When I did mine, I realized that every tool almost has a 4" collection hood. This is because when DC's were introduced to the home WW'er, they were 4" to begin with and the after thought of dust hoods were also made
4" to match the DC input. When I changed the size of the collection hoods on my tools there was no affect on the dust collection process.
Here's a note. To start with, I was using a 4" line into the collection hood of my planer which went from 4" round to a 4" square. This meant that there was 12.56 sq in. area where the air from the dust collector was coming from was being drawn from a 16 sq in area hood. This meant that before anything could be done, there was a 25% drop in the efficiency of the DC dust collection when it was hooked up because of the dust hood design. When a 2.5 inch line was made as the DC line there was a 7.85 sq in suction area from the same 16 sq in. hood, which made a less than a 50% loss. When the hood was redesigned to a 8.2 sq in suction area, the dust from the new hood rushes from the planner as fast as if you were picking the dust from the floor. Thus the hoods of all tools were redesigned to be a better comparison from the vacuum line to the hood. Now, even a shop vac would work well on my planner.
-- Woody
Check out my Web Page at:
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you will find:
******** How My Shop Works
******** 5-21-03
- * * Build a DC Separator Can Lid. 1-14-03
- * * DC Relay Box Building Plans. 1-14-03
- * * The Bad Air Your Breath Everyday.1-14-03
- * * What is a Real Woodworker? 2-8-03
- * * Murphy's Woodworking Definitions. 2-8-03
- * * Murphy's Woodworking Laws. 4-6-03
- * * What is the true meaning of life? 1-14-03
- * * Woodworker Shop Signs. 2-8-03