3D Printing for RC Cars: Custom Parts and Upgrades

The RC hobby and 3D printing were made for each other. RC vehicles constantly need replacement parts, custom brackets, body mounts, and accessories that are either overpriced from manufacturers or simply do not exist. A 3D printer solves all of these problems for pennies on the dollar.

I started printing RC parts after breaking my third set of stock body posts on my crawler. The OEM replacements cost $8 plus shipping and took a week to arrive. I printed a stronger set in PETG for $0.30 in material and had them installed the same evening. That was the moment I realized every RC hobbyist needs a 3D printer.

What Can You Print for RC Cars?

The list is practically endless, but here are the categories where 3D printing adds the most value:

Structural and Functional Parts

• Body mounts and posts
• Shock towers and shock mounts
• Bumpers and skid plates
• Battery trays and hold-downs
• Servo mounts
• Electronics mounts (ESC, receiver trays)
• Fan ducts for motor cooling
• Wheelie bars
• Wing mounts

Cosmetic and Scale Parts

• Scale accessories (jerry cans, tool boxes, coolers, antennas)
• Body panels and fenders
• Interior details (roll cages, dashboard, seats)
• Light buckets and lens holders
• Driver figures
• Mud flaps and rock sliders

Tools and Accessories

• Camber gauges
• Ride height tools
• Setup boards
• Pit organization (shock stand, part trays)
• Transport and storage solutions

Choosing the Right Material

Material selection is critical for RC parts because they take real abuse — impacts, vibrations, heat from motors, and UV exposure outdoors.

PLA: For Non-Impact Parts Only

PLA is rigid but brittle under sudden impact. It shatters rather than flexing. Use PLA only for:

• Scale cosmetic accessories
• Setup tools and jigs
• Parts that will not see impact or stress

Do not use PLA for: Bumpers, body mounts, shock towers, or anything structural on a basher.

PETG: The All-Rounder

PETG is my go-to material for most RC parts. It has good impact resistance, handles moderate heat (up to ~80°C), and is significantly more durable than PLA under the repeated stress that RC parts experience.

Best for: Body mounts, battery trays, electronics mounts, fan ducts, scale accessories.

TPU: For Impact Absorption

TPU (flexible filament) absorbs impacts instead of cracking. It is ideal for:

• Bumpers and bumper skids
• Body mount dampeners
• Tire inserts for foam tires
• Protective covers for electronics

Printing TPU requires slower speeds and usually a direct-drive extruder. Bowden tube setups struggle with flexible filaments.

ASA: For Outdoor UV Resistance

If your RC car lives outdoors or races in direct sunlight, ASA is the best choice. It resists UV degradation where PLA and PETG will become brittle after extended sun exposure. ASA also handles higher temperatures, which matters if your parts are near a hot brushless motor.

Nylon: Maximum Toughness

For parts that need to survive extreme abuse — bash-ready bumpers, heavy-duty shock towers — nylon is the toughest filament available for FDM printing. It is flexible enough to absorb impacts without cracking yet stiff enough to maintain shape under load. However, nylon is harder to print (requires dry storage and high temps) and more expensive.

According to 3D Printing Nerd's RC parts testing, PETG offers the best balance of printability and durability for the average RC hobbyist. Reserve nylon and polycarbonate for competition-level builds where maximum strength is required.

Design Tips for RC Parts

Print Orientation Matters

Layer lines create weak points under stress. Orient your parts so the layer lines run parallel to the primary stress direction, not perpendicular.

Example: A body mount post that takes side impacts should be printed vertically so the layers stack along the post's length. If printed on its side, the layers create shear planes that snap under impact.

Wall Thickness and Infill

For functional RC parts:

| Part Type | Walls | Infill | Pattern | |---|---|---|---| | Structural (shock towers, mounts) | 4-5 | 40-60% | Grid or gyroid | | Semi-structural (battery trays, brackets) | 3-4 | 25-40% | Grid | | Cosmetic (scale accessories) | 2-3 | 10-15% | Any | | Impact-absorbing (bumpers in TPU) | 3-4 | 20-30% | Gyroid |

Gyroid infill provides excellent multi-directional strength and is ideal for parts that experience impacts from unpredictable directions — which describes every part on a basher.

Bolt Holes and Hardware

• Oversize bolt holes by 0.2-0.3mm for clearance
• Use heat-set threaded inserts for strong, reusable threads
• M3 heat-set inserts fit most 1/10 scale RC hardware
• For temporary connections, self-tapping screws work in PETG and nylon

Fitment and Iteration

RC parts need to fit precisely. Print test pieces for critical fitments before committing to a full part. A small test block with mounting holes is faster to print than the entire shock tower and tells you exactly whether your dimensions are correct.

