Notes on making 3d printers based on polymerizing resin.<\/p>\n
Modifying a projector<\/a> May need to remove UV filters, replace with a Hot Mirror Filter \/ IR filter.<\/p>\n MakerJuice<\/a> selling reasonably priced UV curable resin. SubG+<\/a> Other resin printer projects<\/strong> Top down of bottom up polymerization?<\/strong> Continuous Top-Down DLP Experiments<\/a><\/p>\n Option:<\/strong> Print resin from a ink jet printer head<\/p>\n Bottom up printing presents a challenge because the part will stick to the bottom of the tank. This is handled by 1) using a non-stick surface (Sylgard 184 polymer $60 0.5 kg, PDFE sheet, FEP sheet<\/a>), 2) using a tilt \/ raise action between layers to break the adhesion and allow resin to move between the tank bottom and part.<\/p>\n Tests of materials to coat vat floor<\/a><\/p>\n Option:<\/strong> CLIP<\/a>, uses “an oxygen-permeable membrane lies below the resin, which creates a \u201cdead zone\u201d (persistent liquid interface)”.<\/p>\n Possible membranes: TPX film<\/a> (Mitsui) \/ Polymethylpentene, or PMP, 25 Barrers<\/a>, “slight haze” High >50 Barrers, but not commercially available: PTMSP, TR 450-1, PIM-1<\/a> PDMS Elastosil Superclear Silicone Sheet – 200mm sq<\/a> Making PDMS films<\/a><\/p>\n Option:<\/strong> Add a non-miscible liquid layer between the tank bottom and the part. For example, tetrachloroethene, or perchloroethylene (dry cleaning fluid, sold on Amazon, $15) which is denser than water (1.622 g\/cm3) and has low solubility (0.15 g\/L (25 \u00b0C)). Or perhaps even an oil layer (lighter than water, but may adhere to the bottom). One problem with this is the flow of resin into the gap between the part and tank could pull this fluid away from its layer.<\/p>\n Or add a sandwich–glass, circulating oxygen carrier fluid (water or perfluorocarbon), PDMS sheet. This oxygenates the PDMS while providing a solid support. This is a bit complicated and the layers will affect the image quality.<\/p>\n Perflurocarbons: Perfluorodecalin, 25g \/ $25<\/a><\/p>\n Another option is to support the PDMS with air pressure from below to equal the fluid pressure from above. This would require a glass \/ pressurized air \/ PDMS sandwich, again affecting the image quality.<\/p>\n Material sources<\/strong> Links Notes on making 3d printers based on polymerizing resin. Modifying a projector Projector mods site 3dprinter Projector mods site May need to remove UV filters, replace with a Hot Mirror Filter \/ IR filter. MakerJuice selling reasonably priced UV curable resin. SubG+ Bucktown Polymers, $176-$310 \/ gallon 5W UV LED, Mouser, $28 385-390nm 500mW LHUV-0390-0450, […]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"open","ping_status":"open","template":"","meta":{"footnotes":""},"class_list":["post-323","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/jimlund.org\/blog\/index.php?rest_route=\/wp\/v2\/pages\/323","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/jimlund.org\/blog\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/jimlund.org\/blog\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/jimlund.org\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/jimlund.org\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=323"}],"version-history":[{"count":14,"href":"https:\/\/jimlund.org\/blog\/index.php?rest_route=\/wp\/v2\/pages\/323\/revisions"}],"predecessor-version":[{"id":1673,"href":"https:\/\/jimlund.org\/blog\/index.php?rest_route=\/wp\/v2\/pages\/323\/revisions\/1673"}],"wp:attachment":[{"href":"https:\/\/jimlund.org\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=323"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\nProjector mods site<\/a>
\n3dprinter Projector mods site<\/a><\/p>\n
\nBucktown Polymers<\/a>, $176-$310 \/ gallon<\/p>\n
\n5W UV LED,<\/a> Mouser, $28 385-390nm 500mW<\/a>
\nLHUV-0390-0450, 2W UV LED, 470-1000mW $39<\/p>\n
\nChris Marion, DLP printer and 3DLP Host Software<\/a>
\nGary Hodgson DLP resin printer<\/a>
\nVideo of resin printer testing\/build<\/a>
\n3 D L P rint<\/a>
\nDLP printer less than $200<\/a>
\nVery simple DLP printer: Chimera<\/a>
\nBo Pang with PDMS membrane<\/a><\/p>\n
\nThe surface layer of the resin resists polymerization due to oxygen. So top down polymerization requires a stronger light (running through the resistant layer to the resin below. It also presents challenges in 1) getting the resin layer the correct depth. The part may need to be dipped then raised. 2) Some printers include a wiper to set the liquid layer thickness. 3) Bubbles can form as liquid moves around the part, 4) The part can only be as tall as the tank depth, and enough resin to fill the tank must be used, 5) The resin surface height must be calibrated after filling the tank.<\/p>\n
\nPTFE FEP, oxygen permeability 11.6 X 10^3 (cm3\/m2\u00b724 hr\u00b7atm)<\/a>
\nPTFE PDA, oxygen permeability 6.7 X 10^3 (cm3\/m2\u00b724 hr\u00b7atm)<\/a>
\nPDMS (mechanically weaker), oxygen permeability est. 1380 X 10^3 (cm3\/m2\u00b724 hr\u00b7atm), 600 Barrers<\/p>\n
\nOxygen permeability table<\/a>, another<\/a>, another<\/a>, another<\/a><\/p>\n
\nPolyimide clear, strong, oxygen permeability 3800 mL\/m2 \u22c5 24 hr MPa, 25 cc\/(100 in2 \u22c5 24 hr \u22c5 atm) (1\/4 of PDMS?) 0.5 – 7 Barrers
\nCytop<\/a>, ~oxygen permeability 8 Barrers<\/p>\n
\n1 Barrer=1\u00d710-10 cm3 \u00d7cm\/cm2 \u00d7sec\u00d7cm Hg<\/p>\n
\nPDMS Ultra Thin Silicone Film – 30 Shore – 250mm Wide
\nBest would be Teflon AF2400, second best Teflon AF1600. Oxygen permeable, fairly strong<\/p>\n
\n5.5 inch 2K 2560×1440 Durable LCD Screen<\/a>, $82 ebay. This translates to 47.25um pixels.
\nFEP Film for UV 3D Printers – 5mil (0.127mm) Thick – 6 Pack<\/a>, $30.<\/p>\n
\nForm 3 SLA Printer Teardown, Bunnie Style<\/a>
\nFormlabs Form 3 Teardown<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"