This time let me start with the most famous song from Bob Dylan:
"How many times must a man re-design
Before you call it a "must have"?
How many roads must a chassis withstand
Before you upload it online?
The answer, my friend, is MyRCCar KIDS
The answer is MyRCCar KIDS"
- - Simpler and stronger chassis with configurable wheelbase from 250mm to 300mm in steps of 5mm
- - Configurable caster per axle in different positions
- - With this new design, you will only need some allen or screwdrivers to change these features, instead of having to print and change some parts
- - Most of the edges has been softened so it is less lesive for kids in the worse scenarios. The same way, the gearing and central transmission has been covered to avoid kids contact
New 3d printable 1/10 RC car drifting / on-road / touring / rally chassis redesigned with exclusive features as adjustable wheelbase or rotating axles to adjust caster.
Instead of having to re-print different parts you will just need to un-screw a few parts and screw them together again in a different position.
The idea behind this is to be able to use different wheelbase bodies without having to reprint parts or a new chassis. The car is mainly divided in two big parts, the front and the rear, which can be screwed one to each other in different positions.
This allow you to choose your prefered wheelbase from 250 to 300mm in steps of 5mm, which shoud be fine for most of on-road cars.
The best thing about this feature is you don't need to disassemble any electronics or mechanic parts, as they are fixed to the front or the rear part but not both.
Another great thing about this is you don't have to adjust the central transmission length for each wheelbase as it is also designed "elongable" to acomplish the "adjustable wheelbase" feature.
The same way than with wheelbase, the idea is to be able to choose from different caster angles for your Front and Rear axles without having to re-print parts to acomplish it.
I have tryed to re-imagine the suspension system and now all those parts (arms, arm holders, butterfly and butterfly holder) are linked to some new parts which I call F/R Diff Box Sides!.
These sides rotates over the real diff. box and are conected to each other with the butterfly and the front lower arm holder.
When correctly assembled the whole front or rear axle (including the transmission, steering links etc) can rotate a few degrees to the front or the rear. Once you have chosen your desired caster for each axle, you can use one screw on each side of the axle to fix the caster position.
These screws go through the diff box sides using different holes and screws in different holes in the main F/R diff boxes. Choosing the right hole can be kind of a game itself :S
- - Direct Motor Pinion / Crown or geared main transmission
- - Low profile
- - Light weight
- - Number of parts and screws reduced compared to other models
- - Support free*, most of the parts don't need supports
- - Great steering angle (near 45º)
- - Great and quite protected space for battery (140-190mm long, 50mm wide, 25mm high)
- - Holes for what is coming
What is included?
This publication is about the chassis. You can see various bodies over the chassis as a demonstration of its capabilities. The same way, you can see 3D printed wheels and shocks which are not included. The blue and red Tesla Roadster 2020 are 260mm and 275mm wheelbase versions in PetG and TPU respectively from the great Roadster design from Shadowcraft Designs
- - Main Chassis, Steering, Suspension, Transmission, Body Holders and Bumper parts are included
- - "MRCC_KIDS_TESTPART" to test your printer and selected slicing process before printing big parts
- - "MRCC_KIDS_template_80mm_holes" Simple template "tool" to help marking holes in the body
- - "Fake Axles/Pins" to be 3D printed while you can source the metal ones
- - Motor pinion for the standard "geared" configuration. 2 versions of a 14T Mod1 Motor pinion, for 3.17mm and 5mm motor shafts
- - Simple bad-english writen assembly instructions attached, indicating screw type and size for each step, naming and identificating parts
As PLA has been the cheapest material during a while I have designed and printed my designs with it. I think if it works with PLA, it should work even better with other more "industrial" materials as ABS or PETg. Personally, I never took control completely of ABS printing, and I'm actually experimenting with PETg. What I mean is that sometimes can be better a good print with a bad (PLA) material than a bad print with a good (and more expensive) material. So a very good inter-layer adhesion will help making the mechanical behavour of your parts more omnidirectional. Can you do that with PLA?¿? If you do, remember not expose the chassis in the sun and heat for hours and monitor and control temp of your motor and electronics if you don't want surprises.
