Thanks to Earl Thorbrandr for the tip on using carpet tape.
These instructions should also work for single handed weapons, but the collar of foam is overkill for the "low profile" tips currently allowed on broad swords.

Start with a square-cut pole and a collar of foam approximately 4 inches long and barely wide enough to wrap the pole. Beer koozie optional.
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Stick it on the end.
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Arrange it so about 1 7/8 inches of it extend beyond the end of the pole.
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Tape it closed around the pole. You're done! (Just kidding.)
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Check that the outside diameter is 2 inches, or very close to that.
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take an approximately 1 inch strip of foam, about 10 inches long.
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Roll it up like a danish.
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Stick it in your tip.
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Do it again with a second strip-danish.
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Now the collar is full of rolled foam strips.
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Tape it lengthwise from tip down to the shaft plus about 4 inches. Be careful not to pull the tip off line from the shaft.
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Start your tape strips evenly at the tip and pull back toward the shaft evenly with both halves of the tape.
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Cover the tip completely, then tighten it down with a wind around the base of the tip. Notice this is fiber tape.
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Check the head for minimum diameter.
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Now we switch to carpet tape. Notice the fibers run two directions. Though we don't need double stick tape, that's what this is. We need the bi-directional fibers.
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Place a third wrap overlapping the second and extending down over the shaft.
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place another wrap of carpet tape slightly overlapping the first
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peel back the tape's backing.
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Starting at the tip, apply one tight wrap of carpet tape.
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cover it with your favorite color and type of tape. I like black athletic tape, because it is harder for the target to see, and the texture tends to stick to the target.
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But be aware this is not a durable as plastic tapes.
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