This is the page that I placed all of the other stuff I had no idea what to do with. You will also find updated modifications and information pertaining to the SpudZooka.
August 11, 1999
Sometimes the potato doesn't seem to have the power it should. I believe this to be a result of the chamber not filling to the maximum pressure that is being applied. This may be caused due to the close machining of the large washer that comes in the kits. The original washers I cut by hand, and there is no way possible to match the quality of the stamped washers therefore, the stamped washers I believe seal off the air flow while charging the outer chamber. Actually I believe the thin rubber gasket gets pinched between the washer and the chamber walls.
One way around this was to drill holes through the thin gasket and the metal washer, but NOT THE THICK GASKET. This acts like a check valve and will allow faster charging of the main chamber through the holes rather than trying to squeeze the air out around the poor sealing of the gasket edges.
Here is a detailed drawing of the holes that are to be placed in the diaphragm.
Another good thing after doing this modification would be to apply a thin film of silicon to "glue" the washer to the thin gasket. (I use silicon sealant because it holds to everything and is easily obtainable. It's the stuff you seal windows with.) With the holes in the thin gasket, it may tend to fold. If this happens the diaphragm assembly may get cocked and won't seal properly.
As soon as I get a picture, I'll post it here. Sometime in the future, this information will be incorporated into the SpudZooka plans.
August 1, 1999
Here are some formulas that I am using to design larger cannons. They help to give barrel to outer chamber air volume ratios. They give other useless information like the pressure placed on the cleanout plug. Using a spreadsheet really makes it easy to try different numbers out. it is a must if you are going to design your own cannons. Download them for what they are worth.
Spud Calculations (Excel 95).xls
Spud Calculations (Excel 97).xls
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