Or I’ll do ya one better than that. Hope this helps.

CrocSee Micro 3 Phase AC Mini Hand Brushless Motor Generator Model Science Experiment Teaching Aid Kit DIY https://www.amazon.com/dp/B0722Z4PX5/ref=cm_sw_r_cp_api_i_04W1ZWK8VSPB7GRYM3Z4

I would say a DC Generator isn't the way to go, because that YaeTek "Generator" is literally just a brushed dc motor.

And a dc motor can be used both as a motor and a generator...

But:

Instead, go for a 3 Phase AC Generator.

It is easier to use, and you dont have to worry about the brushes wearing out

Just hook it up to a 3 Phase to dc converter, and step that up to your needed voltage.

For example:

This 3 phase alternator: https://www.amazon.com/CrocSee-Brushless-Generator-Experiment-Teaching/dp/B0722Z4PX5/ref=d_pd_sbs_sccl_4_1/130-9892245-6840064?pd_rd_w=mSqqg&content-id=amzn1.sym.d8274306-8eaa-4da3-9175-aca6400f9aa9&pf_rd_p=d8274306-8eaa-4da3-9175-aca6400f9aa9&pf_rd_r=710TZGA36KBQ0PDGEH86&pd_rd_wg=1kc8P&pd_rd_r=3098b755-e5e5-4d2a-862f-34f74c6fac54&pd_rd_i=B0722Z4PX5&psc=1

And this micro hydro generator to get the boost circuitry from: https://www.amazon.com/Beduan-Turbine-Generator-Hydroelectric-Changeing/dp/B07PHR4K9Z/ref=sr_1_1_sspa?crid=NM4FJMKKG3BN&keywords=beduan+micro+water+turbine+generator+hydroelectric&qid=1667442614&qu=eyJxc2MiOiIwLjAwIiwicXNhIjoiMC4wMCIsInFzcCI6IjAuMDAifQ%3D%3D&sprefix=beduan+micro%2Caps%2C135&sr=8-1-spons&psc=1

(You can get the 12v version instead, but I prefer 5v)

These 3 phase generators are easier to use, and require much less force to turn; however, i would recommend using gears to increase the rpm of the generator, or rewinding it so it gives out more amps (there are diagrams on how to rewind on google)

This has also been a long term project I have kept in mind; I was waiting until I got my 3D Printer to really get serious about it, since I needed to make custom parts and mounts that I couldn't do without a 3d printer.

Let me know if you have any other questions!