I am about to build a laser engraver. I have done a lot of research, and I only found ones which are built from old DVD drives. It is good, but they can engrave only about 4X4 cm surface.
I want to build a machine which can engrave about approx. 20X20 cm surface. I would use it to engrave wood, plastic, glass, and cut paper stencils.
I want to use nema 17 stepper motors, since I have a 3D printer and I have some spare parts (1 motor, pulleys, belt etc)
The mechanics will be fine, I will use drawer rails (the no-wobbling type) and a wood. The small parts can be 3D printed.
The problem is the electronics and the coding. I thought I will use an arduino UNO and a CNC shield. What do you suggest? This one.
Questions:
Which laser module should I buy? How many mW?
How to wire this thing up?
How to do the coding?
Important: I am trying to keep the costs of this project as low as I can.
That shield should be fine for controlling the stepper motors - PROVIDED that the motors don'e require more than about 1.2 amps per coil. If you are not sure post a link to the motor datasheet.
I know nothing about lasers or how you control them. I wonder if you need a high-power mosfet such as would be part of a shield for a 3D printer. I don't see anything like that on the shield in your link. Maybe search for Reprap shield
I don't think you are going to find anyone who will write you an essay about wiring everything up or who will write a complete program for you. However you will not be the first person making a project like this so there is probably a lot of advice on the internet.
That motor requires 1.7 amps and that is almost certain to overload the A4988 drivers in the shield you linked to. It may be possible to use Pololu DRV8833 DRV8825 drivers in the same shield, but they would be close to their limit as well.
I have not seen links to shields that can carry several higher-power stepper drivers but you could, of course, connect individual drivers without using a shield.
I'm not sure what you mean by this
I will find another forum here to specify the laser parameters.
if you are thinking of starting another Thread on this Forum then I suggest you don't. It is much easier to help if all the info about a project is in one place.
...R
EDIT 22 Jul 2020 - very late I realised that I gave the wrong ID number for the stepper driver. It should be DRV8825. The other driver is for DC motors. Sorry for any confusion.
The A4988 drivers can drive motors up to 2 amps. It will drive those motors fine. I have drivin 1.5 amp. motors and they work fine. Like anything, they can probably drive 3 amp max.
pfaltys:
The A4988 drivers can drive motors up to 2 amps. It will drive those motors fine. I have drivin 1.5 amp. motors and they work fine. Like anything, they can probably drive 3 amp max.
The experience of others on this Forum is that the practical max for an A4988 is about 1.6 or maybe 1.7 amps unless there is a heat sink and a cooling fan. 3 amps is definitely out of the question - just read the Allegro A4988 datasheet.
It is never a good idea to operate electronic equipment close to its limits. My rule-of-thumb is to choose a driver with at least 50% excess capability. Your use of a nominally 2 amp driver with a 1.5 amp motor is not too far away from that.
Your best with the taller heat-sinks aligned to the air flow super glued to the driver and a suitable fan with a good CFM will be just over 1.8 amps on those drivers. (case usage here)
Use of the sticky tape for the heat sinks can be fraught with issues such as movement of the heat sink causing shorts.
Anything above that will almost certainly reduce the life of the driver.
I have a small collection of dead ones if you want them as proof.
Good to know! I wil have to keep that in mind for the future. I forgot to add that I always have heat sinks on my drivers. I will upgrade the heat sinks right away. My guess is that my motors were not geting full power.
