Hi guys,
I am new to Arduino and quite new to electronics in general, so apologies if the answer to my question is obvious. I am making a dip coating machine for a university project. I am planning to make the casing for the machine from aluminium. I was just wondering how much I need to consider aluminium being an electrical conductor from a safety point of view. The components I am using include Arduino Uno, TB6600 stepper motor driver, Nema 23 stepper motor, membrane keypad, and I2C LCD display. I plan to have the machine run on UK mains power by using a DC power to screw terminal connector (a 12V 3A power supply will be plugged into this adapter but will be kept outside the machine).
I have read that it will be necessary to raise the Uno board at the very least using nylon screws and nuts. Do I need to consider anything else? Eg. jumper wires coming loose and touching the aluminium casing? ...
Please see the attached photo of my initial component layout design.
As long as you don't bring mains power into the box, the safety aspect is not relevant. Aluminum is conductive, so of course you can not allow it to short out any pins or connectors. You can make a ground connection to it, so you don't necessarily need nylon standoffs to separate it from the Arduino ground. I don't have a genuine UNO on my desk right now, but IIRC the mounting holes are insulated anyway.
Of course, your wires should not come loose. It's a given.
If it's part of a larger, mains powered device, you should connect the case to the mains safety ground, along with the safety ground on any mains powered devices that you include.
I would ground it if possible, you will have EMR (Electromagnetic Radiation) from the UNO and probably the motor and driver especially if PWM driven. This probably will not cause problems on your system but would effect other systems nearby.
Thank you all very much for your replies, very helpful!
Mark, I will look into getting a screw terminal shield for the Uno.
Okay, so I should definitely ground the aluminium housing. Now to ask a question which is likely obvious to you guys. How exactly would I go about doing that for the system pictured in my first post? Do I connect the ground wire to the Uno? Or the DC adapter? And how do I ensure the ground wire is adequately secured to the aluminium housing?
For a bit more context, the entire housing for the machine will look something like this (see below image), with all metallic parts in contact.
Don't power your arduino from 12v if you can avoid it. Best is 5V in on the +5V pin. If you need 12V for motors & such, add a little buck converter for the +5V.
