# Fitting the screen in the Vieira MCO hammer mill

URL: https://moinhosvieira.com.br/en/fitting-the-screen-hammer-mill-vieira-mco/  
Updated on: 2026-11-04  
Other languages: Español: https://moinhosvieira.com.br/es/montaje-de-la-criba-molino-vieira-mco/ · Português: https://moinhosvieira.com.br/montagem-da-peneira-moinho-vieira-mco/

> In the Vieira MCO mill the screen sits loose inside its frame: fit the screen into the frame and place the assembly in the grinding box, with the frame guide pin in the guide hole at the bottom of the box.

## Step by step

1. **Switch the mill off and wait for it to stop.** Never change the screen right after switching off: wait for the rotor to stop completely. Wear protective gloves to handle the screen.
2. **Place the screen in the frame.** The screen is supplied separately from the frame. Fit it carefully inside the frame. It works loose: it does not need to be fastened.
3. **Open the grinding box door.** Open the door to reach the bottom of the grinding box.
4. **Fit the assembly with the guide pin.** Place the assembly (screen and frame) inside the grinding box, fitting the frame guide pin into the guide hole at the bottom of the box.
5. **Close the door and check.** Close the grinding box door properly and check the fit before starting the mill.

## When to check the screen

- **The product particle size has changed:** the screen may be damaged or poorly seated in the frame or in the guide hole.
- **Metallic clicking inside the mill:** besides a foreign object, it may be the fit of the screen in the frame.
- **Output has dropped:** the screen may be worn or clogged.

See what to do in each case in [troubleshooting](https://moinhosvieira.com.br/en/troubleshooting-hammer-mill-vieira-mco/). The screen hole size affects the result: a finer screen tends to give a finer product. To choose the right screen for your product, talk to our team.

When ordering a new screen or frame, give the model shown on the mill identification plate.