I'd like to take a quick post to provide a tutorial on how to use the Easy Research Rocketry Cutting and Coring Jigs. They are currently in stock and available in both 29mm and 38mm sizes! 29mm Cutting and Coring Jig 38mm Cutting and Coring Jig These jigs make cutting and coring propellant quick and accurate using a utility knife, drill bit (5/16" for 29mm, 1/2" for 38mm), and power drill. No lathe necessary! Step 1: Cutting your propellant grain to length 1. Gather your Cutting and Coring Jig (body and spacer), necessary drill bit, hand drill, utility knife, and a stick of freshly cast propellant! 2. Remove spacer from the body. Insert the propellant stick into the body of the jig until it bottoms out. The propellant stick should be a nice snug fit that doesn't spin freely, so you may need to peel or friction fit to achieve the proper fit. 2a. Bonus pic: just to show what I meant above, I drew a line at the top of the jig to show how the cutting jig spacing works. That line is 2" from the end, perfect! 3. Use your utility knife to cut through the grain using the body of the jig as a guide. Apply even pressure and gradually work through the grain making sure to keep the knife as perpendicular to the grain as possible. 4. Here's what the grain looks like after it has been cut all the way through. The final step is to gently push the grain out of the jig using a dowel or the shank of your drill bit. Here are the four example grains I cut for this tutorial. Identical lengths and clean cuts! After the jump: Coring your grains using the jig!