*10

NOTE:

1. When you assemble, you can open the design drawings attached below, so that you will know how to assemble.
2. Some of screws may be too long to assemble so you need to cut to the right length.
3. If you purchase the tie rod using the link I attached above, you may notice that it isn't long enough to mount. If you meet this situation you can lengthen the connecting rod using m3 fully threaded rods.
4. If you find that some screw are hard to get through of hole you can use 3mm drill to clean the remainder in the hole.
5. When you mount bearing you can use rubber hammer to hammer bearing to make interference fit. But don't use metal hammer to hammer bearing, you may broke bearing. And if you notice that you barely can't mount bearing, you can use heat air gun to uniform heating 3d printing part that will let you easy to mount. But be careful using heat air gun if you let 3D printing part overheat , you will let them deformation.
6. If you want to screw don't overtight the screw, just use appropriate torque or you will broke 3d printing part.
7. When designing this part, some parts inside have undergone some modifications, such as c-hub, so please use the latest version of stl files attached below when printing parts.
8. In the latest version, I designed a bumper to protect the front wheel from impact, but the installation of the bumper must ensure that the screw length is long enough.

Front wheel steering system

Bumper

Before starting this step, you must first prepare the parts that will be used in this part.

3D printing part

• left upper arm*1
• left lower arm*1
• right upper arm*1
• right lower arm*1
• Motor mounting holder*1
• c-hub*2
• shock tower holder*1
• shock tower holder block*1 (this part is for double shock absorber)
• shock tower block*4 (this part is for double shock absorber)
• differential up box*1
• differential down box*1

Laser cutting parts

• shock tower*1(this part is for double shock absorber)(You need to cut 5mm thick pmma board)

Metal cutting parts

• shock tower*1

Additional purchased part

• HSP 02024 (differential) *1
• HSP 106004 (Shock absorbers) *2 or *4
• HSP motor gear 0.6M 21T+64T *1
• HSP 06022 87mm (transmission shaft) *2
• HSP 02033 *2
• HSP 03015 bevel gear *1
• HSP 02100 12MMcombiner *2
• 12mm hex wheel adapter *2
• MR105ZZ
• 6700ZZ

Screws and Nuts

• M3*10
• M3*18
• M3*25
• M3*35
• M3*55
• M3*60
• M3 lock nuts
• M4*10

NOTE:

1. When you assemble, you can open the design drawings attached below, so that you will know how to assemble.
2. Some of screws may be too long to assemble so you need to cut to the right length.
3. If you find that some screw are hard to get through of hole you can use 3mm drill to clean the remainder in the hole.
4. When you mount bearing you can use rubber hammer to hammer bearing to make interference fit. But don't use metal hammer to hammer bearing, you may broke bearing. And if you notice that you barely can't mount bearing, you can use heat air gun to uniform heating 3d printing part that will let you easy to mount. But be careful using heat air gun if you let 3D printing part overheat , you will let them deformation.
5. If you want to screw don't overtight the screw, just use appropriate torque or you will broke 3d printing part.
6. Back wheel driving system have two different design. Type 1 mounted two shock absorber, Type 2 mounted four shock absorber. You can choose what kind of type you want. If you want to mount more hardware on rc car like raspberry pi, LIDAR you can choose type two.
7. When you mount motor gear (21T) and big gear (64T) ensure the gap between two gear isn't too big or too small, if you gear gap is to small you will let motor overload and overheat even you will broke your motor and ESC and your battery will drain very fast. If your gear gap is to big, gear will be broken and can't output power correctly.
8. Because motor gear and big gear expose outside you don't need to add lubricant between motor gear and big gear if you add lubricant you will let dust and little rock attach on gears.
9. You need to add some lubricant in differential box that can protect damage between HSP 03015 bevel gear and differential and decrease annoy noise.

TYBE 1

TYBE 2

Before starting this step, you must first prepare the parts that will be used in this part.