Specific Projects for Popular RC Platforms

Traxxas TRX-4 / TRX-6 (Crawlers)

Crawlers are the best platform for 3D printed parts because they move slowly (low impact forces) and benefit enormously from scale customization.

• Scale roof rack with functional LED light bar mounts
• Snorkel and air intake
• Rock sliders and body armor
• Interior details (dashboard, roll cage, seats)
• Custom bumpers with winch and shackle mounts
• Diff cover protectors

Traxxas Slash / Rustler (Bashers)

Bashers need durable parts. Focus on:

• TPU bumpers that absorb frontal impacts
• Reinforced body mounts (stock mounts snap easily)
• Fan ducts that direct cooling air over the motor and ESC
• Battery retaining straps and hold-downs
• Wheelie bar (print in PETG, not PLA)

Arrma 3S/6S Line (Bashers)

The Arrma Granite, Senton, and Typhon are bash beasts, but they break stuff:

• Reinforced front bumper in TPU or nylon
• Servo guard / protector
• Electronics tray with integrated fan mount
• Wing braces and wing endplates

Drift Cars (MST, Yokomo)

Drift cars are all about aesthetics:

• Body kits and aero parts (front splitter, rear diffuser, side skirts)
• Custom wing profiles
• Wheel spacers for stance adjustment
• Interior details visible through clear bodies
• Transponder mounts for competitive timing

The Thingiverse RC car section has thousands of designs organized by brand and model. Search for your specific chassis to find bolt-on parts.

Printing Tires and Wheel Inserts

One of the more advanced RC printing applications is custom tires and tire inserts.

Tire Inserts

Foam tire inserts control how much the tire deforms under load. Printing custom inserts in TPU with varying infill densities lets you tune tire performance for different surfaces.

• Low infill (10-15%): Soft compound feel, good for high-grip carpet
• Medium infill (20-30%): All-around, good for general bashing
• High infill (40%+): Stiff compound feel, good for high-speed stability

Full Printed Tires

Fully 3D printed tires in TPU work surprisingly well for crawlers where grip and low speed are the priorities. They do not work well for high-speed bashers — the centrifugal force at speed can deform printed tires.

For crawlers, print tires with an aggressive tread pattern in soft TPU (85A shore hardness). They grip rocks and logs better than many commercial rubber crawler tires.

Electronics Integration

3D printing makes custom electronics integration clean and professional:

• Custom receiver boxes — perfectly sized for your specific receiver with cable routing channels
• ESC cooling ducts — route airflow from scoops or fans directly over the ESC
• FPV camera mounts — adjustable-angle mounts for FPV cameras
• GPS module holders — for speed runs and telemetry
• LED light bar housings — with integrated wiring channels and lens holders

According to RC Driver Magazine, 3D printed electronics mounts are becoming standard in competitive RC because they allow precise, custom placement that optimizes weight distribution and center of gravity.

Post-Processing RC Parts

Sanding and Painting

For scale parts, sand with 200-400 grit, prime with filler primer, and paint with spray paint or airbrush. Scale accessories that look realistic add enormous value to a crawler build.

Annealing PETG for Extra Strength

PETG parts can be annealed (heat-treated) at 80-90°C for 1-2 hours to increase crystallinity and improve impact resistance. Be aware that annealing causes slight shrinkage (1-3%), so print oversized if you plan to anneal.

Heat-Set Inserts

For any part that bolts to the chassis, brass heat-set inserts provide strong, reusable threads that will not strip. Use a soldering iron to press them into slightly undersized holes in the printed part.

Finding RC Designs

Search 3DSearch for your specific RC chassis name plus the part you need. The AI search understands RC-specific queries like "TRX-4 roof rack" or "Slash bumper TPU" and returns results from across multiple model repositories.

For custom designs, communities on:

• Printables RC section
• Thingiverse RC groups
• RC Groups forum 3D printing section

Cost Comparison

| Part | OEM Price | 3D Printed Cost | Savings | |---|---|---|---| | Body mount set | $8-15 | $0.30-0.80 | 95%+ | | Front bumper | $12-20 | $0.50-1.50 | 93%+ | | Battery tray | $10-18 | $0.40-1.00 | 94%+ | | Scale accessories (5-piece set) | $15-30 | $1-3 | 90%+ |

The savings add up fast, especially for bashers that break parts regularly. A single session at the local bash spot can break $30-50 worth of parts. Having those parts on hand, printed for pennies, keeps you running instead of waiting for shipments.

Final Thoughts

If you are in the RC hobby and do not have a 3D printer yet, you are spending far more money and time than you need to. The combination of instant replacement parts, custom upgrades, and scale accessories makes a 3D printer the single best tool investment for any RC hobbyist.

Start with simple replacement parts for things that break often on your specific vehicle. Once you see how easy and cheap it is, you will quickly move to custom designs, performance upgrades, and scale builds that make your rig truly one-of-a-kind.