I said I was building a new car a few days ago,

I said I was building a new car a few days ago, what I wasn’t showing was the full adjustable chassis suspension that i was developing and building.

I call it the RS-01 OpenRC Fully Adjustable Racing Chassis.

RS-01 Open RC F1 Adjustable Suspension Racing Chassis.

Front suspension video:

Rear suspension video:

Body and shock demonstration:

Introducing the RS-01 3d printed chassis designed for the Open RC F1 Remote Control Car.

I’ve named this chassis the RS-01. The “RS” stands for Riverside Speedway. The Riverside Speedway was a historic track, located on the border of Moreno Valley and Riverside, California, that hosted all of the greats from Carol Shelby to Mario Andretti. It even hosted many Formula 1 races. I grew up in Moreno Valley, less than a mile away hearing the sounds of engines filling the air, so I hold that track and it’s historic history as part of my heritage. As a homage to this great track I’ve named my chassis after it.

About Me: I’m a car guy who learned Computer Aided Design (CAD) 5 days ago (since I posted this)… This is the first design that I’ve made. No lie!

GOALS:

The RS-01 Chassis is designed to turn the Open RC F1 into a competition RC race car. This car is a 3d printed version of competition RC cars like the Tamiya F104 Pro and 3Racing FGX F1—cars that cost around $600.

It features tunable front pushrods, adjustable rear suspension with an anti roll dampener. The front suspension translates the movement through rocker arms that then compress the shocks. The rear suspension moves independently of the main body. It is basically a Live Axle with a Panhard Bar. It not only compresses, but can also move torsionally, so if one wheel hits a rock, only that wheel will move up.

Modular Design

I designed this chassis to be modular. You can run 3d printed wheels, or actual plastic wheels from the store—just by changing the axles. Different motor mounts will also be easily swapped in by printing out a different rear chassis which has the correct holes for that particular setup. I did this so that people can choose which type of car that they want to build. If you just want to experience the Open F1 RC car in its full 3d printed form, then you can. Those 3d parts bolt right up! Now you can have a printed 3d printed suspension to help you corner faster and hopefully avoid crashes caused by having no suspension, BUT if you are focused on building the fastest remote control car that you can have, with the most powerful motor and stickiest rubber tires that you can find—cars that can run 80 mph, then this chassis will also work for you. In its race form it is designed to use Tamiya F104 rear motor mounts and rear axle. With these additions, the sky is the limit. Go to the track and show people how fast a 3d printed car can go!

Front Suspension:

I chose a pushrod double wishbone suspension over a typical Macpherson strut suspension for two reasons: (1) I wanted the shocks to fit within the Formula F1 Body, and (2) believability—a pushrod suspension is the exact type of suspension that real Formula 1 cars use, so it was fitting.

Rear Suspension:

Rear suspension needs to move not only laterally, but also torsionally for greater control. The shock is mounted inside the car and attaches to a mount on the rear chassis. The damper controls the roll of the live axle. It will prevent the rear wheels from reacting too fast, so you can adjust the rear of the car for your particular settings and environments. Lower control arms allow the hinging action ,and the upper control arms are nearby with springs attached to keep everything level. You can swap out these damper springs for further adjustment of the car. All these parts work together to create a suspension setup that allows you to adjust the stiffness of the rear suspension by adjusting the shock settings, damper springs and even how strong the damper works through use of particular thicker fluids.

Body:

The body has minimal modifications. The Front, Lid, engine cover and bottom chassis are the only replacement body parts. All other body parts, and files can be found in the original Open RC F1 files. The Front was changed to allow room for the double wishbone suspension, the Lid was changed to allow space for the front shocks. The engine cover had to be modified to allow movement for the rear suspension. With the shocks being exposed you have the benefit of seeing how they work as well as quick access to adjust the shocks settings.

Servo:

To be a real F1 RC car, you have to use rear and powerful servos. However, with the size restrictions of RC car bodies you need to use a low profile servo. The servo that I am using is a low profile servo from Hitech.

Hitec RCD 31077S HS-77BB Low Profile BB ServoSpeed
(4.8V/6.0V): 0.18/0.14 sec @ 60 degree
Torque oz./in. (4.8V/6.0V): 61/76, Torque kg./cm. (4.8V/6.0V): 4.4/5.5

It has great specs and even better—a great price. It retails for $25, so it is the perfect servo to use in the Open F1 Rc car because it is powerful, and is designed for use in F1 projects like this. Servo mounts are included.

Battery:

The battery is mounted lengthwise in the car for better weight distribution by keeping the center mass in the center of the car. The battery cage can fit any battery up to the size of the Turing nano-tech Shorty 4200mah 2S2P Hardcore Lipo Pack (96x46.4x25mm).

