Rise of the Teenage Programmer ???

Sorry Madahhlia, below is (hopefully) the non geek version

Windows, Mac, Android, stock standard Linux are all non real time operating systems which mean that the processor is constantly jumping (multitasking) between many different things.
For "normal" use, i.e. browsing the web, compiling a spread sheet and things like that, this multitasking (which takes time to "service" and "jump" between different applications/programs) is perceived as a delay.
However when one is using a computer to control a servo motor (which is one that needs a certain sequence of pulses at a predetermined rate) the multitasking causes the operating system to leave that application every so often and go do other things.
Depending on how fast the processor is, how many other applications are running at the same time and the speed one wants from the servo motor, when it leaves the application controlling the servo, the servo stops, then when the operating system returns, it starts again.
The nett result is a jerky or spurted movement instead of a smooth one.

Hope it makes more sense.

 

You may get a donation of stepper motors if you ask nicely at any Fruit/Gaming machine operator try JPM or Bell Fruit possibly in your area GAMESTEC
We used to use them by the thousand, and many scrapped when moved onto video, just ask for old reels from fruit machines (it was cheaper to chuck the three reels into a scrap pile than pay the time of an engineer to change the middle reel)

I would have asked for you but having shoved one up the CEO's When I resigned, do not think I would have much joy

Just a thought

Jack McH