Tweet
Is there a rule of thumb setting up the space between the propulsor cone and the propulsor? There also seems to be straightening blades, attached to the cone, directly behind the propulsor on the actual subs but it is well hidden...
-
-
Who is John Galt? -
David,
please would you explain to the knuckle dragging person I am in simple language what #1 means?
oh heck might as well include #2 too!
peace,
tomIf you can cut, drill, saw, hit things and swear a lot, you're well on the way to building a working model sub.Comment
-
I use graph-paper to do this.
1. You work out, in square inches, the area of the circle a propeller describes -- the diameter is blade-tip to blade-tip. Subtract the area of the hub.
you draw the profile of one blade within that circle and determine its area. Multiply that number by the number of blades. You now have total blade area. work out the ratio (percentage of blade area to area of the circle). Alter the blade area to achieve a total blade area to be within 60-75% of the disc, less the hub.
2. Pitch is a linear measurement. The axial distance a proper advances in on revolution through a non-slip medium. A constant pitch propeller is one where each radius point along the span of the blade assumes an angle that will produce the same pitch as all other radius points along the length of the blade. If the diameter of the propeller is 3.5", then the pitch should be 3.5". Pitch is not a measurement of angle, it is a measurement of propeller advance in one revolution.Who is John Galt?Comment
-
Thank you, I am seeing the spark of light!If you can cut, drill, saw, hit things and swear a lot, you're well on the way to building a working model sub.Comment
Comment