Hi all
Im new to this form and absolute noob in circuits
The reason im here is that i got a used surface grinding machine along with other cnc machines from a used machine dealer. This machine is actually japanese made with high precision but it didnt have the control board (dx4b 400 watts ) the board is super costly as this machine is old and okamoto stopped servicing it.so i dismantled the machine and i made all other motors and hydraulic pumps working except z axis. i found out that z axis is controlled by a servo motor of 400 w (not stepper) but the markings are not shown so i dont know the gear reduction also (gear reduction is high because 1 step in the encoder moves z axis by 0.0005 mm (its less than 1 micron) ball screws are good and no backlash was observed as we dialled and confirmed the movement. I want it to be changed to closed loop stepper motor with atduino control i saw a hollow shaft encoder on the back of the motor and a switch to change modes and another encoder to give pulse so is it possible to change the motor and control it using arduino
Please help
Why a closed loop stepper motor? Your stepper can only move in discrete steps and you can count them. You also need to design in a zero position indicator so you can begin the count at a known point. If the encoder is already part of the machine, you will never be able to match a step count and an encoder count.
Paul
I suggest You look for contact with some really good machinists on Youtube.
Some names: Clough42, Keith Rucker Wintage Machinery, Steve Summers.
ALSO, don’t be scared off by a servo motor and encoder, that’s all that an RC servo is inside the box.
You need to understand the commands being received to tell the z-axis where to go, and how to parse them for your purposes.
The gearing is important, as is the depth calibration, but it’s all pretty easy with a decent h-bridge and the right software to combine the encoder, limit/calibration sensor and the servo driver.
Remember to plan your power sources!
Hi paul
Im going to take out the whole thing and install new motor drive and controls im using closed loop stepper because i want high and low rpm and exact location in the event of failure
George
Good luck.
If it was my project - I reckon the original designers had the right ideas.
Smooth, progressive, incremental, infinite control.
Each to their own.
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