Marlin Step Motor Speed at Microstepping

[veysel_olgun]

Hello,

I am using MKS Robin Nano v3.0 card

I am controlling Step Motor (Nema 17 0.47 Nm)

My Step motor driver card is TMC2209

Steps Per unit for Z axis is 25600

I am making autofocus operation on digital microscope project. Most of the time in autofocus operation, motor movement taking much more time.

My autofocus operation is based on hill climb. For example, I am taking about 20-25 frames to complete autofocus operation and it is taking 2-4 seconds to complete(Motor movement + frame grabbing)

I asked a question on here(Marlin forum) Step Motor Speed at Microstepping .

What i want to know is how fast i can complete 1 micrometer movement with this configuration ?

For example is it possible to complete 1 micrometer movement operation 0.02 sec or lower ? and If i do this movement 25 times, than will my total time be 0.5 sec (or lower) ?

[kolaha]

read motor datasheet. look for minimal Step impulse duration. then you can convert it into movement commando, like G1 Z0.000001 F6000000

[Railroader]

Please post a link to the stepper datasheet. NEMA.... only tells abot the mounting holes.
Steps per unit..... What is that "unit"?
Schematics never hurt as stepper perfonce rely on driver voltage and coil current.

[veysel_olgun]

Thank you for your replies

Step motor model: 17HS8401S

Step Angle: 1.8 degree
Rated Current : 1.7 A
Phase Resistance (ohm) : 1.8
Phase Inductance (mH) : 3.2
Holding Torque (N.cm Min): 48

This is link of 17HS8401S Step Motor : 17HS8401, 17HS8401 Datasheet, 17HS8401 PDF - MotionKing

If I disable motor's wire then time is same. I plug out wires of motors then run G1 Z0.001 F5000, time is same 0.1 seconds. So I think that motor's attribute is not issue for marlin software (maybe i am wrong)

[veysel_olgun]

@kolaha

like G1 Z0.000001 F6000000

Thank you, I increased F value but no luck, still taking 0.1 sec for 1 micrometer

[kolaha]

did you changed max speed option?

Set Max Feedrate

show your current settings (M503)

[veysel_olgun]

Yes, I changed the some values, here the simple python code screenshot

It complete 10 micrometers (1 by 1) in 1.06 sec, 1 micrometer is equal to about 0.1 sec. I also added F900000 to command but it is still same

[kolaha]

Z acceleration is 100, it may take time to go to maximal speed of 90000000.

and try G0 command too.

if shortest possible step pulse is 10µs, then 1mm takes 25600 * 0.01*2 = 512ms = 0.512s

[veysel_olgun]

Hi thank you for your time

I tried below setup but it is still same

Do you think 0.1 seconds for 1 micrometer is good or normal ? What do you think for this situation do you have any advice ?

[kolaha]

may be TMC2209 need some adjusting

[veysel_olgun]

Do you mean on Marlin software configuration ?

[kolaha]

i have not read tmc2209 datasheet
and you say no motor name to look its datasheet

[veysel_olgun]

Okay thank you