Revised MK3 Extruder Indirect Filament Sensor

thingiverse

This remix is the result of combining two key components:\r\n\r\nDirect filament sensor (https://www.thingiverse.com/thing:3223513) by martin_au, Revised MK3 extruder (https://www.thingiverse.com/thing:2843264) by vekoj.\r\n\r\nI aimed to resist the urge to redesign more than necessary to add the bearing and maintain the aesthetic of vekoj's design.\r\n\r\nThe screw required for the bearing is a M3 X 6mm. For installation instructions on the bearing and an excellent video, refer to martin_au's thing, as this was his original concept. I believe I reduced the interference between the flanged bearing and the nominal filament path to achieve smoothness in anticipation of using the MMU2.\r\n\r\nI also straightened out the sensor in the body, mainly because my OCD wouldn't let me place it at an angle to avoid redesigning the x-carriage, apologies.\r\n\r\nAdding the flanged bearing necessitated modifying the extruder body as well as the x-carriage and the filament sensor cover. These are the only parts I modified, so they're the only ones included in this thing.\r\n\r\nI also included a STEP file of the entire extruder with these parts incorporated.\r\n\r\nYou'll notice a filament sensor cover labeled MMU2. I have an MMU2 that I hope to connect soon and this sensor cover is designed to hold a PC4-M10 fitting so you can eliminate the small PTFE tube and pass the PTFE directly into the extruder from the MMU2.\r\n\r\nThis is what you're seeing in the photo.\r\n\r\nI realize printing the sensor clamp on its side seems unusual, but I wanted features on both sides and printing with supports wasn't working for this part, so I rotated it to print on its side.\r\n\r\nIt prints a little rough around where the bearing goes, but this part is only designed to keep the bearing in place, so it shouldn't be an issue.\r\n\r\nThings are sized so that the M3 x 6mm screw supporting the bearing will end up in the clamp. If you accidentally use a screw that's too long, you'll damage your sensor! There's no need to tighten the bearing screw too much since it's just an axle for the bearing... just snug it up.\r\n\r\nSame thing goes for the sensor clamp... I managed to strip the plastic out on my 1st test print because I was trying to tighten the clamp too hard.\r\n\r\nAt the moment, all I've done to verify that the parts are working is to print a small section of the extruder body and x-carriage and assemble them as shown in the image.\r\n\r\nI removed the filament sensor from my extruder and installed it into this small assembly and then connected it back to the printer.\r\n\r\nWith the filament sensor turned on, I went to the support menu and under the extruder status I could see that the sensor properly detected movement of filament.