Step Motor rotating too fast

[Arvand Asghari]

Hi Lex, 

Some of my FED3.1 step motors broke so I ordered new ones based on previous notes in the conversations from Adafruit which are 28BYJ-48 1:16. 

However, upon installing them, they are turning way too fast and the do around 360 turn each time. Can you please let me know what is the rotate degree on FED3? and how I can fix mine?

Thanks,

Arvand Asghari, Ph.D.
Postdoctoral Research Scholar
Potthoff’s Laboratory
Neuroscience and Pharmacology Department
Carver College of Medicine
University of Iowa
Iowa City, IA, 52242

Email: Arvand-asgha...@uiowa.edu

[Arvand Asghari]

To add more context, this is how it turns with the FED3 program. 

[Lex Kravitz]

Hi Arvand,

This is confusing because there are multiple versions of the 28BYJ-48 stepper that look identical and have the same product number but have different gear reduction ratios which affects their speed. The 28BYJ-48 stepper that Adafruit sells has a gear reduction ratio of 1:16.  The 28BYJ-48 we use in FED3 has a gear reduction ratio of 1:64, which is the most commonly sold ratio for the 28BYJ-48 BTW, you can find these for ~$3 each on Amazon or on other sites. For example this product: https://www.amazon.com/ELEGOO-28BYJ-48-ULN2003-Stepper-Arduino/dp/B01CP18J4A

So that's what's causing your issue.  If you want to use the Adafruit steppers you could go into the FED3 library and reduce all stepper movements by 4x to account for the gear ratio difference, but I'd recommend just buying the new 1:64 steppers from Amazon and swapping them out!   Best, -Lex

[Arvand Asghari]

Got it, that's what I thought as well. 

Thank you, I will get the ones from Amazon then.

Arvand