Thanks for all of the help everyone. I'll look into this some more. I don't know why my circle would not trim. Both points should have been on the circle. But since you got it to work, that gives me hope. As far as the trailing edge radius being very small unfortunately I can't do anything about that. That is a NACA 65A009 airfoil. I don't specify what it should look like. That is just what it looks like. I can do it in Rhino. I have to change all the default settings to do it though. I wan't to try the suggestion earlier of scaling the model way up then way down and see how that goes. I joined the entire airfoil surface together but it still made the model with errors. I hadn't mentioned it previously. But given everything everyone has said it has to be a tolerancing and dimensioning thing. I'll play around more since now I know at least in theory what I'm trying to do can work. I have the Rhino model as a part of the download to my program on my SourceForge site. I tried to upload the Rhino model here but it was too big.

The rhino model is in the examples/rhino folder within the prop_design.zip file. The reason I was interested in trying MoI is that you do have to fiddle with the Rhino settings a lot and I don't think everyone would know to do that. Also rhino can't do the fillets when you try to blend the blade to a hub. So you'd have to take it into solidworks or something. I don't think everyone has the money to do that. So ideally a low cost, easy to use, program that you can get a detailed fixed pitch aircraft propeller is what I'm looking for. Not for me, but for people that would use my program. I can't whole heartedly recommend rhino as I know it has limitations. Moreover, you can only get so far with it before you have to abandon it for an even more expensive program.

Edit; I have since closed my SourceForge project. You can find my MoI example here; http://propdesign.weebly.com/.