ImpactATC - Automatic Tool Changer Module for ER20 CNC Spindles

Upgrade your hobby CNC router with a compact automatic tool changing system designed for standard ER20 spindle setups. ImpactATC uses a mechanical impact-tightening principle to loosen and tighten the collet nut automatically, allowing repeatable tool changes without manually handling spanners during a job.

ImpactATC is a compact automatic tool changer module designed for hobby and small workshop CNC machines using ER20 spindle systems.

Unlike traditional pneumatic or motorised tool changers, ImpactATC is based on a simple mechanical impact mechanism. The module uses the spindle’s own rotation and controlled engagement with the tool holder to loosen and tighten the ER20 collet nut. This makes it a practical upgrade for users who want automated tool changes without replacing their entire spindle setup.

The system has been developed and tested on a workshop CNC router and is aimed at makers, small-scale manufacturers, and CNC hobbyists who are comfortable modifying and configuring their machines.

ImpactATC is not a plug-and-play commercial ATC spindle. It is a workshop-developed module for technically confident users who want a low-cost, flexible route to automatic tool changing.

Key features

• Designed for ER20 spindle setups
• Enables automated tool loosening and tightening
• Uses a compact mechanical impact mechanism
• Suitable for hobby CNC routers and small workshop machines
• Can be integrated into custom CNC macros
• Helps reduce manual intervention during multi-tool jobs
• Developed and tested in a real workshop environment
• Designed with open, modifiable CNC workflows in mind

Benefits

• Spend less time manually changing tools
• Improve repeatability during multi-operation CNC jobs
• Avoid interrupting jobs to loosen and tighten collet nuts by hand
• Add ATC capability without buying a full industrial ATC spindle
• Useful for prototyping, small-batch production, engraving, cutting, drilling, and multi-tool machining workflows

Important note

ImpactATC requires machine setup, testing, and integration. You will need to configure your CNC control software, tool change positions, spindle speeds, and macros to suit your own machine.

This product is best suited to users who are confident with CNC setup, G-code/macros, and mechanical adjustment.

G-code

You can find tool loading and unloading macros here:

https://github.com/sn3ro/ImpactATC

I will also provide you with all the technical support to make it work on your machine.