Why Peristaltic Pumps? Peristaltic pumps are great! They require no priming, they can pump uphill, they can pump viscous liquids or fluids that have 'chunks', require no special materials, and can be cleaned/sanitized very easily. In short, they may be the perfect pump for the home brewer! Learn more here http://en.wikipedia.org/wiki/Peristaltic_pump
How Peristaltic Pumps Work? Peristaltic pumps work by squeezing a tube like you might squeeze a tube of toothpaste - except in this case the tube is a 5-foot-long silicone hose, with as much "toothpaste" as can fit in your bucket. This squeezing action is called 'occlusion'. Usually, you get this squeezing force by pressing the tube against the wall of the housing with a roller. The number of rollers in a pump determines how much fluid gets pumped for each pulse, the more rollers, the more pulses per revolution, the less fluid per pulse. All things being equal you get less fluid per revolution with more rollers, but smoother output. More rollers can also reduce the hose life.
Why build your own? As mentioned previously, peristaltic pumps don't require special materials, but there's a serious dearth of manufacturers building for the home market. You can buy little peri pumps for lab use or giant ones for industrial use, but not much in between. So, if you need to pump some wort around, want to water cool your laptop or just want to make a pump you can take with you and power with a drill, then a peristaltic pump may be the answer.
Ready to have a go? Follow along and get pumped up! (har har)
5 ft silicone hose from the local home brew shop - it's 1/2"ID, 3/4"OD IIRC
A block of wood - nothing special, I'm using an offcut from an ikea hack. It's 1 1/2" deep. You could easily use a 2x4 off cut. You may just need to make more cuts. A much larger piece of wood will necessitate a longer bolt, too.
2 large (1" or larger) washers and 2 small (1/2" or so) washers. If you have large fender washers, that will work,too. These act as bushings, so don't skip there
2 1/4" -20 t-nuts
2 1/4" -20 nuts, or 1 nut and one cap nut.
1 1/4"x 3" - 20 bolt
8 #12x 3/4" wood screws
Zipties (what project doesn't need a few zip ties
Tools (again, use what's available to you):
dremel tool or similar with grinding stone and cutting wheel (I really like the reinforced cutting wheels because they are less likely to break apart and poke my eye out)
7/16" drill driver (if for some reason your 1/4" bolt and nuts have a different head size, you'll need a different size set of drives)
tsquare or framing square
circular saw, chop saw, table saw, hand saw, or laser vision