Project: movable model of a grinding machine


I'm working on a movable model of a grinding machine. (The company I'm worikng for, builds grinding machines and I want one of our machine types as a model)
At the moment I'm reworking all the part in CAD so I can print them. But the model should be movable with motors and I plan to do this with Arduino. But I have absolutly no idea how you program an Arduino but I will try to learn it.
First of all I need the right hardware so I find the right place for it before I finish engineering the model.

So here is my question: Which arduino board is as small as possible and can do the job.
The board have to controll these parts:

  • 3 steppermotors
  • 1 normal motor
  • 3 switchs for the zero-point of the sterppermotors
  • 2 switch to check if the doors are closed (so the programm won't start if the doors are open)
  • 2 Buttons to start a program each, which is saved on the board.

Thank you
Greeting Sepa1818

You'll need a minimum of two pins per stepper, probably two for the motor so that's fifteen, plus two for the serial port for debugging. A Nano can satisfy that need and is small.

Whether it's fast enough depends on how quickly you need to turn the steppers.

Whether it has enough memory depends on how complex the two 'programs' are.

The Teensy range are all faster and have more memory than the Nano.

Don't forget that the steppers and motor will need driver boards.

You can control stepper motors with a small control board which make things easier (depending how small you need it as three of these and an Arduino would soon start to take up a lot of space).
see: How to Control Stepper Motor with DRV8825 Driver & Arduino

Probably not really what you are looking for but if you have a look at GRBL on the ESP32 it is really impressive and you could have your model actually running from gcode (assuming it is a cnc type grinder). You can buy one with all the hardware ready to go or install it on your own esp32 and go from there.
BTW-You can install GRBL on an Arduino but then you would require a PC to send the gcode to it.

I would suggest you just get yourself an Arduino, and a couple of drv8825 boards asap and have a play, you will then have a much better idea how it all works and what you want to do for your model. You could even try GRBL on it and see if it looks like something you could use. (this is what I did and next thing I was building myself a CNC router)

Thanks for your informations. Is there a difference between the arduino nano and the arduino nano every?

@wildbill: How exactly do you count 15 pins?
I would count:

  • 3 steppermotors with 2-4 pins each (2 with the version alanesq wrote)
  • 1 normal motor 2 pins
  • 5 switchs with 2 pins each
  • 2 Buttons with 2 pins each
    That would be 22 Pins

@alanesq: Thanks for the website. My model shouldn't realy grind. The purpose is to look like a real one and that it can move and pretend to grind. But I like the idea with the stepper driver, cause I have some experience with 3D printer and for these I have some stepper driver at home.

Nano every is a bit faster and has a bit more memory. I have never used one.

I was counting digital input pins. Obviously a button will have two wires going to it, but one of them will be power or ground which can be shared, the other will be a digital pin that counts towards the total I came up with.

1 per switch or button.

Only require one pin for doors.

You can get away with one pin for homing all motors.

You can control stepper motors with a small control board.....

The arduino is The control board.
DRIVER boards regulate the power to the motors.

If you have a axis surface grinder you typically only need one axis at a time.

If you know you will never run two steppers at a time you can use one pin for direction for all stepper motors and individual pins for stepping

on pin for the spindle motor
2 per stepper driver (6 total)
1 pin for all door
1 pin for all home switches

that leaves you with a full SPI bus or I2C bus for a display like a DRO

if your company offers a controller, it would seem that you could simulate all the features of that controller.

also, there is a mini-mega that has over 50 GPIO's available.

Thanks for the Information. I have orderd the Nano every and will try to run it. Also I will see if everything will fit in the modelsize electrical cabinet.

@dave-in-nj: With the first program I want to simulate grinding a plate and with the secound program I want to simulate truning the grinding wheel on a single point diamond tool. For the truning I will need all three steppermotors at the same time if I want to simulate the movemet as realistic as possible.

6 pins steppers
1 pin spindle
1 pin doors
1 pin homing (minimalist requirements)
2 pins (individual homing)

3 pins optional encoder menu
4 pins SPI bus display

You can use the ADC pins as inputs

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