--- title: Why To Consider A Belt Cleaner's Angle Of Attack description: Explore the impact of blade angle on conveyor belt cleaning efficiency and maintenance. Learn about positive and negative rake blade choices. --- [Skip to content](https://foundations.martin-eng.com/knowledge/conveyor-belt-cleaner-angle-of-attack#main-content) [![Martin Engineering Signature Logo](https://foundations.martin-eng.com/hs-fs/hubfs/MartinEng_Sig_2c_RGB.png?height=40&name=MartinEng_Sig_2c_RGB.png)](https://foundations.martin-eng.com/en/knowledge?hsLang=en) - Topics Show submenu for Topics - [Belt Conveyor System Basics](https://foundations.martin-eng.com/migration/en/knowledge/basics-of-belt-conveyor-systems) - [Mistracking](https://foundations.martin-eng.com/migration/en/knowledge/conveyor-belt-mistracking) - [Conveyor and Component Damage](https://foundations.martin-eng.com/migration/en/knowledge/belt-conveyor-and-component-damage) - [Carryback and Belt Cleaning](https://foundations.martin-eng.com/migration/en/knowledge/material-carryback-and-belt-cleaning) - [New Technology](https://foundations.martin-eng.com/migration/en/knowledge/new-technology-and-innovation) - [Material Flow](https://foundations.martin-eng.com/migration/en/knowledge/material-flow) - [Safety](https://foundations.martin-eng.com/migration/en/knowledge/belt-conveyor-safety) - [Dust Management](https://foundations.martin-eng.com/migration/en/knowledge/dust-management) - [Maintenance](https://foundations.martin-eng.com/migration/en/knowledge/belt-conveyor-system-maintenance) - [Spillage](https://foundations.martin-eng.com/migration/en/knowledge/material-spillage) Open main navigation Close main navigation - Topics Show submenu for Topics - [Belt Conveyor System Basics](https://foundations.martin-eng.com/migration/en/knowledge/basics-of-belt-conveyor-systems) - [Mistracking](https://foundations.martin-eng.com/migration/en/knowledge/conveyor-belt-mistracking) - [Conveyor and Component Damage](https://foundations.martin-eng.com/migration/en/knowledge/belt-conveyor-and-component-damage) - [Carryback and Belt Cleaning](https://foundations.martin-eng.com/migration/en/knowledge/material-carryback-and-belt-cleaning) - [New Technology](https://foundations.martin-eng.com/migration/en/knowledge/new-technology-and-innovation) - [Material Flow](https://foundations.martin-eng.com/migration/en/knowledge/material-flow) - [Safety](https://foundations.martin-eng.com/migration/en/knowledge/belt-conveyor-safety) - [Dust Management](https://foundations.martin-eng.com/migration/en/knowledge/dust-management) - [Maintenance](https://foundations.martin-eng.com/migration/en/knowledge/belt-conveyor-system-maintenance) - [Spillage](https://foundations.martin-eng.com/migration/en/knowledge/material-spillage) - [Request Assistance](https://info.martin-eng.com/request-assistance) [Request Assistance](https://info.martin-eng.com/request-assistance?hsLang=en) Hi! How can we help you? - There are no suggestions because the search field is empty. 1. [Foundations™ Learning Center](https://foundations.martin-eng.com/knowledge?hsLang=en) 2. [Material Carryback and Belt Cleaning](https://foundations.martin-eng.com/knowledge/material-carryback-and-belt-cleaning?hsLang=en) # Why To Consider A Belt Cleaner's Angle Of Attack ## Choosing the Right Cleaning Blade Angle for Belt Maintenance and Efficiency The angle of attack for the cleaning blades against the belt is a crucial consideration. Generally, there are two options: positive-rake (or peeling) blades and negative-rake (or scraping) blades. ### **Positive-Rake Blades** Positive-rake blades are positioned against the direction of belt travel, while negative-rake blades are inclined in the direction of travel, typically at an angle of 3 to 15 degrees from the vertical, depending on the type of splice. Blades installed vertically, perpendicular to the belt at installation, have a zero-rake angle. Metal blades in a positive-rake position quickly become razor sharp due to friction with the moving belt, posing a risk of costly damage if knocked out of alignment. They can also experience high-frequency vibration, [causing them to "chatter" and repeatedly jab their sharp edges into the belt cover](https://foundations.martin-eng.com/en/knowledge/conveyor-belt-cleaner-damage?hsLang=en). ### **Negative-Rake Blades** ![Angle of Attack Positive Negative FLC](https://foundations.martin-eng.com/hs-fs/hubfs/Angle%20of%20Attack%20Positive%20Negative%20FLC.jpg?width=383&height=287&name=Angle%20of%20Attack%20Positive%20Negative%20FLC.jpg)In contrast, negative-rake blades may accumulate material on their inclined cleaning edge, potentially reducing effective contact for cleaning. However, all belt cleaners, regardless of the angle of attack, require regular cleaning and maintenance to prevent buildup. For [primary cleaners](https://foundations.martin-eng.com/en/knowledge/primary-conveyor-belt-cleaners?hsLang=en) applied at low pressures against the belt, a positive rake is generally considered acceptable. However, for [secondary](https://foundations.martin-eng.com/en/knowledge/secondary-conveyor-belt-cleaners?hsLang=en) and tertiary locations where higher cleaning pressures and the use of metal blades pose greater risks to the belt, splice, and cleaner itself, negative-rake blades are recommended. 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