We are attempting to make our own propeller for our 74ft steel sailboat because we came to own an beautiful Hundested controllable pitch propeller hub, but it had no blades and getting Hundested to make them was going to cost an arm and an leg.
@submarineboat Hi Doug- its too easy for me to just buy one--i can get a 36 inch wheel for 400.00 so its cheaper to use that--money for me is tight so going through all the experimentation will cost more than the prop is worth...
@porpoisefathom Slip is 100% when we've run aground. :) Seriously, I remember doing the calculation but don't remember the answer, but it was in the guidelines in Dave Gerr's Propeller Handbook. Rhino and Solidworks would both likely have better tools for this job, but I dont have much experience so I stuck with what I knew. We still need a gear to get the RPM down. Acrylic is nice and stiff and I had it laying around. ...Looking forward to seeing your carbon fiber prop. --Doug
Hey Doug- what are estimating your prop slip at? Is this a, n.u.r.b.s.(non uniform rational basis spline) program? I use rhino--i find it is geared for marine use.
The controllable pitch-I know they are great for running a constant rpm- does it eliminate the need for a gearbox?
May i ask why acrylic? (have you thought of a carbon fiber layup for the prop?) I was going to experiment with carbon fiber props. i was toying with using plaster of paris for the template.
@porpoisefathom Yep $400 is a great price and there is no need for controllable pitch on most boats.
submarineboat 2 months ago
@submarineboat Hi Doug- its too easy for me to just buy one--i can get a 36 inch wheel for 400.00 so its cheaper to use that--money for me is tight so going through all the experimentation will cost more than the prop is worth...
Ill keep u posted- Doug(also)
porpoisefathom 2 months ago
@porpoisefathom Slip is 100% when we've run aground. :) Seriously, I remember doing the calculation but don't remember the answer, but it was in the guidelines in Dave Gerr's Propeller Handbook. Rhino and Solidworks would both likely have better tools for this job, but I dont have much experience so I stuck with what I knew. We still need a gear to get the RPM down. Acrylic is nice and stiff and I had it laying around. ...Looking forward to seeing your carbon fiber prop. --Doug
submarineboat 2 months ago
@KEF791 Thanks Keith
submarineboat 2 months ago
Great vid Doug, real nice views on the screen, I love when learning is intertaining too!
KEF791 2 months ago
Hey Doug- what are estimating your prop slip at? Is this a, n.u.r.b.s.(non uniform rational basis spline) program? I use rhino--i find it is geared for marine use.
The controllable pitch-I know they are great for running a constant rpm- does it eliminate the need for a gearbox?
May i ask why acrylic? (have you thought of a carbon fiber layup for the prop?) I was going to experiment with carbon fiber props. i was toying with using plaster of paris for the template.
porpoisefathom 2 months ago