Sinusoidal Curve?

[Plappy]

Anyone have any insights as to how to go about drawing a curve (presumably sinusoidal) with which to create a surface on? What surface do I create? I'm in the process of trying to duplicate a propellor blade for a miniature boat. I just need the process if anyone knows. If I knew what to ask, I'd probably know how to make it, so my question may seem a little wierd.

[BernieT]

Welcome to the forum !!

 

I think I would draw 3 or 4 cross-sections of your blade (in the correct place and orientation) and then do a lofted surface between. Maybe a network surface to finish the blade end.

 

Alternatively, draw the cross-sections and a spline of the parting line and use network surface to make the top and bottom surfaces.

 

I don't see a need for a sine curve.

 

Good luck !!

 

Maybe try some google searching of 'boat props' for more ideas.

 

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[Plappy]

Thanks! I'll try your suggestions. What i also did was make an automatic spline, using points (looking down on the prop) at 0 degrees, then at the OD of the prop 1/2 way up, then at 120 degrees at the top of the prop. Looks pretty good, but I don't know how to create the surface.

[mpeterson]

I have tried to figure out how to figure out cross sections of wings/propellers. If you have any sites that talk about it I would appreciate it if you shared.

 

I agree Loft surfaces would be the way to go in this situation.

 

With using Loft surfaces, make sure when you pick your chains in a row, your start point and direction is the same point. Loft "Syncs" the chain which forms the surfaces.

 

If you use Help in Mastercam you can search the different Surface functions, I recall it kind of explains the strategy.

 

Mike in MN

[Plappy]

Thanks, Mike in Mn. I'll get back to this little project later today. Its one of those things that isn't really necessary, but puts your brain on "search mode" and you don't stop till you get it. I'll let you and the forum know how it works out.

[Plappy]

Well, here goes. Thanks to Bernie T, I got on the right track. I made the surface of the hub. Defined the cross sections of the prop at .200 intervals from the hub out to the trailing edge. Projected the first onto the hub surface, then attached (or placed) the following contours working my way out. I rotated each contour as necessary to follow the pitch as they got out to the edge of the prop, and finally connected them all to achieve geometry to create lofted surfaces. It needs a little work, but its basically there. I plan to just copy the blade twice at 120 degree intervals and that should do it.

Do not try this at home....

[BernieT]

 

 

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[Mike S @ S4A]

not exactly what you asked for, but

 

http://www.ae.uiuc.edu/m-selig/ads.html

 

Airfoil profiles as data files

[BernieT]

Great site Mike !!

 

Neat part is you can pick an airfoil, click on it and it opens in Notebook, now delete the heading and save the file as a .txt file.

 

Mastercam can 'Convert - Read' an ASCII file - select the airfoil txt file - read it in as points and 'voila' :