This is an Bridgeport Milling Machine optical measuring system. It operates like an old school DRO. It is fully functioning and works amazingly well. It “reads” the table position in both the X and Y axis using optical lenses to view the glass scales, then transposes them measurements into the viewing screen. The viewing screen looks similar to a ruler, but is graduated in. 001, with a smaller scale below for. 0001 It is original Bridgeport equipment. It is currently installed on my milling machine and I use is almost everyday. It is accurate to. The viewing devices are mounted on aluminum dovetail brackets the have thumbscrew adjustments. The whole system bolts up to the milling machine using the factory Bridgeport holes. It could probably be made to retrofit to any kind of mill. It has a power supply with it that converts 110v power to 6 v DC, that powers the lamps for viewing. It uses little 6v motorcycle bulbs, readily available at auto parts stores. The only real drawback to this optical system is that you can not zero out the scales after you find and edge, bolt center, etc. You will have to manually keep track of your starting point, but it is not hard, and it works really well. I have seen on forums that these are actually quite rare. The original manual for the system is still available online. Were a little dimmer than normal, and I have not changed them. I have had better luck with high quality bulbs from Napa, but was being cheap. I will pack these very securely as the glass scales can be very fragile while moving, however they are very secure and protected when installed on the machine. There is a rubber protection strip that mounts above the scale as well to help protect from chips and fluids. These are very cool, work well, and have a certain Bridgeport coolness to them that any Bridgeport aficionado should appreciate. I also have these for sale locally, so I reserve the right to end the listing early if I have any offers locally. The item “Bridgeport Mill Optical Measuring System, old school cool, rare DRO” is in sale since Tuesday, October 27, 2015. This item is in the category “Business & Industrial\Manufacturing & Metalworking\Metalworking Tooling\Equipment Specific Tooling\Milling”. The seller is “patriotsteel” and is located in Loveland, Colorado. This item can be shipped to United States.
