When me and my friends where shooting a biking film this spring, (check it out here at the end of the summer), we had a problem keeping the camera steady and in focus even when we were moving quickly on uneven ground. This was the inspiration behind this project. The Rope Slider Cam helps to keep the camera steady and moving in a straight line - really useful for dolly like shots.

In this Instructable, I will show you how to make an easy Rope Slider Cam for under ten dollars. It will work with any camera that has a tripod mount (or use an adhesive GoPro mount instead of a screw when you are mounting the camera).

Step 1: Bill of Materials and Tools:

Bill of Materials

bolt and nut - 3/8 inch diameter 2.5" length
threaded bar 1 inch long 1/4 inch diameter 20 per inch threads (or GoPro adhesive mount)
plastic washer from dental floss (Johnsons and Johnsons brand)
adhesive back 1/4" foam
various pieces of scrap wood
two washers - 3/8 - 1/2 inch diameter hole
rope - longer than the distance you want to film plus 2 meters for tying off (thinner rope slides easier)

Tools:

saw (band saw, chop saw or hand saw)
drill and bits
clamps
screwdriver
chisel

Step 2: Cutting the Big Piece of Wood

This step is fairly straight forward. You can use a band saw, a chop saw, or even a hand saw to cut your wood, its up to you and what you have access to.

Cut your first piece of wood to the following dimensions: 4 1/4" x 3 1/4" x 1 1/4"

Step 3: Drilling the Small Pieces of Wood

Next you need to drill the holes for the two smaller pieces of wood, as show in the diagram (you will cut them to length in a later step).

Use a bit that is slightly larger than your bolt diameter.

Step 4: Cutting the Small Piece of Wood

Cut the wood with your preferred method, such as a band saw, chop saw or hand saw.

You should now have two small pieces of wood, each 2 1/2" long, with the holes you drilled in the previous step centered lengthwise on the blocks (see photo).

Step 5: Drilling the Small Piece of Wood (again)

Drill the small piece of wood again, this time drill your holes from the bottom. The holes should be 1 1/2" apart and centered on both the x and y axis. These holes are for the screws that connect the small and big pieces of wood, both to position them and so they don't split the wood.

Step 6: Drilling and Chiseling the Large Piece of Wood

Take your large piece of wood, and chisel out a small channel down the middle of the block lengthwise (photo). The channel should be a 1/4" deep and 3/4" wide. Assuming that you are using a two by four, the edges of the channel will be 1 1/4" from the outside edges of your wood. The channel is so that the rope doesn't catch, and has more space to move.

Step 7: Drilling More Holes

Next you need to drill a couple more holes in your large piece of wood, as marked in the diagram (these are for attaching the smaller pieces of wood).

And finally, add a small hole, dead center on the opposite side of the chiseled channel, for mounting the camera. It should have a 1/4" diameter.

Step 8: Putting It Together

Put the three pieces of wood together

Here is how I put it together:

Screw in four screws from the bottom of the large piece of wood, keep screwing them until they almost stick into your workbench (you want the points just sticking out).
Next, hold one of the small pieces of wood against your large piece, the holes should line up easily if you have the points of the screws sticking out.
Drill in the screws.
Repeat on the other side.

Step 9: Making the Pulley Spinner Thingie

Inside the dental floss box, if you have the Johnsons and Johnsons brand, is a little yellow washer that once had the dental floss wrapped around it.

Remove the yellow washer and hot glue the metal washers to each side.

Step 10: Putting the Pulley Assembly Together

Put the bolt through one of the smaller pieces of wood, then through the pulley turney thingie that you made in the last step, and finally through the other small piece of wood. Thread on the nut so its just tight.

Step 11: Mount the Camera

Next you will insert the camera bolt. If you want to make this a GoPro slider cam, just put on the GoPro adhesive mount and voila! you're done. Otherwise, take your threaded rod and use a file to round the top off a little bit. Then insert the rod into the hole from the bottom. The bolt should sticking out of the hole, into the channel by about a 1/2". Hot glue it in place.

Next, take a piece of 1/4" adhesive backed foam and use a hot screwdriver to make a hole in it and stick it on the bottom of the slider with the bolt going through the hole. If your adhesive foam is not wide enough, you can use a piece on each side (this is to protect the camera from being scratched).

Screw on the camera.

Step 12: Ready to Shoot!

On set. Attach one end of your rope to a stationary object (like a tree), slide the other end of the rope under the pulley and out the other side. Stretch the rope out along the path you want to film, and tie it to another stationary object using a truckers hitch to tension your rope (check out schneidp20's instructable here for how to).

Slide the camera along the rope with your hand, experimenting with your technique it to see what works best.

Go shoot some stuff!