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Final Project

Easy Make Oven

Pitch:

Find yourself longingly looking at 3D prints and wishing they were pancakes? Tired of eating the same round or rectangular cake shape every year? Well fret no more because EZ-Make Oven uses an edible filament to create edible 3D masterpieces!

Description

I love making pancakes with my little siblings, but even though Apple keeps on coming up with upgrades pancakes haven’t been innovated on in a while. As such I decided to simply combine pancakes with something else I really love: 3D printers. How cool would it be to eat a syrup-covered replica of the Eiffel tower? I know I'm not alone in finding that prospect intriguing. My project idea is to bring baked goods into the third dimension as an additive practice rather than a subtractive one. I was mainly thinking pancakes (because I’m biased and love pancakes), but it can't be that hard to extrapolate and change based on batter. As a child I had an EZ-bake Oven, which is a device that cooks batter using a 100 Watt lightbulb, my product would get a similar name of EZ-Make Oven for its ability to both cook and make complex edible shapes whilst maintaining the shape of a traditional oven. FDM printers work by taking a solid material, expending energy to liquefy it, and allowing it to cool back to a solid. SLA printers work by curing a specific layer of liquid resin in a tank with a laser and building on the layers. SLS printers use a powdered "filament" and fuse the powder together with lasers. My proposed project would start with a liquid filament (like SLA) but have to put down layers of it (like SLS and FDM) it would also have to cook/cure the layers (like SLA and SLS) without burning previous layers. The “bed”/ bottom-layer-curing would likely be created like a griddle, the other layers will be cured using a heat gun, and sending jobs to the printer will probably involve a crude slicer that gets really low-resolution slices of the image and tells the extruder/heat gun how to move. My two current ideas include a one extruder version and two extruder version. For the one extruder, I won’t have to completely remake the slicer but will have to make the machine double-pass each layer, essentially taking normally produced g-code (from somewhere like Cura or Prusaslicer) and telling it to repeat its previous move, once for laying down batter and once for cooking it. The two extruder version would involve using already-built software to slice the file for two extruders, one for cooking and one for laying down the batter. I think this project sounds really fun and it will be interesting to taste a cake/brownie or pancake that is cooked evenly throughout.

Background

I am a manus makerspace mentor, course 2A-6, and avid maker. I pretty much live at metropolis and know how to use most of the machines there and in the deep. I love CADing (have already CADded a model for the project) and have recently learned PCB design and manufacturing. I was also part of the team that won 3rd place at MakeMIT last year

Reality

Before considering the mechanical/electrical implications of this project and all the little things I'll need to get just right I'd like to say that I quite love the idea of a 3D printing oven, but in practice, it seems really difficult… Far too difficult for a final project with such a close due date… so I’ll simplify. Simplifying the dimensions is really easy to upgrade upon at a later point whilst making my life much easier at the moment, so I’ll build a 2D printer instead of a 3D one. I’ll also you pancake presets or g-code the machine comes preloaded with to constrain the shapes that are being made, this will:
Allow me to make the shapes pretty refined
Not have to worry about compatibility with slicers
Restrict people to only the shapes I deem worthy enough

The 4 shapes I have chosen have been my go-tos throughout the semester: turtles, dolphins, triangles, and narwhals. Fear, not A 2D shape-restricted printer is not my end goal and there are ways around this limitation. Pancakes are usually served stacked and caked with butter and syrup. I will take advantage of this fact to create 1-7 individual pancakes that can be stacked during post-processing to create the perfect 3D shape. Now that’s all fine and well but what about shape restrictions? If I have time or more accurately if the TAs have time to help me figure it out, I’ll try to find a way to simply augment the g-code files from a slicer and process from there. The path function from mods seems pretty handy for doing this or maybe something from Ultimaker Cura slicer. Either way, the freedom of choice will be considered at an appropriate time.

