1058 Service Manual link - Kavo

where the manual helps solve a complex, long-standing issue?

The 1058 uses a push-button chuck that is notoriously sensitive to bur shanks. The manual reveals the secret tolerances: The bur must be inserted exactly 18mm. If it is 18.5mm, the fiber optic light path is blocked. If it is 17.5mm, the bur will wobble, causing chatter marks on the tooth. Kavo 1058 Service Manual