How do I switch my Duet from Wifi to Access Point Mode Wifi?

To put your Duet Wifi into Access Point Mode please complete this guide:

2. Connecting your Duet to a Network - Access Point

After that guide is completed and you are inside WorkBee Control.

Go to File Management > System Settings > Edit config.g

Change the follow section:

; Configure Connection - ENABLE ONLY ONE OF THE BELOW THREE

M552 S1 ; Enable Wifi Network

;M552 S2 ; Enable Access Point Mode

;M552 S1 P192.168.2.14 ; Enable Ethernet - Change IP Address to suit

To:

; Configure Connection - ENABLE ONLY ONE OF THE BELOW THREE

;M552 S1 ; Enable Wifi Network

M552 S2 ; Enable Access Point Mode

;M552 S1 P192.168.2.14 ; Enable Ethernet - Change IP Address to suit

Once changed your board should restart and now permanently be in Access Point Mode.