Your tumbler. Your car. One perfect fit.
Enter a few measurements and get a custom 3D-printable cup holder adapter built for your exact setup.
How It Works
No CAD experience needed. No searching for your car or tumbler model.
- 1
Measure
Measure your car's cup holder and your tumbler with a tape measure or calipers.
- 2
Preview
Watch your custom adapter take shape in a live 3D preview as you type.
- 3
Test Fit
Print a free 3mm sample of just the base and the receiver to confirm the fit.
- 4
Purchase
Happy with the fit? Unlock the full adapter for a one-time $4.99.
- 5
Print
Download your STL, 3MF, and print guide, then print the real thing.
See it before you print it
As you enter measurements, a live 3D preview shows exactly how your adapter will look — including the narrow base, the smooth transition, and the handle cutout if your tumbler has one.
Try the GeneratorWhy Custom Fit?
Pre-made adapters assume your car and your tumbler match someone else's. CustomFit3D builds the part around your own measurements instead.
No model lookups
You never need to find your exact car trim or tumbler brand in a database.
Built for unusual shapes
Tapered cup holders, wide-body tumblers, and handled tumblers are all supported natively.
Verified before you commit
Free 3mm fit tests let you confirm the fit physically before paying for the full part.
Free 3mm Fit Test
Before you spend filament on the full adapter, print a free 3mm-tall sample of the vehicle base and the tumbler receiver. It uses the exact same clearances as your final part, so a good fit here means a good fit on the real thing.
- Uses almost no filament or print time
- Built from the same measurements and clearances as your final adapter
- Tell us Too Tight / Perfect / Too Loose and we adjust the clearance for you
Built for real tumbler shapes
Tumblers are rarely a simple cylinder. The generator models the actual shape — not an approximation.
Straight tumblers
A consistent diameter from base to insertion depth.
Tapered tumblers
Gradually widening or narrowing walls.
Wide-body tumblers
A narrow base that smoothly widens into a wide upper body.
Handled tumblers
An open slot in the adapter wall so the handle passes through cleanly.
Designed for 3D printing
Every generated model is validated before it reaches you: watertight mesh, sane wall thickness, and a base that can actually pass through your cup holder's opening.
- Watertight, manifold mesh — checked automatically before download
- Minimum wall thickness enforced for printability
- Rigid-insertion checked: the base is built to actually fit through your cup holder opening
Simple, one-time pricing
No subscriptions. No per-model marketplace fees.
Always free
$0.00
- Live 3D preview
- 3mm vehicle fit test
- 3mm tumbler fit test
Full custom adapter
$4.99
Included with your purchase
- STL file
- 3MF file
- Print guide (PDF)
- 3 free regenerations
Frequently asked questions
No. You only enter measurements — the geometry is generated automatically.
Ready to build your adapter?
It takes a few minutes to measure, preview, and test fit — before you spend a cent.
Create My Adapter