This is the build guide for the P9RC.
Join our Facebook group #
Best way to get help is to join our Facebook Group where you can ask your questions and share your realizations.
Important, read this first #
The body portion of this project uses a lot of support. Not much way around this. The P9RC will require 2.3kg of filament of which, around 600g are waisted in support. If you are a fanatic about wasted filament, this project is not for you. If you use Cura, try the Tree Supports, you might get away with less wasted filament. I personally use PrusaSlicer which does not support Tree support.
This is a long and costly project. Take a look at the BOM before you decide to venture in this project.
At this time, there is no Interior for the body. My next project will be to do an interior design. This implies that some body parts may need to be reprinted once the interior files are available.
Bill of Materials #
The BOM is available here
Disclaimer #
This is a fast and heavy RC. It can cause harm if not handle properly. I cannot be held responsible for any injuries that may occur to anyone in the use of this RC.
Versions #
A new version was released on June the 7th 2022. This version include a belt tensioner which resolve the rear gear skipping issue and a fixed front suspension which behaves better. If you downloaded the P9RC before June 7th 2022, please download the new files here. Read the changes file in the documentation folder to know which files have changed.
A huge thank you to Trevor Innes who made this improved version possible.
Fixes #
In this sections, will be listed the available fixes that are not included in the zip archives you may have downloaded.
The belt tensioner that was available for testing will be replaced by a much simpler solution provided by Trevor Innes. I will try to update the package and files in the upcoming weeks. The good news, most of the parts will stay at the current version.
Printer Calibration #
It is imperative that your printer is well calibrated. The bearing should be a press fit and removed just by pushing on it. It should not drop out or require undue force to install in the calibration part. You should calibrate your printer for every roll of filament, even for the same brand and color. If you need help to calibrate your printer see: My Calibration Process using PrusaSlicer. You can also check this great resource: “Teaching Tech 3D Printer Calibration”
Printed parts required in this step
- _calibration.stl
Printing notes #
Refer to the P9RC Printing Notes for suggestions on how to print parts.
Loctite #
All square nuts are susceptible to come undone while driving. To prevent this from happening you may wish to use Loctite.
Front section #
Ball joints #
Printed parts required in this step
- c_2x steering link 68 mm
- c_Wishbone Lower Left MC
- c_Wishbone Lower Right MC
- c_Wishbone Upper Left
- c_Wishbone Upper Right
You can use the Rod Ends that came with the ball joint and 3mm threaded rod and make your own steering links. This way you will be able to adjust them as you wish and they will interfere less with the shock absorber’s spring.
Cut to 53mm length and adjust to roughly 68mm center to center like this
Servo Mount #
Printed parts required
- c_Servo Mount Left
- c_Servo Mount Right
- c_Servo Mount back traverse
- c_Servo mount front traverse
Servo Motor installation #
Lower wishbones and shock absorbers #
Printed parts required in this step
- c_12x Cone
Upper wishbones #
This orientation is new to the 220607 version. It was the other way around in the previous version
Servo link and steering links #
Printed parts required in this step
- c_ServoLink
Here’s a picture with the threaded rod steering link
Knuckles and wheel axles #
Printed parts required in this step
- c_Front Knuckle Left
- c_Front Knuckle Right
- c_4x Front Wheel Spacer
- c_2x Front Wheels Axle
Floor #
Printed parts required in this step
- c_Front Floor
- c_Front Floor Reinforcement
Wheels Installation #
Printed parts required in this step
- c_2x Front Wheel 5 spokes
- c_4x Front Wheel Spacer
Middle section #
Printed parts required in this step
- c_Middle Floor
Middle cover #
Unfortunately, you will not be able to install the switch where it’s located for the 3 wheels. The body connector to the platform you will install will prevent you to action de switch. So for now leave the switch outside threw the RC motor cable cutout. At a later time I will create an add-on box that will house the ESC outside the middle section.
Printed parts required in this step
- c_Middle Cover
Attach Middle section to Front section #
Rear section #
This is where you would typically start if you already have built the 3 Wheels RC and want to reuse the front and middle sections.
If you want to build the new belt tensioner jump to this document.
Center Wheel Gear #
You can optionally use 4 M3-6mm screws to hold the gear assembly together. Thus far I did not put the screws and did not have any issues.
Printed parts required in this step
- p_Center drive shaft
- p_Flange 1
- p_Flange 2
- p_Gear 72T
Center Gear Support #
Use 4x 10-15-4mm bearings and press everything together. Make sure to insert the 300mm GT2 belt before the next step.
Printed parts required in this step
- p_Rear Center gear support Left
- p_Rear Center gear support Right
Drive shafts #
I designed the drive shafts and yokes to be printed flat on the printer bed. This way the small forks that hold the universal joints will last longer.
Start by installing the yokes with a M3-10mm screw. I then install the universal joint on the drive shaft inner part. I then connect the drive shaft to the yoke. I repeat the same process with the Drive shaft outer part with the wheel axle. Do the same on both sides. Use M2-6mm screws to install the universal joints. The joints need to turn freely. Loosen the screws until they turn freely.
Printed parts required in this step
- p_2x Yoke
- p_4x Cubic Universal Joint
- p_2x Rear Drive shaft Inner
- p_2x Rear Drive shaft Outer
- p_2x Rear Wheels Axle
Optionally, you could use the Traxxas 5452 U-Joints instead of the printed ones. If you do so, print the Drive shaft, wheel axles and yokes with the Traxxas in the name.
