Fitment Charts for Model Car Parts Sellers
Measured wheel-and-tire fit charts that small resin and 3D-print sellers attach to listings, so buyers stop asking 'will this fit my kit?'
The problem
Small sellers of aftermarket wheels, tires, and detail parts for 1/24 and 1/25 model car kits get the same fit questions daily. A wrong guess means a return, a refund, and an annoyed hobbyist. Sellers rarely own every kit, so they can't answer with confidence.
Where people complain about it
Look in model car forums, Facebook builder groups, and Reddit hobby communities for threads asking whether a given wheel or part fits a given kit. Also check Etsy and eBay listing Q&A and reviews for fit complaints. Sellers' own listing descriptions often hedge with phrases like 'may require sanding', which hints at the gap.
The idea
Build one-page fitment charts listing which popular kits (for example, Revell and Tamiya releases) a seller's wheels and parts fit, with measured wheel-well and axle details and notes on trimming. Sellers add the chart as a listing image and PDF. Update it as new kits come out.
Solo and small-shop sellers of resin, 3D-printed, or photo-etched model car parts who sell on Etsy, eBay, or their own site and handle their own customer messages.
Charge $75 to $150 per chart covering up to 20 products or kits, plus an optional $10 to $15 per month for updates when new kits are added.
Start for under $100
- Buy digital calipers (about $20) and pick 10 popular 1/24-1/25 kits you can borrow, buy used, or get measurement help for.
- Make a clean one-page chart template in Canva or Google Sheets showing kit, wheel-well width, axle fit, and trimming notes.
- Message 5 to 10 small parts sellers with a free sample chart built around one of their best-selling products.
- Ask builder groups for measurement contributions on kits you don't own, and credit them on the chart.
- Invoice via PayPal or Stripe and deliver the chart as a PNG and PDF within a week.
Landing the first customer
Find an Etsy shop selling 3D-printed or resin wheels with fit questions in reviews or messages, and offer to build one free chart as a trial.
What could go wrong
- Measurements must be accurate. A wrong chart creates the returns it's meant to prevent, so label each entry measured or reported.
- The niche is small, so you may need to expand into other scales or part types before income becomes meaningful.
Verify demand in 15 minutes
Every idea is a hypothesis. Run these searches before you spend a dime.