When it comes to tuning a bandsaw to cut straight you must check the swing angle of the arm relative to the bed, if it swings on an angle it will cut on an angle, next leave the support arms that have the guide wheels in one position, constantly adjusting the cut length inbetween them causes problems as they are seldom made square and will tilt the guide rollers ever so slightly,,,have a 200 dollar cheapey bandsaw,,,tuned it up,,,that took some time,,,but it cuts so square that when I chuck up a piece of pipe or round bar in the lathe,,,there is no depth to a facing cut,,,it takes time and patience to make these cheaper tools work the way they are supposed to,,,but it can be done if you have the will and the time to do it...