Creality Ender 3 Stock Factory Vref

README.md

Creality3D v1.1.2 stock vref values

A4988 Drivers
Vref set to ~90% of stepper rated current
Rs = 0.1ohm

X = 0,58v (0,725A)
Y = 0,58v (0,725A)
Z = 0,58v (0,725A)
E = 0,72v (0,900A)

Stepper Motor datasheets

Naming: [JK][S]HS[L]-[100][4]

JK: Manufacturer (jkongmotor) S: Size (42mm) HS: Hybrid Stepper L: Length (34/40mm) 100: Rated current 1.00 4: Number of wires

• X, Y, Z: 42x34 1.8deg 0.84A 4xwires jk42hs34-0844 yal8-23

• E: 42x40 1.8deg 1.0A 4xwires jk42hs40-1004a-02f

• http://www.jkongmotor.com/Product/42HS-NEMA17-2Phase-Stepper-Motor-1-8%C2%B0.html

• https://jkongmotor.en.made-in-china.com/product/pvdJZFXCiRks/China-Jk42hs40-1704-NEMA-17-3D-Printer-Stepper-Motor-42mm-Reprap-Motor.html

References

• https://reprap.org/wiki/Pololu_stepper_driver_board
• https://reprap.org/wiki/A4988_vs_DRV8825_Chinese_Stepper_Driver_Boards

@not-crazyramen the currents listed on the blueprint are max currrent. To find the RMS divide the max current by 1.414. I run my Sprite extruder driven by TMC2209 UART at 600ma. Hope that helps.

Yeah it does. Thanks! Do you know if that's the industry standard for "rated current?"

Not sure exactly how industry determines that.

The manufacturer decides what temperature the motor can tolerate continuously without degradation of the insulation on the motor's windings. They then determine how much current in 100% duty cycle stepping operation will raise the windings to that temperature.

That's the rated current.

Note that my explanation here is simplified a little.

@not-crazyramen the currents listed on the blueprint are max currrent. To find the RMS divide the max current by 1.414. I run my Sprite extruder driven by TMC2209 UART at 600ma. Hope that helps.

Yeah it does. Thanks! Do you know if that's the industry standard for "rated current?"

Not sure exactly how industry determines that.

The manufacturer decides what temperature the motor can tolerate continuously without degradation of the insulation on the motor's windings. They then determine how much current in 100% duty cycle stepping operation will raise the windings to that temperature.

That's the rated current.

Note that my explanation here is simplified a little.

On 3D printers it is usually set 80% of the rated current. Hope that helps.

I can't speak to "usually". It's often as high as 90%, and it can be set much lower to save a little power if you aren't running a race printer. Feel free to adjust it downward until your printer starts losing steps, then back up until the step loss disappears.

Then pop a note into the control board compartment to remind yourself of that adjustment in case you ever get the Need for Speed and want to adjust it higher again.

@MaxMishchenko any chance you can reach out to your contact and see if they have details for the BJ42D15-26v12?

@MaxMishchenko any chance you can reach out to your contact and see if they have details for the BJ42D15-26v12?

I've specs Here for both BJ42D15-26V12 and BJ42D15-26V19 (This is the same spec as the BJ42D15-26V02 hence drawing ID matching)

@not-crazyramen the currents listed on the blueprint are max currrent. To find the RMS divide the max current by 1.414. I run my Sprite extruder driven by TMC2209 UART at 600ma. Hope that helps.

Hi pal. It´s correct divide by 1.414. Is not multiplicate by 0,707 for RMS Value?

@not-crazyramen the currents listed on the blueprint are max currrent. To find the RMS divide the max current by 1.414. I run my Sprite extruder driven by TMC2209 UART at 600ma. Hope that helps.

Hi pal. It´s correct divide by 1.414. Is not multiplicate by 0,707 for RMS Value?

It’s the same thing…
1A/1.414=0.707A
1A*0.707=0.707A

Hi. I think you're wrong pal. I remember the electronic classroom in the first year and say0.707. i find this:

How to calculate RMS value of current?

Then, the RMS voltage (VRMS) of a sinusoidal waveform is determined by multiplying the peak voltage value by 0.7071, which is equal to one divided by the square root of two (1 / √2)

Dividing something with 1.414 is the same as multiplying something with 0.707. I’m not smart enough to see what the problem is. Hopefully some one else can help you.