Center gear installation on the Rear Floor #
It is now crucial that the belt is inserted over the central gear before this step.
Printed parts required in this step
- p_Rear Floor
- p_Rear Floor reinforcement
Motor installation #
Install loosely at first, when all the screws are in place. Push the whole motor assembly away from the central gear to tighten the belt. No need to go crazy.
Printed parts required in this step
- p_Motor Bracket
- p_Motor Bearing Bracket
- p_Pinion gear GT2 20T v3
Make sure the belt rides on the belt tensioner bearing
Make sure that the screws are parallel to make sure the belt tracks properly on the tensioner. You can see that I did not push the motor real far for the system to work well
Install Ball joints in wishbone. #
The wishbone are designed to be used with Traxxas ball joint. I personally use a small vise to push the ball joint inside the wishbone. The vise will push until it is flush. You will need to wiggle the wishbone until the ball is in the middle of the wishbone. You will know it’s perfect when the wishbone moves with limited friction. Do this for both sides.
Printed parts required in this step
- p_Rear Wishbone left
- p_Rear Wishbone right
- p_2x Rear Wishbone Upper
Install Wishbones #
Use the smaller cones on the upper wishbone. Use the larger cones on the lower wishbone.
Printed parts required in this step
- c_12x Cone
- p_4x Small Cones
Install the Shock absorbers #
My shock have a larger hole a the top side. I need a washer. Maybe you don’t.
Install wheels #
Start by installing the 10-15-4mm bearings in the knuckles. Then insert the M3 Square nuts. They are a tight fit as I did not want them to move around when inserting the screws. Make sure the nuts are centered with the hole, otherwise the screw won’t thread. Don’t forget to install the Rear Wheel Spacer before you insert the rim/tire.
Printed parts required in this step
- c_4x Wheel Spacer
- p_2x Rear Wheel 5 spokes
Attach to middle section #
You may already have square nuts in the middle floor if you already built the three wheels.
Body #
Door sills and platform connectors #
Printed parts required in this step
- p_Door sill left
- p_Door sill right
- p_Body to Platform connector Left
- p_Body to Platform connector Right
Pillars #
The side screw will be used for the door lock. Leave the screw out around 2mm.
Printed parts required in this step
- p_Pillar left
- p_Pillar right
- p_Pillar top
Front fenders #
You have a choice of Headlight ring that will suit your LED size. Choose between the 3mm or 5mm hole if you want to install a LED
Printed parts required in this step
- p_Front fender left
- p_Front fender right
- p_2x_Headlight ring
- p_2x_Headlight
Front bumper #
Depending on your printer size, you can use the full bumper or the three parts bumper
Printed parts required in this step
- p_Front Bumper Part 1
- p_Front Bumper Part 2
- p_Front Bumper Part 3
- OR p_Front Bumper
- p_Front flasher left choose between 3mm or 5mm led holes
- p_Front flasher right choose between 3mm or 5mm led holes
Rear fenders #
Printed parts required in this step
- p_Rear fender left
- p_Rear fender right
Rear bumper and back light #
You can use two different color for the back light. They also have 3mm holes if you want to add leds
Depending on your printer size, you can use the full bumper or the three parts bumper
Printed parts required in this step
- p_Back lights center
- p_Back lights left flasher
- p_Back lights right flasher
- p_Rear Bumper Part 1
- p_Rear Bumper Part 2
- p_Rear Bumper Part 3
- OR p_Rear Bumper
Windshield frame #
Printed parts required in this step
- p_Windshield frame
Doors #
You have the choice of using full doors or separated in two parts, panel and window frame. I find that printing the window frame flat on the bed yields more strength for these tiny parts. If you use the full door, be patient while removing supports from the window frame skinny parts. Do this for both sides
Printed parts required in this step
- p_2x Door hinge
- p_2x Door handle
- p_Mirror left
- p_Mirror right
- p_Door left panel
- p_Door left Window frame
- OR p_Door left full
- p_Door right panel
- p_Door right Window frame
- OR p_Door right full
Door hinges #
Hood #
Make sure you put the correct parts in the proper order otherwise it won’t work.
Here’s a close up of the 4 bar mechanism
Printed parts required in this step
- p_4x Bar 1
- p_4x Bar 2
- p_4x Bar 3
- p_4x Bar 4
- p_Hood
Note that the right side has an additional part called “Hood up bar” and use two M2-5mm screws. If you only have M2-6, grind 1 mm of the end.
Printed parts required in this step
- p_Hood up bar
Trunk #
The 4 bar mechanism should be installed exactly like the hood. do the same on the other side
Printed parts required in this step
- p_4x Bar 1
- p_4x Bar 2
- p_4x Bar 3
- p_4x Bar 4
- p_Trunk
Printed parts required in this step
- p_Motor vent
Roof #
Printed parts required in this step. I personally glue the window frame to the roof part 1. Otherwise it does not always stay in place.
- p_Roof part1
- p_Roof part2
Body to chassis assembly #
Congratulation, you are ready to drive your new P9RC. Now be careful not to crash it the moment you get it outside! I’m serious! You may even want to practice without the body attached
Support #
If you like my builds, please consider buying me a coffee, it encourages me to continue making quality designs. Click on the coffee cup on the right bottom corner or visit the Show Your Support Page. Thank you, it is truly appreciated!
Thanks #
This body style would not have been possible without this great Fusion 360 tutorial by Giichi Endo.
A special thank you to Paul Viscovich and Michael Rudinsky who helped me with test printing this build.
