Seth Carpenter’s Work Log

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  • Post last modified:February 26, 2024
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  • Post category:Work Logs

Fall 2023 Start

Project Update 1 (9/28/2023)

These first couple weeks will be key in defining the goals and function of our coco-fab robot. We have decided at the moment to use a tank of water to heat the cholate. We also want it to take a fun path through some flexible tubes on its way to our extruder and pump ends, which are external to the tank. We would like to 3d print molds for the chocolates to get some cool shapes, maybe even the enterprise logo 🙂

This week I pretty much just drew some sketches like the one pictured above, and did research. I looked into pumps for high viscosity substances like our chocolate when its melted, and found out we should use positive displacement pumps. I also did some research on food-safe PLA and PETG but i think coating our molds will just be better for various reasons. That’s the gist of this week, brainstorming!

Project Update 2 (10/7/2023)

Since the last project update I modeled the first two molds for the chocolate, and made the STL files to print whenever they are needed. On the right we have the enterprise logo, and on the left our schools logo which I will mirror in the slicer so it faces the correct way. The molds are 6cm by 6cm which I thought would make a good small chocolate bar for giving out at events. Hopefully we get to add more flavors with time so you can try out a few at once! We have decided on using almond bark, which is a chocolate flavored coating that melts easily and consistently.

I have also done more research on components for melting, pumping, and dispensing the chocolate substance. Unfortunately, pumping the chocolate into the molds for cheap is turning out to be more of a pain then anticipated. Most good pumps are for commercial use and are hundreds of dollars. I have found a few high viscosity pumps amazon for 20-50 dollars, and we may just buy one to try sometime in the future. Thought, after doing some research I am concerned about how we would clean the pump after we are done using it. If the chocolate hardens inside it will most likely break. There are heated pumps available, but these are also expensive. Lots to still consider in the coming weeks, maybe even order a few parts!

Project Update 3 (10/28/2023)

Since the last project update we have finalized a design we will prototyping and assembling for the duration of this semester. We have a three chamber tank for heating 3 different types of chocolates, but we will just be starting with one for now. Next, we have a temperate controller and heater for each tank so we can tune water temperatures for each chocolate if needed. On top there will be syringes for pumping the chocolate through a tube into the modes shown in the Project Update 3. These will eventually be automated with stepper motors to make a simple and cheap pump design. The syringes are better then a normal pump because they will not get clogged by chocolate, and are easy to take apart and clean. All of the food safe, positive displacement/ high viscosity pumps were hundred’s of dollars which is too much for our first prototype. Once the parts arrive we will begin the physical construction and testing of our very first prototype which is quite exciting! Big updates hopefully coming in the following weeks.

Project Update 4 (11/4/2023)

This week our parts arrived however we are still working out a time to build it together. Not much past the panning stage last week has been done, other then outlining some goals we have an an order of assembly. Our first step will be to assemble the heating element circuit and test it with a small volume of water in one of the three tanks. After that we can 3d print housings and attach it more robustly. Then we will start planning out the chocolate pump and mount the chocolate syringe in the tank. The goal after all of this is to successfully melt the chocolate so we can work on pumping it, and then 3D print the molds. After that we can work on attacking some of our value added goals the rest of the semester.

Spring 2024 Start

Project Update 1

The basic design changes I have come up with so far for this semester is to automate the chocolate pumping process, as it was plumped by hand last semester. In addition, I plan to circulate the water between 2 tanks rather then keep it static to help with even heating of the water. Finally, we want to make the silicon molds for the chocolate this semester rather then using not food safe 3d printed ninja flex like in testing. We have many other goals that will be posed to this worklog as we get the details hashed out.

To-do List Week 4

-Start stepper motor CAD. The goal here is to mount the stepper to a rack and pinion assembly which will plunge the syringe forcing chocolate through the tubes.
-Assemble electronics once they arrive and test.
-Set up water pump and secure in the tank.
Concerns For the Week;
The only real concern I have is weather or not the stepper motor will be strong enough to plunge the chocolate, and I am not quite sure how we will design the rack and pinion.

Project Update 2

This week we had a meeting to make sure everyone knew their assignments to get us ready for the critical design review in a few weeks. I placed the parts order last week, however it still has yet to ship so I have been holding out on starting the CAD. I have sketched out some of my basic ideas above. For starters, I don’t know where exactly the syringe will sit in line with the motor and I am unsure of any of my dimensions till I can hold the stepper and make a guess. For convenience, I will be gluing 4 screws for each stepper threads up on the tank approximately 4 cm apart in a square. This will make all of the my 3d printed brackets in the future swappable so if they break or a dimension changes they can be removed. Next up I planned how the rack and pinion will sit in the syringe plunger so it interfaces with the motor well. I am hoping to cut some of the structure of the plunger away and add the track in.

To-do List Week 5

-Finish stepper motor CAD.
-Start rack and pinion CAD.
-Assemble electronics once they arrive and test.
-Set up water pump and secure in the tank.

Project Update 3

Referencing project update 1, the image above shows the general operation and design of our device. Initially it will start by just heating the water to melt the chocolate using the temperature controller and the 12 volt heater (red and green lines). Once the chocolate is around 60 Celsius we are ready to electronically pump it (orange and yellow lines). Using some code we will write in the next few weeks the stepper will rotate a gear on a rack and pinion plunging the syringe full of chocolate into the mold. It will then stop after a certain volume is pumped and we will repeat this process with the next bar.

Past Week & To Do List

The image above of the stepper motor bracket is all I have really been able to do this week. We placed our order 3 weeks ago at this point and I was hoping to at least get the stepper motor so I could print the above bracket and test fit it on the top of the tank so I can design the other components like the gear and the rack and pinion. Unfortunately, without any physical parts I would pretty much just be guessing dimensions which is a waste of time for me to CAD or print. I am really hoping the parts are there Monday so I can start the to do list below

-Start rack and pinion CAD.
-Assemble electronics once they arrive and test.
-Set up water pump and secure in the tank.
-Run a dry test of stepper motor spinning.

Project Update 4

Over the course of last week I made the rack V1 and V2, Gear V1 and V2, and Stepper motor bracket V1 and V2. In addition, our parts order finally shipped so we can start 3d printing and assembling before the CDR coming up. I have also disassembled all of last semesters project so that I can attach all of the new components and design the new parts. I am currently waiting on the last print to finish so I can test all of the V2 parts together. All of the things on last weeks To-Do list got done besides the water pump assembly. I also spent some time debugging the printers in the OSHE while waiting on other prints.

To-Do List

-3d print remaining parts and assemble.
-Set up water pump and secure in tank.
-Make new chocolate mold brackets that also secure tube.
-Make CDR slides.

Project Update 5

During this last week I was pretty busy with exams, however I was still able to get a few things done for the project. I made a Version 3 of the stepper bracket and printed the stepper bracket, gear V2, rack V2, and assembled all of the parts I have printed so far. I can tell after assembling that some spacers are going to need to be 3D printed to keep the plunger stable or else the gear will un-mesh kind of like in the picture.

To-Do List

-Design water pump 2 way splitter
-Order smaller diameter tubes for the water circulation
-Come up with a good way to drain water out of tank instead of flipping it upside down link last semester
-3D print parts for holding pump