UV Resin Curing Cabinet | Final Code, Schematic, Bill Of Materials and Demo

August 12, 2015 / 1 Comment

Here’s a demo of the finished system:

In the end, it all turned out really well. Painting it white and using a white print stand was a good insight, the light reflects around the box pretty well for how few LEDs are in use.

The software flow chart has changed slightly. I removed the speaker as it wasn’t loud enough and added software debouching for the pushbutton interrupt service routine. Here’s that most recent version:

The interesting parts of the code are the cookResin function as well as the main loop of the Arduino:

void loop() {
  digitalWrite(BUTTONLED_pin, HIGH); 
  displayStaticState(0);
  if (BPRESSED == true) {
    cookResin(14400);
  }
}

void cookResin(unsigned long MAXTIMER){
  unsigned long SECTIMER = 0;
  
  writeLCDLines("CURING TIME REM:", "H:MM:SS  -:--:--");
  
  fadeLEDs(1,1);
  
  while ((SECTIMER &lt; MAXTIMER) &amp;&amp; (BPRESSED)) {
    digitalWrite(BUTTONLED_pin, HIGH); 

    String part0 = String("H:MM:SS  ");
    String part1 = secToHuman(MAXTIMER - SECTIMER);
    String line1 = part0 + part1;
    lcd.setCursor(0, 1);
    lcd.print(line1);

    int DMILSECTIMER = 0;
    while ((DMILSECTIMER &lt; 10) &amp;&amp; (BPRESSED)){
      digitalWrite(BUTTONLED_pin, HIGH); 
      Alarm.delay(100);
      //Alarm.delay(1);
      DMILSECTIMER++;
    }
    SECTIMER++;
  }
  
  if (BPRESSED == false){
    //start of cancelled cure end
    
    displayStaticState(2);
    
    fadeLEDs(0,1);
    
    
    delay(1000);
    BPRESSED = false;
    
    //end of cancelled cure end
  } else {
    //start of successful cure end
  
    displayStaticState(1);
    
    fadeLEDs(0,1);
    
    delay(1000);
    BPRESSED = false;
    
    //end of sec cure end
  }
  
  return;
  
}

void loop() {

digitalWrite(BUTTONLED_pin, HIGH);

displayStaticState(0);

if (BPRESSED == true) {

cookResin(14400);

}

void cookResin(unsigned long MAXTIMER){

unsigned long SECTIMER = 0;

writeLCDLines("CURING TIME REM:", "H:MM:SS -:--:--");

fadeLEDs(1,1);

while ((SECTIMER < MAXTIMER) && (BPRESSED)) {

digitalWrite(BUTTONLED_pin, HIGH);

String part0 = String("H:MM:SS ");

String part1 = secToHuman(MAXTIMER - SECTIMER);

String line1 = part0 + part1;

lcd.setCursor(0, 1);

lcd.print(line1);

int DMILSECTIMER = 0;

while ((DMILSECTIMER < 10) && (BPRESSED)){

digitalWrite(BUTTONLED_pin, HIGH);

Alarm.delay(100);

//Alarm.delay(1);

DMILSECTIMER++;

}

SECTIMER++;

}

if (BPRESSED == false){

//start of cancelled cure end

displayStaticState(2);

fadeLEDs(0,1);

delay(1000);

BPRESSED = false;

//end of cancelled cure end

} else {

//start of successful cure end

displayStaticState(1);

fadeLEDs(0,1);

delay(1000);

BPRESSED = false;

//end of sec cure end

}

return;

}

Again, this all should all be explained by the flow chart. The full source can be found at the bottom of this post.

The circuit schematic hasn’t changed at all since this post, here’s a fritzing of what’s going on:

Super simple, basically a screen and a button. The parts to make this are here:

Assembly is super straight forward, if you’re trying to build one and have any questions, let me know!

Thanks for reading!

UV Resin Curing Cabinet | CAD Modeling And Physical Build and Installation

August 12, 2015 / Leave a comment

This past school year I too several classes related to 3D modeling. One class in particular, a class based around SolidWorks. I hadn’t really been able to use the software again, not having the tools to actually execute. MADE@MassChallenge really has the whole kit, 3D Printers, a 40W Laser Cutter etc. All the tools of a hackerspace as a part of my job. Here’s a “finished” model of the system:

Cure Cab Models

The frame is built out of:

.22in thick masonite painted black on one side
The frame is held together with a series of L brackets and machine screws from home depot
The front opening is secured with two metal hinges from home depot

There were a couple 3D modeled components as well:

The four feet

I ended up gluing these down with hot glue even though they have cuts for screws. In the end, it wasn’t worth it to use more screws and add more complexity.

The electronics enclosure

View post on imgur.com

There is a frosted acrylic sheet inserted in the top. One of the goals of this project was to show off the tech, and I think this does that quite nicely.

The knob assembly

View post on imgur.com

The knob has a stem that comes of the back and forces the hinge back, keeping the door closed. I wanted to try and keep things as simple as possible. The threads I modeled weren’t within tolerance. So I just glued the nut in place so the knob could rotate freely.

The print stand, for holding up the prints so they cure evenly

View post on imgur.com

It doesn’t make sense to have the prints just sit on the bottom of the frame. I also cut inserts that fit the inside of the print stand. This is so resin doesn’t cure to the print stand so it can be used many times while only needing to change the cardstock inserts.

Here are some more photos of the build process:

Cure Cab Build Photos

I’ll include the plans to build this whole assembly in the final post for this project once it’s all finalized.

UV Resin Curing Cabinet | Declaration and Software Flow

August 10, 2015 / Leave a comment

This project is the first of what I hope to be many in collaboration with the MADE@MassChallenge Hardware lab. The primary goal of this project is to speed up the time to delivery on prints coming out of the Formlabs Form 1+ SLA 3D printer using UV LEDS. Here’s a proof of concept of my circuit:

One of my tasks during my internship at MassChallenge was managing the queue of incoming models to be 3D printed on our 3D printers. Turnaround is often a pressing issue when doing this. It was often the case that teams had a deadlines or presentations that they needed parts for. Shaving even minutes off of the time from submission to receiving a fully processed part mattered quite a bit.

The Form 1+ is an amazing printer. If used correctly, the print quality can be much higher than the other 3D printer in MADE, a uPrint SE Plus by Stratysis; a printer almost 5 times the cost.

The post processing involved with the Formlabs has a steeper of a learning curve and leaves a lot of room for possibly destroying a part in the process.

The problem is not a fault of Formlabs, but rather a problem in the chemistry behind the resins used to create the parts. They are photopolymers, and need UV light to be cured. It is suggested that this be done through exposure to sunlight, but that takes quite a long time. I also have a sneaking suspicion that there are adverse effects of doing this, but I can’t prove any of that as of now but hopefully more on that later.

As this is a project that will be used by people other than myself, it is worth it to commit time and effort into the user experience. Atheistic should also be taken into account as this has to stand up next to the beautiful design of the Form1+. In short, a UV LED strand, a 3A switch, a power supply and a Light tight box could functionally do the trick, but in this case a polished design is as important as the functionality.

At this point, a push button switch, a rocker switch and a 16×2 Character LCD will be the UI. The software flow is as follows:

I’ll post the final code when I finish, but this chart is basically what the code running in the above video looks like.

Thanks for reading, more on the physical construction in the next post.

esologic

Tag: laser cutting

UV Resin Curing Cabinet | Final Code, Schematic, Bill Of Materials and Demo

UV Resin Curing Cabinet | CAD Modeling And Physical Build and Installation

UV Resin Curing Cabinet | Declaration and Software Flow