3D printing part

• servo motor holder*1
• car shell part 1*1
• car shell part 2*1
• second floor support*1

Metal cutting parts

• second floor
• chassis

Screws and Nuts

• M3*35
• M3*55
• M3*60
• M3 lock nuts
• M4*10

NOTE:

1. When you assemble, you can open the design drawings attached below, so that you will know how to assemble.
2. Some of screws may be too long to assemble so you need to cut to the right length.
3. If you find that some screw are hard to get through of hole you can use 3mm drill to clean the remainder in the hole.
4. If you want to screw don't overtight the screw, just use appropriate torque or you will broke 3d printing part.
5. If you think aluminum is difficult to cut you can just use wood or plastic board.
6. When combining two car shells, you can use super glue or AB glue to fix it, and you can use screws to lock it before it is fully glued
7. You can mount 4010 fan on car shell that fan can help cool down 550 motor.

Before the remote control car can run, you must first install electronic equipment on it, such as receiver, servo, motor, ESC, remote control, battery and so on. But the price of these things can range from a few hundred dollars to a few thousand dollars, depending on your requirements for speed and handling. The following is my electronic equipment configuration, suitable for beginners, very easy to remote control, and very cheap.

Beginner configuration

• 550 motor
• MG995 servo
• SANWA mx-6 radio and receiver
• 5200 li-po 2s battery
• ESC

If you think you need higher speeds you can also choose brushless motors and ESCs with higher amps, you can also choose servos with higher torque or waterproof electronics, so that your rc car can drive in muddy water, You can even add a gyroscope to make your rc car less prone to shaking.

Next, we will start to connect these electronic devices. The reference diagram will be provided above for you to connect.

Tools and Consumables

• Iron
• Heat air gun
• Solder
• Heat shrink tube
• Solder paste
• XT-60

NOTE:

1. Be careful with your hands to prevent hot soldering irons and heat air guns from burning your hands.
2. Try to use a large wattage soldering iron, which can make the temperature increase faster and easier to solder
3. If you find that the solder is not easy to stick to the soldering iron or wires, it is recommended that you clean the tip of the soldering iron and add flux when soldering
4. After soldering, use heat shrink tube to wrap the bare part of the wire, which can be waterproof, but before that, please clean up the remaining flux, otherwise it may corrode the wire.

Photo source

https://www.google.com.tw/url?sa=i&url=https%3A%2F%2Fwww.elprocus.com%2Felectronic-speed-control-esc-working-applications%2F&psig=AOvVaw1OJ5t5SmCXVaazAvuFq8e8&ust=1687741543669000&source=images&cd=vfe&ved=0CBMQjhxqFwoTCPigtKud3f8CFQAAAAAdAAAAABAE

Assemble the remote control car and connect all the circuits and you can start playing.But there are still some things you must pay attention to when you play.

NOTE:

1. You must pay attention to whether there are cars or people in the area where you play, drive your rc car carefully, high-speed rc car hitting people may have serious consequences.
2. Be careful with your battery, please don't drain your battery too much, it may cause an explosion or even the risk of not being able to charge, to make sure you can know that the battery is about to run out you can buy a tester, if your voltage drops to the minimum value it will Make a beep to get you to change the battery. (Tester)
3. If you just finished driving the rc car, please do not touch the motor or ESC or it may cause burns.
4. You can 3D print a few more easily damaged parts, which can be replaced immediately when you need repairs.

You can print more of the following parts

Vulnerable parts

• Front wheel left upper arm
• Front wheel left lower arm
• Front wheel right upper arm
• Front wheel right lower arm
• Steering block

The main purpose of this car is to experience the fun of remote control cars, but it is obvious that there are still many shortcomings of this car that have not been improved, such as only rear wheel drive, heavy weight, short remote control distance and so on. I will continue to update this remote control car in the future, for example, use fusion360 generative design to make the structure of the remote control car lighter. In the future, I will write an article about how to connect the remote control car to the 4G network to achieve remote control. Hope you guys enjoy this tutorial.

Thanks for reading