Engineers in petroleum and tech fields run side hustles alongside their main careers. The ones covered here can nearly double a monthly salary through a mix of hands-on and online side gigs.
Start Freelance 3D Printing
| Side Hustle | Ease of Entry | Earning Potential | Flexibility | Average Hourly Rate |
|---|---|---|---|---|
| 3D Printing | Easy-Medium | High | High | $40.00–$80.00 |
Many engineers treat 3D printing as a hobby that pays. Toy cars, computer stands, keyboard caps, and custom parts are all in steady demand.
Each job needs a design file, which you can create yourself or source from a client brief. Running multiple prints in parallel pushes earnings toward $80.00 an hour, while single-project work sits closer to $40.00.
Offer CAD Design Services
| Side Hustle | Ease of Entry | Earning Potential | Flexibility | Average Hourly Rate |
|---|---|---|---|---|
| CAD Design (3D Model Design) | Hard | Extremely High | Medium | $50.00–$60.00 |
CAD design focuses on modelling rather than physical output. It requires proficiency in tools like SketchUp, which takes a few months to learn well.
Once past the learning curve, steady project work is available on Upwork and similar platforms at up to $60.00 an hour. The higher barrier to entry reduces competition compared to other freelance gigs.
Pick Up Freelance Technical Writing
| Side Hustle | Ease of Entry | Earning Potential | Flexibility | Average Hourly Rate |
|---|---|---|---|---|
| Technical Writing | Easy | Medium-High | High | $50.00–$80.00 |
Technical writing suits engineers well because the work draws directly on existing domain knowledge. Companies post these pieces on blogs or share them with internal teams for reference and problem-solving.
Long-term contracts are common and typically require around 10 extra hours a week. Topics span programming languages, cloud infrastructure, DNS, and similar subjects. Rates for this kind of specialized online work generally run $50.00 to $80.00 an hour.
Consult on Freelance Tech Projects
| Side Hustle | Ease of Entry | Earning Potential | Flexibility | Average Hourly Rate |
|---|---|---|---|---|
| Tech Project Consultant | Medium | Medium | High | $30.00–$40.00 |
Tech project consultants help project leads work through technical decisions and optimize their approach. Engagements are usually short-term, averaging around 20 hours a month.
Entry is credential-dependent, which limits this option to engineers with a demonstrable track record. Higher-end platforms like Toptal, Freelancer, and Guru are the main places to find this type of work.







