My BusyBee CT129 mill came from the factory with a digital readout on the quill travel, but these Chinese machines are definitly sub quality in the read out department. It quit working about 3 months after I got the machine, and in spite of cleaning it and installing new batteries, it never really worked right, and in the middle of building my Webster engine, it died completely. A call to the BusyBee customer service told me that a new DRO pack would cost $100. I also had an 8" Powerfist digital Vernier caliper that worked, but if I measured the same thing 3 times, it would give me 3 different answers, due to looseness in the head. Yesterday and this morning, I did some "mad modifying" and added the Vernier to the mill. The Vernier is now held steady enough to give repeatedly accurate readings, and I can now mill to depth with accuracy. The hardest part of the entire job was drilling a pair of 1/8" holes through the hard stainless steel body of the caliper. I went up to the lumberyard/hardware store, and purchased two 1/8" carbide concrete drills to accomplish that.----Brian