Those of you who are working with fuel grains in the 150mm / 5.5-6 inch diameter range, what are you using for your motor cases and liners? The largest I've done before is 98mm, and I used as much off the shelf Aerotech hardware as I could. Now I need to do something larger in a hurry at work and I'm hoping to find a source of pre-made carbon phenolic tubes between 5.5 to 6 inches in diameter. Any sources or ideas? Other things to try? -Daryle