I was working on a Mitsubishi Bridge at Frontier in Gardena last week. After seeing extraordinary positioning problems (.1" or more errors in various positions on the 150" travel), we discovered that the tape scale was very loose. For those of you who are unfamiliar with tape scales made by Farrand / Inductosyn or Mitsubishi, they need to be stretched. It is hard to tell how much they need stretching ( I had to bring our laser to stretch this one), but this one is TOO LOOSE.
After proper tensioning using the laser, this axis had only point in 150" that was .0008" out of position. Most points were between 0 and .0004" out.
http://www.youtube.com/watch?v=Evz57rDIbJI
http://www.youtube.com/watch?v=Evz57rDIbJI
