[sad] Sorry Twuntcat but then it's not possible for you to use Fastfix chucks. That's why I asked if your CDD 12 looked like the picture because there were older models that didn't have Centrotec and Fastfix yet. Seems you have the older CDD12, newer models had the FX added to the description to show they had a Fastfix chuck.
To use Centrotec you should get a newer drill or use the adaptor below.
[attachimg=1]