Thanks mate! Current plan is to finish up the next gears video about racks, then probably back to the tank. But I may be interupted by ventilator stuff instead, who knows.

Thanks a lot! I think I'll set up a Patreon soon, though my ambition is to keep as much content as possible free, not behind a paywall. I'll add bearing numbers and links to the other parts in the description. Edit: Description should be fixed now, let me know if anything is still missing.

@@antalz I certainly appreciate it. I understand what you mean by keeping it free. I think like you do, but, Patreon is optional. Goos luck and thank you for sharing :)

I can make a video on selecting brushed DC motors and stepper motors. Unfortunately I have little hands-on experience with brushless motors, though I intend to learn in the near future. For number 2, I usually know what force or torque I want to produce, and at what RPM or speed. Note that force = torque / radius for a wheel, and linear speed = omega*radius. Always calculate in meters per second, Newton-meters and radians per second. I then look for a motor that produces roughly the required torque at roughly the required RPM, and I tend to select a motor with slightly higher numbers than I need because I can always PWM it down later. I think this small wall of text raises an important point. There are a bunch of things I consider super basic, that are actually worth doing a video about. I'll add it to my list of video ideas, thanks for the suggestion.

@@antalz I’d be really interested to see the calculations you did for those motors! I’m currently struggling to figure out what torque a motor produces at a certain RPM without knowing stall torque. If I knew stall torque, together with no load speed I could make the standard torque/speed curve but they usually don’t give stall torque sadly. Anyways, thanks for consideration! BLDCs are really not much more complex than brushed motors. You just need an extra controller for them. I highly recommend the channel “Skyentific”. I learned a lot from him. Cheers and good luck!

You're right, the blue part of the axle is 3D printed. It's essentially a "sleeve" that goes around the steel shaft, and it's mostly a friction fit. I just hammered the shaft into the blue sleeve, it's quite a bit of hammering, it's really tight in there. In a way I'm using the steel shaft as a broach to broach a precise hole for itself in the plastic, it works really nicely. In the final product the 2 screws also help to keep the sleeve in place. The gears are module 1.5 16/32 teeth gears from AliExpress: nl.aliexpress.com/item/33006232471.html?spm=a2g0s.9042311.0.0.28ac4c4dxm9Mr7 I chose them mainly because the pinion fits on an 8mm shaft which most motors have in this size range, and the gear fits in a 10mm shaft which works well with drilling holes for M4 bolts. Putting M4 bolts through 8mm shafts feels too weak to me. I don't have a lathe (yet?) to precisely drill holes, so I wanted to use a set that had predrilled shaft holes. These gear of this set also fits inside the tight space at the front of the tank, which will hopefully become clear once that video is done.