Amplifier volume knob setSet of three knobs for small audio amps$10 to $18About 0.9 h, 15 gTry more per plateSeen on Etsy
69Score$8.59per hourFewsellersSpecific products to sell
Pick one of these, not the whole niche. Numbers are our estimates for one item.
Large receiver tuning knobReplacement for a lost tuning dial knob$12 to $22About 1.5 h, 22 gTry more per plateIdea to test
69Score$7.07per hourFewsellersCar radio knob pairPair of knobs for old car stereos$9 to $16About 0.8 h, 9 gTry more per plateIdea to test
69Score$9.30per hourFewsellersTube radio knob setFour matching knobs for a restored radio$14 to $24About 1.4 h, 22 gTry more per plateIdea to test
69Score$8.90per hourFewsellersA typical product here: Amplifier volume knob set
Where each $14.00 sale goes
Filament, power, your time $4.06Marketplace fees $1.78Left from this sale $8.16
One sale ties up the printer for about 0.95 hours. $8.16 ÷ 0.95 h = $8.59 per print hour.
At the typical product's mid price, if it sells. Shipping not included.
Why it can work
- Used originals are scarce and listed for real money
- Tiny parts with very low filament cost
- One parametric file can cover many shaft and diameter sizes
Why it might fail
- Layer lines show on a visible cosmetic part
- Each exact model sells only a few units
- Generic vintage-style knobs are cheap and ready made
Be aware before you sell
Files for specific radios are scattered and most licences were not checked, so measure and model your own. Say 'fits Marantz' rather than copying logos, and leave brand marks off the knob face. Etsy asks for your own original design, so a licensed file may not qualify.
How to get a file you may sell
- Make your own. Tinkercad is free and enough for simple shapes.
- Buy a commercial licence. Many designers on Cults3D, MyMiniFactory and Etsy sell one. Read what it allows.
- Use open licences. CC0 and CC BY allow selling prints. NC does not. Filter by licence on Printables or MakerWorld and keep a screenshot.
Real 3D printed listings
Found on Etsy in November 2026. Prices may have changed.
Search live listings
More detail
Our take
Owners of old gear will pay well for an exact match, but each model is its own tiny market. It works as a catalogue of many exact-fit knobs built from one parametric file, and it fails if the finish looks printed next to the original metal or spun caps.
How the score adds up
Profit per print hour26/30
Demand15/25
Low competition20/20
Low legal risk15/15
Evidence quality2/10
The score is our estimate from public prices and signals, not sales data. Evidence confidence: low.
Competition
Used-parts sellers on eBay and generic knob brands cover this, while dedicated sellers of printed exact-fit vintage knobs looked rare.
Make it your own
- Solve one specific problem better than generic listings
- Test one original design before making more
- Show a real photo and honest measurements
Where to find 3D files
Use these for research. Check each licence and never assume you may sell a print. Search links show live results.
- Amp knobs (MakerWorld) Licence: not checked
- Vintage radio knobs, set for Elektrit Allegro (STLFinder) Licence: not checked
Demand signals
- An AudioKarma member could not find a replacement Fisher 500 knob set on eBay and looked at having them printed. source
- Studebaker owners discuss printed radio knobs on their club forum. source
- Used original stereo knobs have their own eBay browse page, with single knobs and sets listed at real money. source
Check your own numbersRead the repair and spare parts guide
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