Introduction: How to Make CADaniels' Leg Magnetic Attachment Point (LMAP Mk. III)

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Hello there! After much reworking and testing, I've finally produced a working production model of the Magnetic Attachment Point (MAP). Currently, the only part of this system is the Leg MAP (LMAP), but I have plans for an expanded backpack module as well.

If you aren't familiar with the original design, the premise is the same: I wanted a way to carry my blaster through games without dealing with straps or bulky holsters. The MAP was the perfect solution to this. It takes up almost no space unless the blaster is on it and it doesn't hamper my movement at all. The magnets hold the blaster to the leg while the Velcro prevents the blaster from slipping off. The Velcro actually provides almost no holding force on the blaster.

I will say this ahead of time: this is not an easy build unless you know two things first:

  • How to operate a sewing machine
  • How to operate a jigsaw

You also need a lot of materials and a space to work in. Unless you are a very lucky or very determined person, you will not be able to build this in the average dorm room.

On to the build!

Step 1: Gather Materials and Tools

You're going to need a ton of stuff to make this. Make sure you have all of these before you start.

  • Strong fabric (preferably denim or better)
  • Good thread
  • Cardboard
  • Duct Tape
  • 1.5" Buckles
  • 1.5" heavy Webbing
    • 1 8" piece
    • 2 14" pieces (If your upper leg has a circumference much larger than 26" with pants on, consider making these longer.)
  • These magnets
  • Sticky back Velcro
  • Sew-on Velcro
    • 4 8" pieces
    • 2 9.5" pieces
    • 2 5.5" pieces
  • Thin cookie sheets made of ferromagnetic metals
  • Nerf Stryfe
  • Mounting tape that can hold at least 1 lb/2 inches (can be bought from Home Depot -- I use Scotch Extreme Mounting Tape (20 lbs.))

Note: If you can find any of these items for cheaper, do so. The only exception is the magnets. I have no idea how well other magnets work for this design.

You'll also need a bunch of tools. Make sure you have all of these before you start.

  • Rotary cutter
  • Seam allowance marker
  • Sewing machine
    • Zipper foot
  • Scissors
  • Seam ripper
  • Sewing pins
  • Metal zipper
  • Needle-nose pliers
  • Fabric iron
  • Jigsaw (or equivalent) with metal cutting blade
  • Tin snips
  • Heavy-duty gloves

Step 2: Make the Stencils

Cut these patterns out of your cardboard. Hi-res scans of the patterns can be found here.

Step 3: Check Fabric

Make sure that your fabric pieces are more than large enough for the interior plate.

Step 4: Trace Interior Plate Stencil

Trace the interior plate stencil to one of your pieces of fabric.

Step 5: Create 5/8" Seam Allowance

Use the seam allowance marker to make a 5/8" seam allowance around the stencil line.

Step 6: Mark Fabric

Mark up the tracings as in the image to indicate where you will put your zipper.

Step 7: Pin the Fabric Pieces Together

Pin the fabric pieces together with the marked side facing outward.

Step 8: Cut Fabric

Cut along the seam allowance (the dotted line). Be sure to cut the top in squared corners as shown in Step 6.

Step 9: Mark Fabric

Mark the fabric as shown. This tells you where the inside of the pouch will be. Marking the stencil again is just helpful later on.

Step 10: Place Velcro

Align and pin one of your 8” pieces of Velcro so that it sits on the unmarked side of the fabric. You may have to eyeball it so that it is inside where the stencil line is.

Step 11: Sew Velcro

Sew the Velcro on. Note the front and back (inside and outside) view.

Step 12: Sew Velcro (cont.)

Repeat Steps 10 and 11 with the other pieces of Velcro. In the image, these are ordered from top to bottom:

  • 8" piece (already done)
  • 9.5" piece
  • 8" piece
  • 5.5" piece

Once you've sewn these on as indicated in the image, repeat this process, mirroring the arrangement on the other piece of fabric.

Make sure the Velcro is NOT on the side marked "IN."

Step 13: Attach the Zipper to the Pouch

Step 14: Sew the Straps to the Pouch

Step 15: Sew the Pouch Closed

Step 16: Invert the Pouch

Step 17: Reinforce the Straps

Step 18: Trim the Interior Plate Stencil

Step 19: Cut the Plates

Trace your stencils onto the cookie sheet and cut them out with the jigsaw.

WEAR HEAVY GLOVES! The edges of these plates will be sharp and can cause severe injury if they cut you.

Step 20: Final Plate Preparations

Step 21: Attach Pouch Buckle

Step 22: Prepare the Stryfe

  1. Apply the mounting tape to the other side of the Stryfe plate from the Velcro as shown.
  2. Peel the backing off of the mounting tape.
  3. Apply the plate to the Stryfe on the left side (the side without the battery compartment). Try to line it up so that you can still access all of the screws necessary to open the Stryfe.
  4. To properly apply the plate, you might need to slightly bend the lower part of it. If you don’t want to do this, you can add more layers of tape as a spacer. This is not as strong, so it’s not recommended.

Step 23: Test the LMAP

Step 24: Warnings and Considerations

  • Do not activate the Stryfe motors while the blaster is magnetized. This may damage the motors. Only activate the motors when the blaster is in your hand and away from the LMAP.
  • Do not keep any electronic devices like cell phones or key fobs anywhere near the LMAP. The magnets in the LMAP can and will wreak havoc on your devices if they make contact with the pouch or plate. Don’t repeat my mistakes. It’s safer to keep those devices on the opposite side of your body entirely. If the LMAP is in a bag, keep electronics in a separate bag.
  • You probably shouldn't take this thing through a metal detector.
  • If you have trouble with the excess webbing flapping around while you’re wearing the LMAP, you can pin it to itself with large paperclips.
  • Feel free to make enhancements or changes to the design! I’m always looking for feedback and this is only the Mk. III LMAP. I intend to keep upgrading this and apply the concepts to a backpack rig for larger blasters.