diff --git a/README.md b/README.md index 222b3d0fb2263c8064d0804010ce53d97557ac9e..171534bf1af2e943dfa0770e1ef3099777d62f7a 100644 --- a/README.md +++ b/README.md @@ -2,9 +2,9 @@ Rapid manufacturing of embossing tooling for permanently marking thin plastic. - + - + ## need As part of our covid-19 face shield production efforts, we need to permanently mark units that end up in hospitals with a few basic identifiers: a manufacturing batch number and a shortened URL for assembly instructions. The Zund needs to spend its time cutting rather than marking, and doctors have complained about the smell of laser-engraved text. @@ -40,4 +40,25 @@ The 101st test was performed on a scrap of 0.75 mm polycarbonate:  -Further cycle testing should be done to test long-term durability. +Later tests updated this process as follows: +- 0.25 mm Cu +- 5 mm letter height +- no electrochemical deburr +- sanding bottom rather than sides of letters +- reflowing solder under letters rather than tacking sides + +This updated process was used to fabricate a tool with the Project Manus face shield URL, minus dots (as these were lost). Laser micromachining took 40 minutes, while manual assembly took roughly 30 minutes: + + + +The tool was mounted with double-sided tape on a cold rolled mild steel bar, which was held to the press using NdFeB magnets (flipped sideways above for visibility). The tool produced acceptable results in 0.020" PETG: + + + +Embossing was also performed on stock with both layers of protective film still in place; prior to film removal, the URL was legible: + + + +However, legibility was reduced once the film was removed, suggesting film should be selectively removed from shields prior to stamping: + + diff --git a/img/url_multitest.jpg b/img/url_multitest.jpg new file mode 100644 index 0000000000000000000000000000000000000000..309382574801536825af8c528a5f7d983a9df721 Binary files /dev/null and b/img/url_multitest.jpg differ diff --git a/img/url_protectivefilm1.jpg b/img/url_protectivefilm1.jpg new file mode 100644 index 0000000000000000000000000000000000000000..fc69139ca959725aa0f60e1651ff35a381728d05 Binary files /dev/null and b/img/url_protectivefilm1.jpg differ diff --git a/img/url_protectivefilm2.jpg b/img/url_protectivefilm2.jpg new file mode 100644 index 0000000000000000000000000000000000000000..f0186d887dcbdb89c8ed597976ef7f690948600f Binary files /dev/null and b/img/url_protectivefilm2.jpg differ diff --git a/img/url_tool.jpg b/img/url_tool.jpg new file mode 100644 index 0000000000000000000000000000000000000000..812926a6c0e8f8e65dfb835aeb4820d46c7176db Binary files /dev/null and b/img/url_tool.jpg differ