Camera alignment issues
Posted: Wed Oct 04, 2017 9:05 am
As you know, I'm using Chinese endoscope type cameras. It turns out that the quality in the last batch was unusually bad.
The main issue is that the camera is not looking straight down compared to the chassis. On LitePlacer, this doesn't matter much, until the error is large: All measurements are done at the same Z level, and the distance of the camera center and the nozzle tip is measured in the setup. But the assumption only holds so far. If the error is large, the accuracy suffers.
In the latest batch of cameras, there were many units that were off unacceptably much. So, I tested the units I still had. The normal Z level of the LitePlacer depends on where you set the high limit switch. In my test setup, I tested the cameras about 75mm height. I had to draw a line somewhere: I trash the cameras where the center point is more than 5mm off. While doing that, I also noticed that the focus of a few units was off; those were rejected as well. (I ended up trashing about 40% of the cameras. Not good.)
If your kit was shipped October 3rd or earlier, and you got bad cameras, please get in touch and let me know if you need one or both cameras replaced.
My apologies for the inconvenience and troubles!
The main issue is that the camera is not looking straight down compared to the chassis. On LitePlacer, this doesn't matter much, until the error is large: All measurements are done at the same Z level, and the distance of the camera center and the nozzle tip is measured in the setup. But the assumption only holds so far. If the error is large, the accuracy suffers.
In the latest batch of cameras, there were many units that were off unacceptably much. So, I tested the units I still had. The normal Z level of the LitePlacer depends on where you set the high limit switch. In my test setup, I tested the cameras about 75mm height. I had to draw a line somewhere: I trash the cameras where the center point is more than 5mm off. While doing that, I also noticed that the focus of a few units was off; those were rejected as well. (I ended up trashing about 40% of the cameras. Not good.)
If your kit was shipped October 3rd or earlier, and you got bad cameras, please get in touch and let me know if you need one or both cameras replaced.
My apologies for the inconvenience and troubles!