I'd really love to know weather I could DIY something that could provide me fully freezed "stop" position, and fully repeatable movement, while using less power than just a simple stepper motor.
As I mention - I want it to run on batteries - which means that the battery life is not the only important factor here. It also has to be portable, must be easy to handle, light and as compact as possible.
Another important factor I didn't realize before I've tried a basic geared DC motor - friction and balance. While stepper motor will easily handle any spikes of torque, the DC motor will not. I'd need to provide perfectly linear hardware balance to get a stepper-kind of linear output (what I'm not able to).
I was spending my time trying to design something based on DC motors, encoders and selenoid lockers, but I trashed the design because too much things (and money) was getting involved, and the project grew up to a monster size. As for now, I'd rather carry few extra battery packs with me (I can at least use them as powerbanks to charge my phone or camera :) ).
I'll look into DC motors / servos for sure, as I can see the potential, but experimenting with them at my stage of understanding this topic, is a way too pricy :confused:
On topic now: :)
I changed the idea.
I'll make 2 series of parallel 26650's, 5500 mAh. (It will give me ~7.4V, 11Ah)
I'll use 3x 14HS13-0804S (0.8A, 6.8ohms, 5.4V, 1.8Kg-cm) + 3:1 reduction ratio 16:48T pulley (5Kg-cm, I take off 0.4KG as friction caused by reduction)
Maximum load 5KG (I don't expect more than 3.5Kg, but I like to take margins)
Based on my calculations, single batterypack will give me about 3h work
Am I correct with the above?