- Joined
- Apr 25, 2024
- Messages
- 51
I needed a hardness tester to test the hardness of cylinder heads and other engine components.
Years ago, sales reps would give garages and reconditioning shops a simple tester based on the Shore rebound principle. I made a copy of those for myself but I was disappointed with it because it was too fast to get repeatable results by visual observation. I then made a more sophisticated version which replaced my poor old man's observational skills with electronics and an Arduino.
Then when preparing this post I saw how the use of a camera or smart phone could turn the original version into a really useful instrument. This multi-disciplinary post describes both versions. There is mechanical, electronic, programming and simple maths content but the original version only uses the mechanical, so do not be frightened off if electrons bring you out in a rash.
These really need to be seen in action so I prepared two videos, part 1 describes the mechanical stuff and discusses hardness testing in general and part 2 looks at the electronics (very simple). Part 2 also shows a way to make a very simple tester with the electronics replaced by a mobile phone or other camera.
However, video is not the best format in which to present schematics and programmes so I have also prepared a PDF file. The PDF contains the Arduino coding which can be used to make your own hardness tester.
Here is the PDF: https://s3-us-west-1.amazonaws.com/hmt-forum/tony_foale_hardness_tester.pdf
Watch part 1 before part 2. I suggest watching on Youtube to see it full size and right through until the end.
Note that the infrared diodes in the schematic in the videos are shown reversed, but the schematic in the PDF file is correct.
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Years ago, sales reps would give garages and reconditioning shops a simple tester based on the Shore rebound principle. I made a copy of those for myself but I was disappointed with it because it was too fast to get repeatable results by visual observation. I then made a more sophisticated version which replaced my poor old man's observational skills with electronics and an Arduino.
Then when preparing this post I saw how the use of a camera or smart phone could turn the original version into a really useful instrument. This multi-disciplinary post describes both versions. There is mechanical, electronic, programming and simple maths content but the original version only uses the mechanical, so do not be frightened off if electrons bring you out in a rash.
These really need to be seen in action so I prepared two videos, part 1 describes the mechanical stuff and discusses hardness testing in general and part 2 looks at the electronics (very simple). Part 2 also shows a way to make a very simple tester with the electronics replaced by a mobile phone or other camera.
However, video is not the best format in which to present schematics and programmes so I have also prepared a PDF file. The PDF contains the Arduino coding which can be used to make your own hardness tester.
Here is the PDF: https://s3-us-west-1.amazonaws.com/hmt-forum/tony_foale_hardness_tester.pdf
Watch part 1 before part 2. I suggest watching on Youtube to see it full size and right through until the end.
Note that the infrared diodes in the schematic in the videos are shown reversed, but the schematic in the PDF file is correct.
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