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First exposure

A project log for open-hardware transparent polygon scanner

laser scanner which uses transparent instead of reflective polygon

HexastormHexastorm 10/29/2018 at 23:152 Comments

Succeeded in making my first exposure today. At the moment, I am working with cyanotype paper. This is pretty cheap, 50-70 eurocent per sheet, and easy to develop with water.
The dosage was not optimized.  The polygon speed was 2400 RPM. The laser driver was set at 50% of max power.  Each line was exposed 10 times, so the speed of the scan head was something like 0.2 mm per second. The line speed of the scanner was 1 m/s.  The laser frequency is 400.000 Hz.
Besides the not perfect dosage, there are several other issues. The laser goes through and over the prism. So lines are visible in the end result. The text in the final image is flipped,

Discussions

Hexastorm wrote 11/01/2018 at 22:15 point

Thanks! and for liking my Github repositories. Trick now is to mitigate the inaccuracies of the frame with smart software.  I plan to measure the current laser spot size,  the cross scan error and how repetitive the stages are in X and Y.
I also need to see if my spot gets back at the same position if I re-stabilize my scan head or if it drifts over time.
I hope I can do the trick with a raspberry pi camera version 2 and the current t-belt driven stages. That would keep the final system very cheap. We will see.

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darkomenz wrote 11/01/2018 at 15:07 point

Nice glad to see you are still working on this project.

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