Shocks:

The RS-01 chassis uses 55mm shocks. Any shocks can work. The front shocks were modified to use longer 110mm shafts with carbon fiber tubes acting as shaft covers. The spring rate is currently 19 lbs/ft, but the great thing is that you can use any 55mm shock and spring rate that you want—it’s all tunable.

Screws and taps:

To keep weight low, I used metric taps to screw the bolts into the plastic. M3-1.0 screw taps, and bolts.

I’m very proud of this chassis that I designed and built. I will be developing this suspension setup until it reaches all of its design goals. I will also make different body types so you can change your Open F1 RC cars looks.

Look for updates:

Because I designed it and 3d printed it from scratch in the last 5 days, there are many updates that will be done. Mainly to the front suspension. The rear suspension works great, but there will be updates to files. I hope to have all the updates completed in the next 2 weeks.

My guess is you are showing us because it works ! Nice work

Thanks. It’s a show and tell. I wanted to show it.

Fantastic, really enjoyed the detailed write up.

Wow, @brett_turnage That is just so awesome! Super cool!!!

Looks awesome! Did you gather intel from how its done on Traxxas offroad cars which utilize a similar setup?

Have you look into the possibility of utilizing the 3d-printed shocks from the OpenRC truggy?

That’s really impressive! What does it cost for all the parts? Is there still room for electronics?

@Tom_Nardi thanks! I had written this entire detailed write up for why I designed it this particular way and going through all of the features, but then I had to chop it way down for Pinshape. I wanted to post it here with the entire features. Thanks for reading it–I know it’s long, but very informative.

@Daniel_Noree thanks a lot Daniel and everyone else for that matter! I just learned CAD, 6 days ago now, so I’m hoping to refine certain aspects so the files are cleaner, but yah. I couldn’t let the Truggy guys have all of the cool chassis engineering–plus I’d love to see your 3D printed car be at the track racing the best F1 RC cars in the industry.

@brett_turnage What CAD software did you use? So far I’ve only been using sketchup and it seems pretty limited when it comes to editing curved parts like the body. If you are interested in collaborating on further refinements to this project, I’m game. I think we both have some excellent ideas to contribute to the cause!

@Jesper_Henriksen thank you Jesper. I actually studied the Tamiya F104 Pro and the 3racing FGX, but to be honest most of my knowledge and reading came from my personal background building racing cars. The Pan style rear suspension that this chassis and other F1 Rc cars is actually nothing more than a Live Axle (a suspension where there is a differential and a solid rear axle move independently of the chassis. It can be setup in a 4 or 3 link setup, depending on whether a torque arm is used. A live axle suspension that is equipped with a Panhard bar: a bar that is mounted on one side to the chassis/frame and the other side to the axle with a swinging arm to control side to side movement and torsional control over bumps. A Panhard bar is one of the two setups [Watts-link being the other] that can be used in a live axle into a suspension setup that has great turning and handling capability. I have installed two Panhard bar setups on my cars so, once I understood what it was, I was able to figure out what my design required. The Rc version may perhaps be different looking or the different parts may be in different areas, but they are still all there: upper and lower read control arms, axle, and Panhard bar. The front suspension was just a typical pushrod suspension setup that many cars including current F1 cars. So yes I studied a little bit, but I think a vast majority of the reading why I designed it the way I did came from my background in cars.

For shocks–it’s all modular. As long as they are 55mm you can choose any shocks that you like. I left certian areas open where people could choose which parts they want and some parts like the rear lower control arms which mine are metal may be replaced by someone with a 3D printed version.

@Ryan_Hoagland thanks Ryan. First let me answers the room question. I designed it in CAD with mockup a of the battery that Daniel used because most people got that battery. I made sure to lay everything out correctly and designed around that battery so that it would all fit. With the low profile servo that I used and the battery the esc can be placed on either side of the battery box and the recieved can be placed on the opposing side. For this setup wire management is key, so zip ties and making sure the esc to motor wires are tied down.

Cost right now is around $60 with the new servo and shocks. I’m going to have to do a detailed build sheet, but I’m going to refine the front suspension so the price may decrease, but I would expect it to be around $60.

@Ryan_Hoagland Blender man! Best program ever! But after you download it go to http://cgcookie.com pay $24 to access the detailed courses and you can build detailed parts like this. All I did was finish one course of meshes and then I was able to build everything in my chassis in 3 days! I have AutoCAD, and I wast trying to learn it, but the videos no Blender made it quick and easy to understand. Cannot recommend Blender and CGCookie enough. This chassis build is proof of how awesome they are and 3 days!

Great Work!!! Will def be building one of these!