Real Reality

In the end I went with a design that gave limitless freedom, well within the constraints of an etch-a-sketch, in order to incorporate more freedom into my design I decided to provide a controller that could control the x and y axiis this was accomplished using potentiometers that could be set to certain positions that corresponded to certain positions on the bed. This presented a few problems the most notable was that occasionally the controller and axiis would drift, which is easy enough to fix in software by initializing the position of my extruder and then translating the potentiometer values into absolute positions the first of which (whatever value you left the controller at) would be the position the extruder moves to at the beginning of your job. This was a product of using potentiometers for the controller, mapping a joypad of buttons would have allowed me to bypass this but potentiometers were more fun.

Plans vs Outcome

I’ll have to purchase a lot of the non-negotiable parts, but I’ve already begun working on a temperature sensor for the bed. Homemade 3D printers are becoming more common and there are kits where you can just assemble your own so all I have to do is take the basic parts of a printer and recreate/repurpose them for my needs.

I'll compare my initial plans with my end product end this snazzily color font

The BED

I plan to purchase a griddle for my bed this is a safe way to create the heat that I need. I want the bed to be moving in the Y-axis as well so I’ll mount it on linear rails driven by…

First off my inclusion of this reflection toatlly ruins my dramtic entrance to my next section, but I wanted to comment that this part of my plan stayed nearly exactly the same with the exception that I decided not to have the bed moving on the Y-axis but instead create an XY gantry entirely from scratch. This serves two purposes:
I found an amzingly cute griddle online IT'S BLUE, it's giant, but it's blue, and so I scaled up my entire model to match this griddle size, suce a large and heavy and hot griddle could not feasibly be moved, plus it's dangerous to expand the burn zone especially for those of us who are more accident prone.
I kept talking about how much I loved cadding this entire semester, but I have mainly done just for show cool looking cads that didn't have to fit parts and such things, there are so many tools that I have yet to explore such as importing parts to get all of my dimensioning right. So that's what I did I cadded the entire gantry myself and figured out an implementaion of it, things weren't perfect but it worked and I'll go more into more detail about this later.

The Motors

Not sure why these needed their own section I just thought it would be more dramatic. I’ll purchase some high-quality stepper motors to control the head and bed, I may or may not have time to at least set the frame up to hold 3.

I ended up using four stepper motors which meant I needed to create four stepper motor boards hopefully four stepper motor boards capable of interfacing with each other... Through I2C. The image provided below is my board for modular I2C connecting stepper motor boards.

The frame

I think I’ll stick to a mainly metal but partially 3D printed frame, just because I’d love to learn/work with welding and the griddle will be very hot and 3D prints melt, and I eventually want to cook higher layers with a heat gun meaning even more wildly firing heat. Which brings me to the next part…

Because I decided not to implement the heat gun idea and got wildly distracted by the cool inflatable projects over wildcard week I didn't end up welding the frame, #D prints are fairly heat resistant, PLA is heated to between 200 to 220 degrees Celsius to be extruded through a 3d printer meaning as long as I keep the frame as about two inches larger than the griddle I should be fine. And indeed I was, and I created offsets to put my 3D printed carriage higher above the bed and just dip my extruder which is a silicon tube with a metal funnel closer to the bed. Nothings melted so far, even though the carriage does get a little warm. Below I'll put pictures of my cads for the frame which took quite a bit of integration as I had to get a bunch of parts to fit together without using any T-bolts. The frame is primarily composed of aluminum extrusion t-rods, but ones I sourced from in Edgerton so they did not quite fit all my wishes (I didn't have enough to build the full frame and just outlined two sides). I learned a lot about working with metal, namely cutting and drilling and sanding it, I can now confidently say that I know how to operate the cold saw, metal sander, and how to change the speed on a drill press with gears and belts instead of a lever for controlling speed. I also used the laser cutter to engrave the back plate and cut out the front and back plates along with their interfacing holes and slots for the belt and motor mount.

The Chill

Because chill sounded cooler than just saying that I’ll need fans to keep it from overheating.

The "chill" didn't need to exist because I gave space in between the heat source and the 3d printed components.

