Back to: SciTech Friday’s 2023-24
Today’s Video
Etching Metals
Extra video- go to the Aluminium section
Discussion
- What do you notice about the results for the metals that bubbled more?
- Why do you think that is?
- Some of the results are inconsistent. How could it be improved?
Experiment
We’re going to try electroetching.
Experiment Goal
To determine the advantages and disadvantages of different resists. A resist is something that will protect the metal from the etching solution so that it is not affected.
Procedure
Put on your safety gear! (Goggles; gloves optional.)
Carefully clean your sample piece of metal (aluminum) using the sandpaper, scotch bright, water, and IPA.
Mark of an area at the top that is big enough for the alligator clip or hook that will be outside the etching solution.
Under this area create a grid of rows, or rows and columns.
The top row of the grid will be the control made of two areas. One will have no protection from the etchant and one will be covered by a good tape that will protect the metal. The area where the clip goes is also part of the control. It shouldn’t be changed in any way as it will be outside the etchant.
In each of the other areas in your grid create a test pattern. Suggestion: make some thin and thick areas to see if the area of the resist makes a difference, and to see how much detail can be achieved.
Suggested resists: sharpie, posca pen, electrical tape, spray paint, vinyl mask, …
Make a solution of vinegar + salt. For just salt water only etchant, one suggestion is 2 cup salt to ~14l of water. Discuss with your group and make your own recipe. Heat (or add hot water) so the etchant is ~60˚C.
Set up the etch tank in a well ventilated area. Some gases will be released- potentially small amounts of hydrogen, oxygen, and chlorine.
Next connect your cathode (electrical connection for the -ve terminal) plate and put it in the tank. The Anode could be a piece of plate metal, or as simple as a steel nail.
Connect your items to test to the anode (+ve terminal) and place them in the etchant.
IMPORTANT: make sure the alligator clips or wire hooks are OUT OF the etchant. Both so they’re not damaged, and so you have a clear control area.
Turn on the power supply and set it to ~3V. Set a timer for 30 minutes. NB- to high a voltage may cause unwanted reactions and cause lower quality etching.
Observe the etching process at regular intervals.
At the end of the thirty minutes turn off the power supply.
Remove the samples and rinse under water.
Remove the resist materials.
Compare the results from different resists. Which worked best?
BREAK
Design Time
From Last Week
We’re going to build our own Einstein Puzzle, similar to these ->
Building Our Own Spectre Tile
Note: I suggest leaving the page view settings alone – we will be printing this on paper!
Also, change the document size to US letter- landscape or portrait.
Follow this video (from 7:40)
Make sure you save your file (on the public drive), and make a copy of your shape!
Next, add some curves or other patterns from edge to edge to decorate your tiles. You can make bigger lines by changing the stroke size. Play with the background colors.
Here are some examples of what I’m poorly describing (I mean the patterns on the tiles, not their shapes!)
When you’re happy with your pattern, group all the parts and scale it to a reasonable puzzle piece size.
Duplicate it across and down the page – Check with Drea or Julian when you think you’re done.
Making it with the Cricut
Drea and Julian will help you use the Cricut to cut out your tiles.
Testing
See how big a pattern you can make!
Break
Making a Platform Game
Carry On
Please continue working through MakeCode Arcade or start on the Godot tutorial if MakeCode arcade is too easy.
MakeCode Arcade
Introduction to the Godot Game Engine
Breaking News
Video for lunch- did I play this last week?!
