Wall Mount Gravity Rewind Spool Holder

prusaprinters

This is a wall mounted space saving spool holder that uses gravity to rewind the spool when using the MMU2s. You reuse the axles and bearings that came with your MMU2 kit.Print instructionsTo mount, push the end of the bowden tube from the back of the MMU into the hole on the end of the "Frame". Move the "Frame" on the wall so the tube has a graceful curve into the MMU with no kinks and screw it to the wall. Next take “Rack Mount” and mate the concave side to the end of the frame away from the bowden tube. Tie the “Penny Weight” to “Rack” with enough length of monofilament to keep the weight clear of a loaded filament spool as it turns. Place “Rack” and weight onto the "Rack Mount" and secure it with the screw in “Pivot Clamp”. Press the bearings that came with the MMU kit into the ends of the “Hub”. Screw the “Springs” into the “Hub” using 3x10mm screws being careful to make sure the longer side of the spring is pointing to the spool loading end of the hub. Snap and or glue (depending on the tolerances of your printer setup) the “Pinion” into the wall side of the “Hub”. Using the shafts that came with your kit, insert a shaft and the assembled “Hub” into the “Frame”.When loading filament from a spool into the MMU, you have to be sure to engage the “Rack” with the “Pinion” manually by turning the rack as you feed filament from the spool, otherwise the hub remains freewheeling (which is built in to ensure you can spin the spool by hand without worrying about either running the weight into the spool, or rewinding the weight in the wrong direction. As filament is feeding the weight lifts up the wall until the “Rack” runs out of teeth and then ratchets in place for as long as filament is leaving the spool. As soon as the filament is back feeding, the weight is forcing the “Rack” to engage the “Pinion” and run the spool backwards to take up the slack in filament. The “Rack” is large enough to have enough teeth to not lose engagement with the “Pinion” in normal MMU filament parking maneuvers. If you manually spin the spool backwards, the “Rack” runs out of teeth and the stop lever falls onto the top of “Pinion” and keeps the weight from unwinding and allows the spool to freewheel. You will need some coins or washers to use for weight you load into the the "Penny Weight" part.Here are links to videos of the Spool Holder:https://youtube.com/shorts/zbp1pkDGtjM?feature=sharehttps://youtube.com/shorts/F9m28KpjKcM?feature=sharehttps://youtu.be/WCwYL-h1qEohttps://youtube.com/shorts/zbp1pkDGtjM?feature=sharehttps://youtube.com/shorts/mpouKYjCeg8?feature=share