The Axiis

I’m 90% sure that that’s the plural of axis and I’ll need at least two, probably in the form of purchased linear slide rails. I could try to make my own linear motion kit and I’ll keep an ear out during machine-building week. This is my main goal to apply what I've learned in this class and my meche classes to create a working gantry.

So it turns out that xy gantries (as in the prebuilt ones) are really really expensive, so I made my own using different cadded parts anf components along with bearings, aluminum extrusions, cut metal pieces, and slides. I could go more into detail here but basically I focused on making my own gantry without relying on external CADs in the end I had to vertically offset the extruder on the x axis and messed up the parallelness of the axis by misalligning metal plates. It would have been better to cad this piece, but it was far too close to the heat source and thus had to be metal, or possibly resin. But I was unsure of how well a resin part would hold up. My axiis' misallignment isn't the biggest problem, but it does limit bed size as one y slider reaches it's limit before the other and the whole thing is forced to stop. I am extremely proud of the gantry and although it's a little shaky (which could be fixed by tightening the screws on the base or for a more permanent fix I could adhere the entire frame to a wooden plate for stability). For the Y axis I used two slides and created an offset mount to hold the x axis. The y axis is composed of two sides but only one is powered which coupled with the misallignment produces some unecessary friction but not too much. The x axis goes around an aluminum extrusion and is mounted directly on the y's, the motor is screwed directly into a plate. The carriage is inspired by umbuntu but introduces slides for adjusting tolerances around the bearings, a dual hose grabbing end effector, and a slide for tightening the belt. There was one point when the belt became too tight and the acrylic back plate broke, causing me to have to redo a bunch of cuts prints and designs. But it all ended up fine and the next time I used a longer belt.

The Extruder

I will need a rather thick extruder head that is fairly heat-resistant as well and it has to be easily detachable for cleanups and refilling. I will load a giant squeeze bottle up with batter and it will need to be pushed through the head, I’ll probably also want a way to clean it up.

I want to keep this entire thing 100% food safe so I can actually use it so I used food safe syringes to hold the batter and thick but squishy silicon tubes to transport the batter, I didn't want to stress my axis by mounting the syringe directly to carriage but in hindsight my axis could probably haave taken it, and cleaning the tube is quite annoying. The tube needs to be really thick to hold all sorts of different viscocities of batter, but it needs to extrude a small amount, not a glob, so I attached a metal funnel to the tip, they are technically icing funnels so everything is legit and food safe.

The Pump

I’ll have to find a way to “extrude the filament” or push the batter, I’ve seen both pumps and mechanical rigs that push it out, I’m leaning in favor of pumps but I am saying that far removed from the process and I love falling back on mechanical systems when electric ones inevitably fail me.

We tested peristaltic pumps in archshop for machine building week, but our design di not allow for the modularity required for food safety (you couldn't detach and clean it) So I decided to make an easily detachable one. Well technically two (I want to have either a topping or other color option extruder as well). The pumps were all cadded with adjustable tightening slides to find the right setting for the tube and batters caracteristics. My main mistake was using a press fit homemade sprocket attachment for the motors using a 3d printed part, meaning that after many times of removal the fit became too loose and my emergency set screws didn't help because the 3d print didn't hold threads. The pumps worked perfectly fine up until presentation when I went to change the parts for clean ones to ensure food safeness and broke one pump and loosened the fit on the other. It is now back in working condition after larger set screws were acquired.

The Controller Board

This will be the crown jewel of my experience in this class and inevitably the hardest part of the assignment, I will need a board capable of driving 3 stepper motors, 2 fans, a pump, an OLED screen, a rotary switch or if that’s too hard several cute molded buttons. I will probably use a SamD21 because it’ll need a lot of processing power and I should make a breakout board for it to make all the components I need easily accessible. I will also make a temp sensor to check and adjust the temperature.

