My arm was tired of shaking my paint, especially since most cans call for one minute of shaking. So... I had to make this shaker. It's made from what was on hand, so mostly wood and a few bits of hardware.

Step 1: Can Holder

First, we'll make the can holder.
Draw around the bottom of your paint can, and cut out two identical saddles. I used 3/4" plywood for all the parts.
Then, cut out the base. Mine was five inches wide by three and a half inches, with a tab off the side for the connecting rod.
In the exact center, I drilled a hole to a close fit on my pivot bolt. I had a 5/16 bolt,so that's what I drilled. If you have a drill press, this would be a good time to use it. a nice square hole will insure that it doesn't wobble.
Now, glue and screw the saddles onto the base. I recommend pre-drilling since I'm screwing into the edge of the plywood, and I don't want to split it.
Last, we need to attach a strap to hold the paint can in place. Get yourself a piece of plumbers strap. and screw one end to the flat side of the base. Lay your can in the saddle, wrap the strap around it then mark and drill a 1/4" hole for a bolt to draw it up. Now with a 1/4" carriage bolt, fender washer, and wingnut, you can snug the can down.

Step 2: The Crank

For the crank, I used a disc of plywood mounted on a long carriage bolt.
I cut a disk about 2 1/2" in diameter. this is a little bigger than you really need, but it allows some adjustment.
Drill a hole in the center to fit the bolt snugly. then countersink to fit the nut flush.
You'll need to use a longer bolt than you would need so that the smooth unthreaded part is long enough. I used a 3/8 by about 12" carriage bolt, since that's what I had.
Cut the head off the bolt. screw a nut all the way up to the end of the threads, then install the disc. screw the other nut on and into the countersink. Now cut off all the rest of the threaded part so nothing sticks out of that side of the disc.
After this I took the bolt out and glued it into the disc with J.B. Weld. tighten the nuts before the glue dries.

Step 3: The Base.

For the base, I used a piece of 2x6 about 16" long.
Round the top corners of the 2x6
Decide where you want the components and drill a hole for each shaft. I made mine about 1 1/2 inches from the top edge Again use the drill press for a nice hole square to the face of the board. Make these a nice snug hole.
Now, from the top edge of the base, drill two small oil holes. I countersunk these about 1/4" for a funnel like effect.
Now glue and screw this whole thing onto a piece of 3/4" plywood about 8"x16" for the base of the base. I held it about 1 1/2" away from one edge.

Step 4: Assemble

Now to put the component's on the base.
First find your bolt to mount the can holder. It needs to have an unthreaded part about 1 1/2" long. You may have to use a longer bolt to get this length and then cut off the extra.
Put a flat washer on this bolt, slide it into the appropriate hole in the base,then another flat washer and nut. draw the nut up to snug, but let the bolt still turn easily in the hole.
Next put the can holder on the bolt, another nut and draw it up tight. You want it tight on the paint holder, and free in the base, so the whole thing will pivot smoothly.
Now put a flat washer on the shaft of the crank and slip it into the other hole in the base.
To finish, Make a connecting rod. cut a piece of wood to fit between the ear on the can holder and the crank. Mine is curve because, as it worked out, a straight one interfered slightly. I pre-drilled this and attached attached it with one screw on each end. Probably this will need to be improved later.

Step 5: Try It

Now all that's needed is to put a squirt of oil in each oil hole,
Mount the paint can,
and chuck the crank shaft into your cordless drill.
Squeeze the trigger and shake it baby shake it!!!
Actually, you might want to turn it over by hand first to make sure nothing interferes, then and after spinning it, it might be neccesary to adjust the position of the connecting rod in relation to the pivots to get the action you want.
check out the video @
http://s61.photobucket.com/albums/h54/Heathbar64/?action=view&current=paintshaker024.flv

I'm not sure why but this is actually shaking much faster that it appears in the video.