« Reply #2 on: February 10, 2009, 05:51:16 PM »
I like to use "green gardners tape"...that green vinyl tape that folks use to tie young trees to upright poles, branches, vines...you've probably seen it. I use a "hollow punch set" to make the inside and outside diameter. You can use a multitude of materials...plastic from lids, aluminum from soda cans, thin sheet metal...to name a few. Thinner is better so you can work with layers...add some shim or take some away until optimum velocity is obtained. Get some silicone oring grease and thinly lube the seal and shims too.

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