r/3dprintedcarparts

Been working on this project for the last month or so. Nearing completion

A fun part that my company produced on our SLM machine for a customer. It is printed in AlSi10Mg aluminum. The flanges need to be surfaced before it ships, but the part turned out beautiful.

H2c printer, left nozzle does the tpu and right does the HTPA-cf

If you've ever tried to find a replacement boot for an old steering rack, a custom shifter setup, or a weird CV joint on a project car, you know the struggle. You either buy a "universal" one that fits like a trash bag, or you spend hours on eBay looking for a NOS part that's already dry-rotted.

I got tired of it, so I wrote this OpenSCAD script to generate custom TPU bellows for exactly this reason.

Link: https://makerworld.com/en/models/2763439-parametric-tpu-bellows-custom-dust-boots-covers#profileId-3068396

Why this is useful for car parts:

1. Rounded Wave Profile: Defaults to a smooth, rounded wave profile. These last way longer in TPU because they eliminate the stress concentrations found in sharp zig-zags. (Zig-zag style is still available if you prefer it).
2. Mixed Shape Geometry: You can mix and match circular and rectangular shapes. Need a rectangular bottom cuff with a rectangular bellow and a round top cuff for a shifter boot? It handles the transition math automatically.
3. Decoupled Cuff Sizing: You can set the top and bottom cuff sizes independently of the bellows opening. This lets you create perfect clamping surfaces even if the hardware you're connecting to is much larger than the boot itself.
4. Reinforced Cuffs & Transition Zones: Includes dedicated straight clamping sections at both ends for hose clamps or zip ties. You can set independent transition heights to bridge any difference in size or shape between your mounting points and the flexible bellows folds.
5. No supports needed: The folds are optimized with 45-degree angles so it prints clean in TPU without internal or external supports.
6. Split Mode: Includes a toggle to add a slit down the side so you can wrap it around a rod or cable that's already installed without taking your whole assembly apart.

Printing Tips for Car Use:

• Filament: Use 95A TPU for most things. If it's near the engine, keep in mind TPU's melting temp, but for suspension, steering, and interior, it's solid.
• Walls: I recommend turning up walls to 100 to make it grease-tight and make sure the flex areas are at least 1.5mm thick
• Layer Height: 0.2mm works great for the 45-degree overhangs.

Hope this helps someone get their project back on the road!

A buddy of mine who runs a tuning shop asked me to design and print a housing for a winch relay. He’ll do the final wiring and installation, I handled the enclosure.
300A relay, 250A fuse, Amphenol connectors carrying the main winch current, and a side cutout for the control signal connector. Printed TPU gasket for sealing, brass heat-set inserts for the lid.
Printed in ASA-CF. Honeycomb texture matches my brand logo — form and function.
Still a work in progress on his end — will post the final install when it’s done.

As someone here might remember, a couple of months back I made a post about my 15mm 3D printed spring spacers I put on the front suspension of my Audi A4 B9 (TPU 95A, 100% concentric infill).
Since so many people asked me to post an update after a while, here it is:
first pic is the day I installed it, second one is last week as I was replacing a ball joint that had been clunking for the past 6 months.
The "after" picture of the car has been taken today.

As you can see, it's holding up perfectly fine, no sign of deformation and the added ground clearance is still all there.
I have driven the car approx 4k km in all conditions, be it fast, fully loaded and in fairly hot climate (a couple of times all at the same time lol), and I couldn't notice any particular squeaks or weird behavior coming from the suspension.

Link to the original post:
LINK

This is an angle regulator. It sits on a metal tube at the blue internal face. The 3 flat flaces around sets 3 angle positions.

I'm not sure if this is ok or if the metal will tear the printed layers open.

I thought of something like a threaded insert, but without the thread, is this a thing?

Welcoming new ideas on this one.

When I had bought my Honda ruckus, someone else had butchered up the battery mount. I went with a smaller and stronger new battery with the GY6 swap so made this to prevent the battery from sliding around. And yes, I know I put the clip .5” too far forward. No I probably won’t fix it lol

I printed the test fit in ABS but wondering what I should use for good long term durability. Pa612? Pps?

Someone mentioned it would be nice to have a parametric automotive bumpstop, so I decided to just build a generator for it in OpenSCAD. It turned out pretty versatile, so I thought I'd share it! It supports everything from simple cylinders and cones to ribbed "progressive" style bumpers that get stiffer as they compress.

Link: https://makerworld.com/en/models/2792707-tpu-customized-parameterized-universal-bumpstop#profileId-3105603

Key Features:

• Fully Parametric: Adjust diameters, height, and taper.
• Flexible Mounting: You can toggle between a "Shaft" mode (simple through-hole) or a "Bolt" mode (recessed counterbore from the top).
• Adjustable Seat Height: You can set exactly how much TPU is between the mounting surface and the bolt head to prevent it from tearing out.
• Progressive Ribbing: You can add any number of ribs/segments and control the "bulge" for that classic rubber bumper look.
• Optional Base Plate: Adds an integrated plate if you need a wider footprint for mounting.

