4: sheets of 1/4 inch 4 by 8ply wood
6: sheets of 1/2 inch 4 by 8 ply wood
11: 2 by 4s each 5 ft 11 inches long
2: 2 by 4s at least 5 ft long.
if you want to build a 3 ft half pipe use 3 sheets of 1/2in ply wood. by over lapping the curves.
skill saw or carving saw
table saw circular saw or hand saw
200 - 300 2 inch screws.
a hammer might come in handy.
Step 1: Drawing the Pull In
and a 6 ft board and a few screws
screw the 6 ft board into the ply wood so it looks like my picture.
make sure there is an inch of space on the ply wood between the board.
now for the string
go to the top of the board and measure one inch down from the top and but a screw in to it.
now tie your string onto the screw
and on the other end tie a pencil make sure the pencil is perfectly on the bottom of the ply wood as seen in my picture.
now keep the string pulled taught ,the pencil strait up and go up and down a couple times until you get a nice smooth line. that looks like mine.
now if you're going to use coping or not draw a little notch in the top to put your coping into if you're using a 2 inch tube make the notch 1 1/2 inches each way.
Step 2: Cutting
cut along your line.
pic 2 now go get two more ply wood pieces that have to be 4 by 8 ft. and position them under each other and screw them together. snugly!
pic 3 now cut along the line of the first one you made.
cut slots that would fit your 2/4s an the slopeing part cut a notch every 8 inches or so that should leave you with about 5 slots maybe 6 on the last one where there isn't enough room to cut it downward you need to cut it horizontal.
if you're making the 3 ft half pipe use picture 5
Step 3: 2 by 4s
pic 3 screw them in now.
Step 4: Surfaceing
use the 1/4 inch ply wood and use two layers.
the ply wood will be too long make sure you have about 7 inches hanging off the bottom part. so you can cut it off to make it smoother.
2 cut off whatever happens to hang over the notch that you cut out for the coping and if you aren't using coping cut it off where it comes to the top
to get the ply wood to bend easier you may need to lay it on your drive way grass of patio and spray it with a hose the patio or drive way works the best because it locks the water under it and absorbs it.
Step 5: Copeing
pic 2 this is a more detailed description
Step 6: The Platform
pic 2 get the shape
pic 3 screw it in place