In my experience working with press brake tooling, achieving perfect bends at 90 degrees tends to be straightforward, but angles like 135 degrees can introduce noticeable errors. This is often due to the machine's programming and die setup rather than mechanical limitations. For example, when bending a sheet metal to 135 degrees, the press brake may consistently overshoot or undershoot the target angle because the tooling geometry and springback are not accounted for properly. A useful technique I've found is to engage in precise angle correction using software controls integrated within advanced press brake systems like those mentioned by METEC. These systems allow for fine adjustments such as changing the die opening width (e.g., switching from V12 to V18 tooling as referenced), and recalibrating the back gauge position to correct the angle deviation. It's also important to input correct material thickness and type data into the control system to help anticipate springback. Another key factor is performing manual angle measurements during setup and adjusting the correction values accordingly. For example, if your first bend measures 92 degrees instead of 90, you can tweak the correction angles (a1 and a2 as shown in some software interfaces) to compensate. Then reassessing at 135 degrees and making similar incremental corrections can significantly enhance accuracy. It's critical to save these settings once perfected, which can then be applied consistently for repeated production runs. Additionally, synchronizing the timing of step sequences and the dwell time for the ram to hold the bend position can influence bend precision. Using the software to program delays and repetition counts, as demonstrated for complex angled bends, helps maintain consistency. In summary, achieving precise 135-degree bending requires a combination of correct die selection, programming precise correction values, and iterative adjustments informed by actual measurements. While it might seem challenging initially, mastering these adjustments ensures high-quality sheet metal bending beyond simple right angles, improving your overall fabrication process.