I've been printing these in 95A TPU with about 100 walls and 100% infill and they feel incredibly stout.

Safety Note: As always, be careful using printed parts for critical mechanical or automotive applications. These are great for prototyping or specific off-road needs, but use your best judgment!

Would love to know if there are any other features you'd like to see added.

My other projects:

• Parametric TPU Bellows: Custom Dust Boots & Covers
• Customizable Parameterized TPU Gaskets / O-rings
• Fully Customizable Parameterized TPU Bushing

Hi sorry this is my first post on reddit, sorry if it’s the wrong sub!

I’ve recently tried to remove the Touch-Adapter Voice V2 from my Volkswagen polo but when I remove it, it leaves this large hole in the dash. I’ve tried finding STL files to fill it but have had no luck.

Has anyone else had this problem or designed/found a pre made STL file to fill the hole?

For reference I have a 3d printer but am not good at designing things, just usually find pre made stl files. Thanks!

Hey everyone,

Huge update! I updated my OpenSCAD bumpstop generator with some actual physics! Instead of guessing "30% infill" and hoping it's squishy enough, you now specify the target stiffness in kg/mm for 3 separate zones. It automatically creates the right thickness grid infill in the customizer to your specified rates separately in the top middle and bottom. It also vents out the bottom through the infill grid so the TPU won't blow out under compression.

Link: https://makerworld.com/en/models/2792707-parametric-tpu-bumpstop-stiffness-based-kg-mm#profileId-3105603

How it works: The script is calibrated for TPU 95A. It uses a Young's Modulus calculation (frustum-area aware) to figure out exactly how much internal grid is needed to achieve your target spring rate. It even accounts for the stiffness of the solid outer shell!

Latest Updates:

• Stiffness-Based Input: Set kg/mm for the Top, Middle, and Bottom zones.
• Automatic Grid Spacing: The script now "intelligently" sizes the grid. It scales the spacing based on the part diameter and checks against your nozzle size (0.4mm default) to ensure the internal lines are actually printable.
• Cutaway View: Added a "show_cross_section" toggle so you can see the internal grid structure and mounting geometry in OpenSCAD.
• Progressive Rates: You can easily design a bumpstop that starts at 10kg/mm at the top and ramps up to 100kg/mm at the base.

Standard Features:

• Fully Parametric: Adjust diameters, height, taper, and top rounding.
• Flexible Mounting: Toggle between a "Shaft" mode (simple through-hole) or a "Bolt" mode (recessed counterbore).

I've been printing these in 95A TPU. Because the grid is part of the STL, you just set your slicer to 100% infill and 999 walls and let the printed geometry do the work. The OpenSCAD console will tell you exactly what density and spacing it chose for your settings.

Safety Note: Be careful with automotive/high-load applications. These are great for tuning and prototyping, but always test thoroughly!

Let me know what you think!

I picked up a free wind fairing that was a few inches too short for my vehicle so I designed and printed these extensions and riveted them on with some 1/8” aluminum rivets. After a couple of days having these installed, they’ve both started warping in the same manner.

They are 2mm thick with 3mm tall ribs all around the sides and the one in the middle. Printed in ABS-GF on my Creality K1. 260 nozzle temp and 100 bed temp with a 40-50 degree chamber temp. 0.6 nozzle and 0.3mm layer height. They didn’t warp while printing and came off perfectly flat so I imagine it’s a design issue rather than a printing issue. They also warped the opposite way than I would typically expect from an issue with the printer.

I hope drying the filament more isn’t the answer, but it might be. Would more ribs on the back, thicker material, or different rivet placement help? I appreciate any and all thoughts.

So this is originally a android screen car facia, I bought a 10 inch to 7 inch adapter so I can mount a double din. I have a problem I couldn’t know before I mounted it. The original radio is lot bigger from outside but in the inside it’s small and mounted on a 45 degree angle, there is a plastic that blocks me to mount it at a 45 degree angle so I couldn’t use the 10 in to 7 in adapter. What can I do here? How can I design this pretty easily? I have an access to 3D makerpro lynx scanner but don’t know how to really use it. Any tips appreciated, it must not be 3d printed I’m open to everything

PS: The car is a 2009 Subaru Justy

This week on *insert Bilbo meme* "Why shouldn't I make dumb stuff with my printer?"

We've got a novelty number plate, because I got tired of looking at the empty space 😅

The plate is 275x120mm, with Aus bolt hole spacing of 210mm apart & M6, and made in such a way as to allow easy font/colour changes to suit whatever you wanna do - do read the description

Enjoy 🤝

Novelty Number Plate (Australian Spacing) - Free 3D Print Model - MakerWorld