I decided to use my dev board from networking week it has a SamD21 and has many many input/output pins. This won't be as complex as the controller board but can perform the same function. In the end I got the board to work but never used it because I learned of a better way. Using modular things to create thing boards allows you to program them in java script rather than c with helful and easy functions. This did involve a lot of SamD21 soldering but I learned about the magic of solder paste and the hot air setup they have at EDS which made my life so much better, why solder SAMD21s any other way? I also rejoined the world of Eagle and learned to use the OtherMill. This was an exciting culmination of learning right at the final push. My old computer wouldn't run Eagle (it would just get sad and crash, so I tried with a new computer and it only crashed and lost my progress twice, which is infinitely better than it was before, but I still don't know whats wrong with Eagle or if its just a Windows thing). I have access to three OtherMills through Metropolis and am looking forward to being able to use them now that I know how to and how to get brd files instead of pngs, but it will never replace my love for the Illustrator + mods super team.

Change of Plans

THIS IS ME FROM THE FUTURE: so we just did output devices and the whole build a 3d printer control board thing is not happening, but I will build motor controllers to attach to the board. Also the machine in general is a lot of work so by using a peristaltic pump to directly move batter, I might get away with a bit more than I previously thought. Some changes for my sanity and that of future generations who will look back in shame at my failure: Really rough shapes if shapes at all, pumped directly with liquid pump thingy, simplify more if needed after talking with instructors.

This is me from farther in the future here to sum up my project.My proudest accomplishment is getting a potentiometer to control an xy gantry. Like clank this has so so many options for modular changes and addons. I was unable to get four stepper boards working, only 3 (one for each axis and one for the pump) but the extra tool spot could go to holding a spatula so you can push, scrape, and flip your pancakes off the griddle once you are done. Because the carriage is modular this is entirely possible as well as switching it out for a variety of other things like frosting dispencing and drawing for cakes that you can place under the gantry or cook directly on the griddle. So what does my product do, it does function as a pancake printer! Yes I have obtained sweet sweet success. Here's a video and some photos.
Pancake printers exist already, but my future goal is to have it create slices of 3d objects that can be assembled and the dual extruders allow for many more options. I designed stepper boards, a dev board, the frame, the gantry, and the modular version of the peristaltic pumps (based off the design from machine building week). I also used modular things to help with my course 6 inferiority. The griddle cost a lot of money but only because I wanted the blue one, and the steppers, syringes, and slides cost a bit together as well, but factoring out the cost of the griddle (it was neccessary for my project but ideally it would just interface with one responsible adult people who have to feed themselves already have) so the total cost was less than $100, (the steppers cost $55 by themselves). What worked was the gantry what most of the time works but is extremely sensitive and needs to be calibrated for every different pancake brand and recipe (really viscocity) was the peristaltic pump. I need to work more on presetting values for different pancake recipes and using the interface to allow you to choose between super thick to super thin batters. The control you get is also not the best so it's hard to make things, at least for me it was and here are some pancake prints to prove this.

Here is the Modular Things code I used

let Gantry = createSynchronizer([Xaxis, Yaxis])
console.log(Gantry)
Xaxis.setCurrentScale(0.75)
Xaxis.setStepsPerUnit(30)
Yaxis.setCurrentScale(0.75)
Yaxis.setStepsPerUnit(50)
Pump.setCurrentScale(1)
Pump.setStepsPerUnit(20)

Xaxis.setVelocity(100)
Xaxis.setAccel(100)
Yaxis.setVelocity(100)
Yaxis.setAccel(100)
Pump.setVelocity(100)
Pump.setAccel(100)

// let's do... get-set
loop(async () => {
let posns = await Promise.all([Potent.readPotentiometer(0), Potent.readPotentiometer(1)])
posns[0] *= 100
posns[1] *= 100
await corexy.target(posns)
Pump.relative(1)
}, 100)

Xaxis corrsponds to my stepper motor for my X axis, Yaxis corresponds to the Y axis stepper motor, Pump refers to one of the peristaltic pumps (I was only able to get 3 stepper boards working so the second pump had to be cut), and Potent refers to the modular stings potentiometer controller I was using. The first part defines a gantry, then sets values for the motors in the bounds of my axiis, then changes the motors position based on the potentiometer. All the while extruding the pump if you move.

Victory Videos