Looking to buy a Romer Absolute Arm for checking parts while still chucked in the machines. My part has an ID ±0.0005" and an OD of ±0.001". Does that exceed the accuracy and capability of the arm?
Matthew D. Hoedeman , what would be tightest tolerance for a diameter that you would use an arm for? ±0.005" What about distance measurements? Why are arms not as accurate as CMM? because of the number of encoders vs a stationary CMM?
Well, you have to look at how MANY encoders there are (6 or 7, depending on the model of arm) compared to a CMM (3). Then look at the SIZE of the encoders, for a CMM, each encoder is the length of travel in that axis where an arm has a round encoder that is, what, 1/20th of the 'length' of movement you can have in that direction (or less). <50mm diameter encoder for 450mm of length.
Matthew D. Hoedeman , what would be tightest tolerance for a diameter that you would use an arm for? ±0.005" What about distance measurements? Why are arms not as accurate as CMM? because of the number of encoders vs a stationary CMM?
Well, you have to look at how MANY encoders there are (6 or 7, depending on the model of arm) compared to a CMM (3). Then look at the SIZE of the encoders, for a CMM, each encoder is the length of travel in that axis where an arm has a round encoder that is, what, 1/20th of the 'length' of movement you can have in that direction (or less). <50mm diameter encoder for 450mm of length.
