Sorry kbarry. To the best of my knowledge you can't fit a 1/2" shank into a 1/4" collet (a quart into a pint pot!). You can get a 1/2" router with collet adapters to reduce to 1/4". Depending on the size of the job you might want to consider upgrading to a 1/2" router to go with your bits. Alternatively, if the job is small, buy only the 1/4" router bits you need to do the job in hand.