Wild Card
Assignment
- Design and produce something with a digital fabrication process (incorporating computer-aided design and manufacturing) not covered in another assignment, documenting the requirements that your assignment meets, and including everything necessary to reproduce it. Possibilities include (but are not limited to):
Reasearch
potato-plastic
4 axis setup
laser cutting material chart
Throughout the Week
This week their was many things I wanted to do. This includes making potatos into a plastic substitute and see how engraving on it with a laser cutter works and learning how to do a 4 axis mill with the shop-bot index rotary.
Potato plastic
Setup
For this part of the week myself and two other fab academy students, Dylan Ferro & Ryan Kim decided to do this part together. We started by finding a tutorial on how to make the potato plastic and found the one linked above. To start off we decided to just buy corn starch which was a valid substitute for the potato starch we needed from the potato. We did this, becuase of a time concern and just the concern of the mess it will all make when doing it, So we decided to just starch with store bought starch. The other materials you will need are glycerin, vinegar, and if you want food coloring.
Making plastic
Once we had all the materials we were ready to start the whole process. We started by getting 60 ml of water and mixing it with 1 tablespoon of corn starch.
We then added in 1 teaspoon of vinegar.
Next We added 1 teaspoon of glycerin.
After all that we chose to not add food coloring for now and started the mixing process we turned the stove on low while we mixed it constantly.
We waited for 5 mins before it started to thicken, so we could then turn it up to medium. After another 5-10mins it was ready, and so we poured it onto a piece of aluminum foil and spread it out over it.
We then let it rest for a day. While waiting we decided to make one more thing just in case we mess up the first one. But this time we decided to use twice the materials on every step, so we could have a bigger test and maybe a better spread. Here is what that piece looked like.
Results
Here are the two results for our plastic substitute that we made.
As you can see the first on, just as we thought was too thin, and we could not take off the aluminum foil without it breaking apart and folding in itself. Because of this we had no chance to engrave on this piece of substitute plastic. But on the second piece we did get that chance. While it was much thicker because we used twice the materials said too it still broke apart when we got it out of the plate. But these pieces where thick enough for us to be able to engrave on so we each grabbed one piece and tried to engrave on it. To do this We looked up the settings on the epilogue laser pro we had and found this chart which has a lot of the material settings that we could base our engrave setting on. In the end we came up with the settings of 300 DPI, 80% speed, and 100% power.
With this we were ready to cut, so I manually focused the piece of substitute plastic I was going to engrave onto then hit cut. Here is a video of it cutting.
And though it's hard to see in the video it worked great here is a picture of the final result.
Summary
From this part of the week I learned just how much the Epilog laser cutter can be used because it has settings for everything that you can change to cut almost any material. I also learned about how to create a custom material, and while it was not the perfect outcome And in the future I think I would like to actually make a mold for the material instead of spreading it out over a plate or something like that. Becuase I feel like that would be a better use case for the material.
Shop Bot Index Rotary
Set-up
The next thing I wanted to do during this week was learn how to use the index rotary for the shop bot, so I can learn how to make pens and other things further on. I started by following the tutorial linked above to learn how to hook it up and how to design files for it in aspire.
To start everything off Dylan Ferro put together the index 4th axis onto the shop bot and hooked it up into the motor driver on the back. We then test air cut to see if it worked and spun here is its first time spinning.
First Design
The next step after getting it to turn was to design a test file in aspire. To do this I set up the stock to rotary cutting and just put a square pocket cut onto the maker area.
I then went to the model area to see what it looked like to see if it even showed and here it was with its pocket cut.
I set it to a 1/4" flat end mill because in all the documentation I had seen it was one of the bits used and this was the first test, so we did not have a complete idea in what we were doing. But after the basic path was generated we sent it to the shop bot desktop. We then set up a wooden dowel and zeroed the machine front center of the wooden dowel.
And with this our first test was ready, so we hit cut. Here are some videos of it working.
As you can see it goes in lines across the whole wood, and then it turns a little then repeats this action over and over to cut the whole wood. And when you're done it will look like this.
Diving deeper
One I had done one test cut and kinda understood what I was doing I wanted to go further in depth and make a workflow for the whole process here is how it all went.
For my second attempt I wanted to make a miniature honey dipper t kinda shape, because I thought it would be cool. I started the design by setting up the dimensions of the dowel that I would be cutting in Aspire While also selecting the Rotary cut option.
I then had to design what one profile of the cut would look like, so I made one long part and then went up and down to get the honey dipper shape.
After getting the shape right I had to use the 2 barrier object sweep tool to sweep my whole design across the whole plain. To do this I selected both ends of the canvas and then selected my object and hit sweep Here is the result.
The next step after I was done making the design was to make it into a tool path, to do that What I had to do was use the 3d roughing toolpath option and select the 1/4" bit along with some other settings seen here.
And here is the result of that tool path in aspire
But one I had all of my tool path designed all that was left was to send it to the Shop-Bot Desktop Pro and cut it. I started with an air cut and when it looked like it was cutting ok I zeroed it onto the wooden dowel I was using and hit cut. Here are some videos of it cutting.
While the cut was looking good at first eventually the same problem that we saw earlier happened. It just stopped randomly in the middle of cutting and only cut in one big line not changing the height of what it was cutting at all as seen here.
While I did clean it up bit as seen below.
This did not get rid of the real problem. And this problem
was happening to Dylan Ferro & Ryan Kim too. Their cuts just stopped randomly and only cut one height for the wood. After comparing our pieces of wood we realized that how deep it cut was equal to the lowest point on our whole design that we cut, and it was not stopping cutting randomly. As seen in the picture below The lengths it cut for both Ryan Kim's cut and mine are the exact same.
Because of this we though that something about the setup in Aspire and the rotary motor we had set up did not match. Either the driver for the motors were outdated, or there was a step we missed while setting up. One possibility that we believe it could have been is that the post-processing for the shop bot desktop indexer was out of date because of the way that all of our g-codes got messed up in the same way.
Summary
While we may have not been able to figure out the rotary indexer we got some good attempts and will keep trying even after this week is over. When we get it to work I would like to try and make some pens using it. But enough about that From this part of the week I learned many things like how to design in 3d in aspire, and just about the shop-bot too. I will be able to use it much Better than before because of the experience for this week and can't wait to keep trying to get the indexer working.