Pumps
You could probably build a tube pretty easily if you're not afraid of hand tools. I made my tubes out of good acrylic tubing. The tube is 1/8" thick so a 2" OD is 1.75" ID. The acrylic was about 18 bucks for 6' lenghs and the caps I got from the plumbing section in Home Depot or Lowes for 3 or 4 dollars. The brass npt to 1/8 niple is about a buck and the you're almost there. Go to a pet store and get a one way valve for 2-3 bucks and you're set. This is what I did and it works great - I just suck on the end of the tube and create enough vacuum that way - or you can use a hand pump - either works. If you're careful, you can heat the end with a heat gun and flare it - this gives it a comfortable fit against your pelvis. I've made 2", 2.25", and 2.5" tubes this way.
