Is AI CAD worth it? A maker's cost-of-time calculation
Put a value on your evenings and the maths is short: a few dollars a month against hours of CAD, or against parts you never made. Break-even, and when it does not pay.
The two costs
Every 3D printed part costs you filament (cents) and time (the real cost). A functional part in desktop CAD takes a competent hobbyist 30 minutes to 3 hours; the same part described to an AI takes 3 to 12 minutes. The question is what your hour is worth and how many parts you make.
The calculation
Take a modest value for an evening hour, say $20, and a modest habit, four parts a month.
| Desktop CAD | AI CAD | |
|---|---|---|
| Time per part (average) | 55 min | 5 min |
| Parts per month | 4 | 4 |
| Hours per month | 3.7 h | 0.3 h |
| Time cost at $20/h | $73 | $7 |
| Software | $0 (hobby licence) | $3.99 (Maker) |
| Monthly cost | **$73** | $11 |
The plan pays for itself on the first part of the month. At Pro ($7.99, 200 credits), the arithmetic is the same with more downloads.
The hidden column: parts you never made
The bigger saving is not on the parts you would have modelled anyway. It is the drawer divider, the cable clip, the replacement foot you did not make because 40 minutes of CAD was not worth a $0.30 part. At five minutes it is. Most people who switch print more, not the same amount faster.
Credits, explained in time
A download costs 10 credits. Maker gives 100 a month (ten designs), Pro gives 200. Generating, previewing and editing cost nothing, and fixing a design after a download re-downloads free. So a credit is spent per finished design, not per iteration, which matches how time is spent: you iterate a lot and finish a few.
When it does not pay
- You model daily in a professional CAD tool for work and already have templates for everything. Your hour of CAD is 15 minutes, and the saving is small.
- Your prints are art: sculpts, figurines, terrain. AI CAD is for engineering shapes.
- You print one thing a year. Try it free, download once, cancel.
When it clearly pays
- You do not know CAD and were going to learn it "some weekend".
- You make enclosures, brackets, organizers, adapters and replacement parts.
- You iterate: the first print is never the last.
- You want to design at the printer, on a phone or a tablet, not at a workstation.
Break-even in one line
If describing a part saves you more than 12 minutes a month, the Maker plan is cheaper than your time. It saves that on the first part.
Prompts to start from
Open one in the builder, change the numbers to yours, and the model renders in seconds. Keep adjusting in the chat before you print.A cable clip for three 5 mm cables that sticks under a desk edge: a 30 x 20 mm base 2 mm thick with three C-shaped clips 0.3 mm smaller than the cables.
A replacement rubber foot for a chair leg: 25 mm outer diameter, 15 mm tall, an 18 mm bore 10 mm deep for the leg with a 0.2 mm press fit, 1 mm chamfer at the base.
Questions
Generating, previewing and editing are free. Maker is $3.99 a month for 100 credits (ten downloads) and Pro is $7.99 for 200. Fixes after a download re-download free. Cancel anytime.
The software is not free if you count your time. At even $20 an hour, four parts a month cost about $73 of CAD time versus about $11 with an AI tool including the plan.
No. Unused credits from a paid month stay on your account until you use them, even if you cancel, and your models stay saved and editable.