UV 3D Print Post Cure Station

New here and very much new to the world of electronics. I’ve messed a little with a couple of sensors and LEDs and Servos back in the day on Duemilanove board.

Looking to make a 3D print cooker along the lines of this one here https://forum.formlabs.com/t/a-diy-uv-post-cure-lightbox-you-too-can-make/2732

Here is what I have so far as a component sketch
PrintCooker_05.fzz (92.7 KB)

Main Power Kill toggle
Temperature Setting 40-65C
PreHeat Timer
Exposure Timer
Turn Table Speed
Door open close detection
Start Stop button with status indication
Speaker to beep once the bake is done
LCD display to view settings and time left to bake

Main power

Mega 2560 Controller

Turn Table stepper motor

Temp Probe

Door Switch

Start Stop Button with RGB LED and Momentary Switch

LCD Screen

Using this as wiring info since the website points to something else

Rotary Encoders


2 rolls split up into 4 panels all wiered in parallel

Heating Element

Fan for heating convection

What I need help with at the moment is to look over the sketch make sure I have everything compatible and hooked up correctly (before I buy the components and fry something), as well as help me identify missing parts. I am not sure exactly how and when and what type of transistors to use so if someone could help me with that issue be awesome.
I know that my bread board can be arranged out differently I am doing it so it’s very clear for me (I am a very visual person)

My end goal is to actually get a PCB printed once I breadboard the project to see if it will work.

Thank you in advanced!

You have a number of things missing here, some easy (pull up resistors on your encoders and start stop switch, current limiting resistors on your rgb led) some more difficult (high current switching for your UV LEDs and heater and a motor controller for your fan.) It also looks like your 12 V power supply is too low in current capacity, the UV leds alone want 2 A the fan will want an unknown but non zero amount and the Arduino will want a couple of hundred ma or so and the heater wants an unknown but probably large (as in an additional 800ma or so ) of power at 12V so the original article’s 5A 12V supply is probably more reasonable. For breadboarding a dual 1.5 or 2 amp motor driver would do for your fan and heater, it may be a little small for your LEDs (since it is desirable to not be running at a devices maximum current rating). There are cheapish 6A single channel motor drivers available from Ebay (I have a URL if you need one). This probably isn’t ideal for a PCB design later though, for that you likely want power MOSFETs which may need heat sinks.
(edit: I forgot the 600MA for your stepper motor in the current calculation so

.5A arduino + 2A UV leds + .6A stepper .8A heater + .12 A fan = 4A@12v

so a 5A 12v power supply is probably correct. As well as you are possibly already aware, you shouldn’t look at the UV leds when they are running as UV can damage your eyes.