ODE TO TPU:
The same way I think PLA is enough for most of the parts, I also use TPU as a "luxe" for some smaller parts which make sense if printed in soft materials. TPU is not ideal for tires, but is what I tried for my 3d printed wheels with PLA rims. Apart from wheels, it will be necessary for a good connection with car body or for hit-related parts, but also as a "seal" or holder in the 3d printed shocks. You will find it mostly in all my projects. I recently finished a 750g spool and I'm waiting for the next one ;)
I know many people are using bowden machines which would not allow to easily print flexible materials, but maybe you can do it slower and changing a few params so... maybe you could give a try to a little spool of TPU... if there is no way with your machine maybe you can re-sell it second hand...
Specific ON-ROAD INFO:
This version of the KIDS Chassis is for building an On-Road / Touring / Drifting 1/10 3D printed RC Car.
- - It will use short CVDs so the total axle width will be less than 190-200mm
- - Includes a Universal Body Holding System, adjustable in position and height, with flexible parts (TPU) which will avoid most of the breaks
- - Features a flexible Front Bumper which will help with front collisions absorbing part of the impact
- - Front suspension arms can be 3d printed solid in TPU and will make the chassis much stronger against impacts in the front wheels
- - Default Total Gearing Reduction Ratio of 11,6
- - Adjustable Camber through Upper Arm length
- - Adjustable Toe-In Toe-Out of front wheels through Steering Pin length
- - Different Butterflies to fit your needs
This chassis should be compatible with many sourced On-Road, Drifting or Touring Body Shells, if they are wider than 190-200mm and have a wheelbase between 250 and 300mm.
The same way, it is compatible with some of MyRCCar Bodies:
- - Mustang Eleanor Body. A design by Rockser3D. Rigid body composed by various big, medium and detail parts. High-poly design for FDM printing. You can use the Universal Holding System for this one and a 280mm wheelbase
- - Oldie Pickup Two Styles. Maybe you prefer this old pickup design also from Rockser3D
- - Typical Pickup Body 2. (Coming soon) A new smoothed revisitation of the TPB, with optional Crawler Front Bumper, Single Cab, Flat Bed and more!
- - Tesla Model-S Body (Coming). Use the chassis sides provided for KIDS in the Model-S publication instead of the standard ones and set your KIDS chassis wheelbase to 295mm. You won't need the Universal Body Holding System but you can use it instead
- - Tesla Roadster 2020 Mini. (Coming, from Shadowcraft Designs) A minimal body shell which uses the Universal Body Holders, Butterfly_S in the front axle with 55mm shocks and 260mm wheelbase.
- - Tesla Roadster 2020 TPU Version. (Coming, mod from Shadowcraft Designs)The most ressistant one... Thicker TPU shell with PLA reinforcements to keep shape and 275mm wheelbase
As you can see, there are a few already out there, but more will come if you help me in this MyRCCar Adventure!!!
SOURCED PARTS NEEDED:
First and don't forget, the electronics
- Motor and ESC (25€)
- Servo (7€)
- Battery and charger (20€)
- Radio and Reciever (18€)
- 2X HSP 02024 diff. (10€)(Example)
- 4X On-road Short CVD(10€) (Example)
- 14X bearings 5x10x4 (8€) (Example)
- 8X bearings 10x15x4 (5€) (Example)
- 3mm Piano Wire (2€)
- Lots of M3 screws (4€)
- Double-Side Tape (3€)
- Velcro strap (1€)
Printable but better if sourced
- 4X On-Road Wheels (6€) (Example)
- 4X 55-70mm Shocks (4€) (Example)
The prices of parts are ovbiously a guidance so you can make numbers easier. You could buy a rc car kit which includes maybe the CVDs and wheels you want and part of the electronics (always talking about 1/10 scale) but if you plan to buy all those parts...
That's around 43€ to 69€ for chassis parts and 70€ for electronics! Or maybe you can take most of parts from other RC projects you don't actually attend...
As you can see, this chassis is initially planned for building an On-road car, that could mean a drifting one, a touring or rally build. But respecting 1/10 scale, most of the car bodies are under 200mm, many of them around 180mm wide, so if you want the wheels to stay under the body you will need SHORT on-road CVDs. I know HSP 102015 and 122015, but those are a little long if you want your axle wide to be less than 200mm. Anyway, the necessary parts (Lower/Upper Arms, SteeringBlocks,C-Hubs) will be provided to use those HSP CVDs.
The CVDs I'm using are the Mission-D ones from HobbyKing, but I saw other similar ones in aliexpress related to some on-road car, something like RS4?¿? which I think must be the same length. If you find some ones you think are the same but they are not for a few mm or less... I can help you modifying lower/upper arms to the desired length.