Brush Replacement (no hardware needed) for Roborock S7, S7 Plus, S7+, S7 MaxV

Brush refresh for Roborock S7 series

• Uses original brush core and bushing
• No glue
• Easy to print
• 3 hard (core) parts, one TPU part
• Reusable core parts and lock ring.
• TPU part can be replaced quickly when worn out and locked in place with the lock ring.

Preparation of the original brush (read before starting)

• Cut off the worn-out soft red material.
• Remove most of the foam (see picture below).
• Leave a thin layer of foam and the old glue. Stop when it becomes difficult to remove. Perfection is not necessary. (see picture below)
• The printed parts will fit over the remaining foam and glue. They will flex over the prepared core.

Printing hard parts (PLA/PETG/..)

• Orient the two core pieces and the locking part as shown below
• No supports needed
• Consider using a small brim for all parts

Printing soft TPU part

• Orient the brush with the side down. 
• Make sure that the side with sloping internal edges is down (pictures below)
• 2 wall loops
• Gyroid 5% is sufficient to make the brush soft

Mounting

• Slide the two inner core parts towards the center, aligning the notch with the matching pin.
• Align the two parts.
• If the parts are very loose (mine were quite tight), some glue may be necessary. Ensure both core parts and the lock ring (bushing side) fit tightly
• Remove the lock ring before sliding on the brush.
• Slide the brush onto the bushing side of the core. The brush can only be inserted in one direction (see the picture below with the core on the right and the bush without bristles on the left).

• Insert the lock ring on the bushing side to lock the brush in place and install the gray parts from the original brush.

• Make sure that the brush is centered.

Example prints

• Clas Ohlson generic PLA (black)
• Polyalkemi TPU 95A – Flexible Transparent