Comparatron Demonstration - DIY digital optical comparator
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- Опубліковано 24 жов 2022
- github.com/theserialhobbyist/...
www.instructables.com/Compara...
cameroncoward.com/comparatron...
Comparatron is a DIY digital optical comparator for taking precise measurements of physical objects, useful for reverse-engineering. - Наука та технологія
Very cool project! I might try this out. A couple of things came to mind that might be interesting to try:
- Using OpenCV to quickly capture multiple keypoints (aptly named for the demo) along the contour of the object. A calibration routine could convert the pixel space to world space so you wouldn't have to rely on the movements of the 3D printer for the measurement. With enough points, you could likely avoid needing to sketch in curves and go straight to automating the edge creation.
- Convert mouse left-click drags on the image view to printer movements so you could avoid having to jog around with arrows.
Thanks! Something like that would be awesome, but I think it is beyond my programming capability. Luckily it is all open source, so maybe a better programmer can make that happen!
The mouse click idea is interesting and I think I could probably figure out how to do it. I'll had that to my list of improvements to make when I have time, thanks!
Came here from Hackaday. This is awesome. One use that immediately cones to mind is tracing objects for cnc cuttingfoam organizers ("kaizen foam").
Excellent Work! You've inspired me too make one of my own using an Ender 3 for the control
Saw this on Hackaday! Great project. .
Thanks! Didn't realize it was on Hackaday, so thanks for the heads up!
Some improvements that come to mind: use 0.9 degree stepper motors with 1/256 microstepping interpolation with TMC2209 drivers. Add geared transmission to further increase the resolution.
With OpenCV you can detect outlines automatically. I suggest defining an area that encompasses the object at the start of each scan and let the camera make passes in x and y grid lines, looking for the contrast between the white backgroundvand the object.
Then move to Rhino's Grasshopper and make a script in there that automatically looks for the closest points in the point cloud data to connect the dots.
Great ideas! If I had built the machine from scratch, I definitely would have gone a similar route for the hardware. But in this case, I already had the pen plotter on had and so just used that.
yeah, this has lots of potential. A way to speed it up would be to take pics of the entire bed and stitch them together. Just like the commercial ($60K) units do.
That is a great idea. Love it. Just sold my Keyence IM 7020 and looking for something a tad more affordable!
This would be amazing with an algorithm that could follow the outline of objects
That would be cool, but someone smarter than me would have to figure out how to program that!
It already exists, it's when you take a photo with a macro lens from far away, apply a mask and then trace the mask in illustrator with the image tracer. I do it all the time. The only thing you need to do right is to make sure you use a good lens without barrel distortion, make sure it is aimed straight down and get the lighting around the object so you don't trace shadows.
It's quite easy but most people don't manage because they don't go 'all the way' when trying this.
The big benefit of using the machine in the video, is that the dimensional accuracy is better out of the box. But I still prefer the camera method since the camera can also be used for other jobs (multifunctional) and it takes less space.
@@MarinusMakesStuff Yeah, I did that for years, but always ended up frustrated (which is why I built this). Fighting lens distortion, trying to get the shot perfectly perpendicular, having to take the shot from far away, etc. all added up to me wanting another solution.
This is incredible! I would really love to see this expanded to work with lots of different motion systems. A 3D printer, CNC router, CNC mill, etc are all basically the same 3 axis motion system you've got here.
Thank you! I actually almost used a 3D printer, but I had the pen plotter collecting dust anyway. It should work work with anything that accepts Grbl g-code, so there is a lot of flexibility there.
@@serialhobbyism_official Oh that makes sense, that opens up a lot of options.
I'd be curious to see what the limitations on accuracy are - like if you put a 123 block or gauge block on it and trace the shape, how square and dimensionally accurate is the resulting DWG compared to a micrometer reading? Those would be some very interesting numbers with such an inexpensive motion system.
@@k4kfh yeah, I need to do some testing to find out. So far I’ve only tested linear repeatability. I’m actually working on a more rigid microscope mount to improve that. I should grab a 123 block to check that everything is square and true, good idea!
Interessting. I didn't see where you set the scale of your trace.
Would be great to use a game controller as a input. For Navigation and taking points.
Awesome idea!