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I can’t calibrate the number of steps per turn


#1

I am trying to assemble the CNC, I did not find the recommended motors. for this I bought 12V 1:17, a chain with a link of 12.7mm. the number of steps per revolution of an asterisk is 11 * 17 = 187 steps.

When I enter all the parameters in the program settings, the motors will be selected and the program will give an error

When I leave the standard parameters - everything works fine - but instead of one turn of the asterisk - I get 10.7 turns.

Is it possible to adjust the number of steps programmatically, or is it easier to make an additional gearbox?


#2

The encoder has two channels, and the firmware watches for the rising and falling edge of every pulse. That’s part of the reason that the numbers are different. Can you give a link to the motor so we can look for the proper numbers?
In the mean time, you could try using 187 * 10.7 = about 2000 steps to see if that’s close, then adjust that number through trial and error.

[Edit] Welcome to the community, @w_fish !


#3

I bought on aliexpress a year ago - the link is not working.
Here is a link to the same https://www.amazon.ca/31zy-2480-HL-Holzer-Encoding-8000rpm-Torque/dp/B071JDVG4Y + 1:17 gearbox.
chain sprocket 7 teeth printed on a 3D printer.

thanks for the fast support and sorry for my english


#4

I tried to enter different values: 2000 - 2200, and with decimal values and different steps. and increased value of more than 10 000. The result is the same - vibrating motors (as they are driven by AC)
if you return the value of step 8113.73, the motors start to work smoothly - but with an unsuitable number of revolutions for me


#5

The chain you use is 12.7mm, and your sprocket has 7 teeth. There are settings in GroundControl Settings/AdvancedSettings for ‘ChainPitch’ and ‘GearTeeth’ , are those set? That will make some difference, but might not fix everything.

The ‘vibrating motors’ means that the firmware is at least partially at fault. The stock motors have a gear ratio of 289.77:1 . It might be that the 17:1 gear ratio would need some tuning in the PID parameters of the firmware. There is some information here. I’m afraid I won’t be able to help much with that tuning process, though. I don’t have much experience with it.

Your English is very good. My Russian doesn’t go much beyond beyond ‘Я пью чай’ and my Ukrainian is, sadly, none at all. It’s great to have a member from Kiev!


#6

do the motors turn properly when you are doing the motor testing?

David Lang


#7

The chain you use is 12.7mm, and your sprocket has 7 teeth. There are settings in GroundControl Settings/AdvancedSettings for ‘ChainPitch’ and ‘GearTeeth’ , are those set? That will make some difference, but might not fix everything.

Yes, this data was entered - but as I understand it, they affect more on the calculated part of the workpiece

The ‘vibrating motors’ means that the firmware is at least partially at fault. The stock motors have a gear ratio of 289.77:1 . It might be that the 17:1 gear ratio would need some tuning in the PID parameters of the firmware. There is some information here. I’m afraid I won’t be able to help much with that tuning process, though. I don’t have much experience with it.

Thanks, I suspected that the conflict in the firmware - I will try to dig there. if I don’t get it, I’ll have to design a chain reducer.

It’s great to have a member from Kiev!

Thank you! :slight_smile:


#8

%D0%91%D0%B5%D0%B7%20%D0%B8%D0%BC%D0%B5%D0%BD%D0%B8
yes everything works well and smoothly, I just have non-original motors and I need to correct the number of correct number of turns