I did a lot of research on the subject of making my own motor cases. I'm still doing the research, but I have decided to build my own aluminum motor cases. Starting with Terry McCreary's "Experimental Composite Propellant" book, I found that aluminum is the best all around motor case due to it's strength, light weight and ability to tear during a cato and not throw shrapnel everywhere. This is why Aerotech and Kosdon and many others use aluminum. It has a very good strength to weight ratio. Some experimenters use phenolic paper tubes and fiberglass tubes for single use motors. You have to know your motor specs before using a certain case material to make sure that it can handle the pressure with a safety margin. There are different types of aluminum to use. The most common used in model rocket motor cases is 6061 T6 drawn aluminum tubing. This is seamless tubing with an ultimate tensile strength of 45,000 psi and a yield strength of 40,000 psi. PVC pipe has also been used with success using ammonium nitrate motors. Since I have restored my metal lathe, I had a chance to start making Aluminum snap-ring motor cases. I have made several motor sizes from 29mm up to 176mm in many lengths up to 48 inches. Check out the motor case pictures including several graphite nozzles I have made using my lathe.
When I started making motors, I found that I also needed to buy the casting tubes and liners. Since I was making my own motor cases, why not make my own liners and casting tubes as well. I found a great PDF from Apogee Rockets for about $5.00 on how to make your own motor tubes written by Terry McCreary. After reading through and getting all the materials I started testing the sizes to fit the motor cases I have built. The hardest part of the job was finding the mandrels to fit the size I needed. Once this was done I am now able to make as many paper tubes and liners as I need for a fraction of the cost. These paper tubes are just as good and strong as paper tubes you would buy for model rockets. If you take your time they can look and feel just the same. My first batch you can't even tell the difference unless you look real hard.