Thank you very much for the information. I will probably go 4″. I love the link you provided to the foam cutter. What a great idea! I have plenty of spare rc parts around to throw something together. Thanks again for the wonderful design and for providing us with all of the information and files to allow us to create this amazing multi purpose machine! I may end up just printing the parts off on my da vinci jr (plastic needed for your 3d printer) and skip throwing the extruder on the mpcnc (just go right for the dewalt). We will see. I have another roll of pla getting delivered Wednesday (hatchbox silver). I may go with a black and silver design for your 3d printer.