Be sure to mark both steel channels
Step 6: Cut the marked panel with a circular saw using a wood cutting blade. For best results you can use a table saw.
Step 7: Cut the 2 marked rails with a reciprocating saw, chop saw, or hand hack saw.
Step 8: After all the pieces are cut, you can chamfer or route cut edge of poly panel and file off sharp corners on the cut edge on steel channel.
Step 9: Now simply reassemble board components. Be sure to not spin out black mounting screws when reassembling. Your board should be your desired length. For this example it will be 45"
Check out this basement shooting lane. With the this ability to cut we were able to wrap around our customers basement to optimize the provided space.