CTC Dual / Bizer filament sensor bracket

thingiverse

A Custom Cable Bracket for the CTC Dual Printer to Detect Filament End-of-Reel Sensitivity \r\nIt Utilizes Optical Sensors Rather Than Microswitches, Search eBay or Similar for 'Arduino Slot Optocoupler', As a Sample Advert (Not a Recommendation) https://www.ebay.co.uk/itm/161817129903\r\n\r\nThe Sensors Slot into the Bracket from the Back and are Secured in Place by Being Clamped to the Rear of the Machine. \r\n\r\nThis Design is Meant to be Used in Conjunction with an Octoprint Plug-in to Pause Printing When a Reel is Expended, or Even Automatically Switch Extruders. \r\n\r\nThe Trick to Using These Sensors is to Fill Most of the Gap with Something Opaque, Leaving Only a Narrow Path for Light to Pass Through That Can be Blocked by Filament. \r\nThe Cross-Hole Between the Two Arms of the Sensor Needs to be Smaller Than the Filament to Allow the Filament to Block All Light; I Used a 1.5mm Drill to Finish Out the Sensor Tunnel After Printing, and Sensors from Different Vendors Might Require Smaller or Larger Holes. Alternatively, the Analogue Output Pin of the Sensor Board Could be Used. \r\n\r\nThe Filament Path Hole Was Finished Out to 2mm. \r\n\r\nThis Bracket Includes Provision for a Set of PTFE Guide Tubes, Lower Ones to Keep Filament on Spools and Upper Ones to Guide Filament into Extruder; It is Not Yet Clear if Either Offers an Improvement. \r\n\r\nThe Guide Tubes are a Simple Push-Fit into 4mm Holes in the Part; Forces on Both Tubes are Such as to Push Them into the Part Rather than Pull Them Out, so Proper Pipe Fittings are Unnecessary; These Will Probably Need Cleaning out with a 4mm Drill After Printing. \r\n\r\nPrint the Part As-Up-Loaded with Support Set to "Touching Bed" for Best Results.