Modular Motor Can (MMC): How to Install and Swap Motors
By High Power Model Rocketry | Published: 2026-11-03
Category: Guide pratiche
Learn how to install a Modular Motor Can (MMC) in your 2.63-inch kit and swap motor configurations safely. Follow these steps for a secure, reusable motor mount.
Quick Answer
Install the MMC by bonding its coupler tube into your 2.63-inch airframe with the provided centering rings, then secure the motor tube and shock cord mount. Swap motors by removing the can and inserting a different motor tube configuration.
Why a Modular Motor System Changes Your Build
A modular motor can (MMC) lets you fly different motor sizes in the same rocket without rebuilding the motor mount. Instead of committing to one motor tube, you install a reusable can that accepts interchangeable motor tubes. This is especially useful if you want to experiment with high-power rocket assembly or adapt to different flying conditions.
The trade-off is added complexity: you must ensure the can is securely mounted and the motor tube is properly aligned. Also, the MMC is designed for our 2.63-inch kits, so it won't fit other airframe sizes without modification.
When to Use an MMC (and When Not To)
Choose an MMC if you plan to fly multiple motor configurations or want the flexibility to swap motors at the field. It's also a good choice for high-power rocket assembly where you might want to test different thrust levels. However, if you only ever fly one motor size, a fixed motor mount is simpler and lighter. Also, the MMC adds some length and weight, so check your rocket's stability before flying.
Step-by-Step MMC Installation and Motor Swap
- Test-fit the coupler tube: Slide the coupler tube into your 2.63-inch airframe. It should fit snugly but still be removable. If it's too tight, sand lightly; if too loose, you may need to add a wrap of tape or use a slightly thicker adhesive. Check that the coupler tube extends fully into the airframe and aligns with the forward and aft openings.
- Bond the coupler tube: Apply a ring of epoxy or strong adhesive around the coupler tube where it contacts the airframe. Insert the coupler tube and wipe away excess adhesive. Ensure the tube is straight and centered. Let the adhesive cure completely before proceeding; a misaligned coupler will cause motor misalignment.
- Install the centering rings: Slide the two coupler centering rings over the coupler tube and bond them to the airframe interior. These rings keep the can centered and provide a thrust surface. Make sure both rings are fully seated against the airframe walls and bonded securely.
- Attach the shock cord mount: Thread the 2-foot Kevlar shock cord through the screw eye and tie a secure knot. Then screw the eye into the forward centering ring or coupler as designed. Pull test the shock cord mount to ensure it won't pull out under deployment loads.
- Insert the motor tube: Slide the appropriate motor tube into the coupler tube from the aft end. It should slide in smoothly and stop at the forward ring. Secure it with the provided retainer or friction fit as instructed. The motor tube must not protrude beyond the aft end of the coupler; it should sit flush or slightly recessed.
- Swap motors: To change motor configuration, remove the motor tube (if retained with a removable method) and insert a different motor tube size. Ensure the new tube is fully seated and secured before flight. Always double-check that the motor tube is locked in place and the motor fits without play.
Product Facts
- Modular Motor Can (MMC): Includes coupler tube, two coupler centering rings, one screw eye, 2-foot Kevlar shock cord mount, and the appropriate motor tube for the selected size. Everything needed for a complete motor mount and recovery anchor is in one package, simplifying your build.
Modular Motor Can (MMC)
