Portable Slackline

11 feet or 3.3 meters long

Total cost about $40

Build in a few hours

Three 12 foot 2"x4" Pick STRAIGHT ones, use pressure treated if it will be outside a lot (~$12 for non-pressure treated)

3" Deck or Construction Screws, star drive recommended. If it will be outside use deck screws. If you use pressure treated wood use screws rated for pressure treated wood. (~$10)

Tie Down: HAUL-MASTER 3300 Lbs. Capacity 2 In. X 27 Ft. Heavy Duty Ratcheting 1 Pk ($15) https://www.harborfreight.com/automotive/cargo-ti...

Tools

Chop saw or Skilsaw (chop saw preferred)

Drill with star bit

T-Beam

T-Beam top: Cut 4.5" off the end of one 12 foot 2x4

T-Beam bottom: 12 foot 2x4

Towers

The towers are 5 2x4s screwed together, each step is 1" shorter. I left a gap in the ratchet tower, it is not necessary.

2x 5" Top step (Round the edges off one end of each top step, see picture 3. I trimmed the edge off with the saw before cutting it to length for safety.)

2x 6"

2x 7"

2x 8"

2x 9" Base step

Legs and Leg Supports

2x 26" Legs

4x 5" Leg supports

T-Beam

Screw the T-beam top to the T-beam bottom. The T-beam bottom is 2.25" longer on each end to hold the 2" tie down strap. Put a screw every 6" on the end thirds and every 12" in the middle third because the screws on the ends will take more stress. Tip: Hold 1" spacers on each side of the T-beam bottom to align the T-beam top. Slide the spacers along as you drive screws.

Towers

Don't make the towers like mine, I left a gap in one tower for the ratchet which was not necessary and I had to add one more layer than planned so I don't have smooth steps. Make the towers identical. Use 4 to 5 screws on each layer to make a stepped tower. Start with the 9" board and keep going up to the 5" on top.

Legs and Leg Supports

The 5" leg supports are screwed in with one screw. The 26" legs are screwed into the leg supports with 2 screws.

Tie-Down Ratchet End

For the ratchet end unscrew the long bolt holding the strap and put the metal hook loop through the bolt too and tighten the bolt. See pictures. The pictures are of the first 900lb tie down I tried, it wasn't strong enough. Creating the loop with the stronger tie down will be similar.

Tie-Down Non-Ratchet End

Pass the end of the strap through the metal hook loop to make a tight loop. See earlier pictures.

Final Assembly

Place the strap over the towers and start tightening. Test by kneeling in the middle, keep tightening until you no longer touch the wood.

16 Foot Version!?!

16 foot 2x4's are available. If anyone tries one please comment and send pictures. I think the T-Beam would need to be stiffer, perhaps the bottom of the T could be made of 3x 16 foot 2x4's with the middle 2x4 left longer on the ends to hold the tie down strap.