I’ve got to admit, I had a bit of difficulty getting a propeller that was even recognizable. This challenge may be more difficult than it looks. Consumer product, “artsy surfacing”, is easy enough, because no one knows if you are faking it. There is no such thing as “precision” in that kind of modeling. As long as it looks good, you’re ok. I’m not trying to put down that kind of work, because I do plenty of it.
The difference with technical surfacing is that you’ve got to satisfy the asthetic sense, but only after you’ve satisfied the math. I didn’t really use any math for this model, but people who do make propellers and other air or fluid foil shapes do need to be technically precise. A recent boat hull project brought some of this to my attention.
So, the challenge is to model a propeller. You can model a plane or boat propeller, or some other type, such as a pump or compressor impeller – any sort of turbomachinery type device will do. I’ll go through each model and make comments based on a few things:
- starting reference data if any
- quality of sketches
- inventiveness in SolidWorks surfacing techniques
- does it actually look like a propeller?
- surprise me
Anyway, my comments may not come immediately, this is a busy week for me. Send in your models to my email address, matt at dezignstuff dot com. I’m really looking forward to this. Technical surfacing is very difficult.
Entry #1 is from Matt Sass. Matt swept an airfoil shape along a straight line, using the “Twist Along Path” option, twisting 60 degrees. Thanks for that entry! The first step is the most courageous. Click the image to download the part. Keep ‘em coming!
Entry #2 is from Garrett Brooks. This is a very nice job. Garret searched the web and found a nice sketch picture, then traced the various profiles and used Derived Sketches to place the sections where they should go, then made a Boundary surface with several guide curves. The ends of the blades are capped off with Fill surfaces. This one is nicely done. You owe it to yourself to download it and check it out.
Entry #3 is from Rick McWilliams. This is another very nicely done model. Rick made a boat propeller instead of a plane prop. Rick used a different technique on this one. Because the blades take up a bigger wrap angle around the prop, it made most sense to lay the lofts out using cylindrical cross sections instead of flat cross sections. The required flat sketches that were wrapped onto cylindrical faces. Then rick lofted through the wrapped edges, and lofted to a point to cap off the blade. Very nicely done. This one is saved in an older version ofSolidWorks. Don’t know which one, but it is at least earlier than 2009.
Entry #4 is also from Rick McWilliams. This is an assembly of a cooling fan. Download Ricks assembly and parts and see how he made the blade.
Entry #5 is from Dave Yeagly. Dave took the simple but effective route with this one. He did a two line loft to get a twisted shape, then trimmed it to get the prop blade shape.
Entry #6 is from Robert Veronneau of Hammerhead Aviation. Robert had a P-51 Mustang propeller blade sitting around the office, and decided to digitize it. It looks like he used DezignWorks with a romer arm. Robert says “The sketches (Splines) have not beed cleaned up yet, so the entire model is a bit rough.” Yeah, looks REALLY rough, Robert. Actually it looks great. Thanks for sending this model!
Entry #7 came from Garrett Brooks. This is a nicely done surface model. Download the model and check it out.
Entry #8 is from Mark Reader. Finished in Solidworks, but done in MoI. Here is what Mark had to say:
Wow, great challenge…… First off, I intended to do this model completely in SW but it became too frustrating and so it was back to MoI. Not trying to be a fanboy or sell it, but it is a fun program to work with. Like Garrett I spent time searching for some drawings but I like the one he found better. My approach was similar to his but I found it difficult to get rid of the waves, dips & bulges I was getting. You can see some in his model too if you look down from the tip of the prop. They’re there, but not that bad compared to what I was getting.
Attached are 2 props done in MoI, brought into SW and rendered. 1 is semi-realistic and the other just for fun. The import into SW wasn’t as clean as it’s been for me before. I got several “extra” surfaces so there was some clean-up needed. I also didn’t pay much attention to size/scale. If time allowed I wanted to work on the wing tips a bit more but…..
Another hack’n’slash attempt, somewhat late and maybe not what you were looking for…
The attached is an eyeballed turbine blade, the airfoil modelled using a boundary surface. The section sketches are derived from a master. What I didn’t know was that you could drag and scale a proportional spline in a derived sketch…. Haven’t explored this any further.
No idea how near realistic it is (not very at a guess).
The last time I attempted to model one of these was using SWX 98+ when I had to try to reconstruct a blade from a drawing (coord sections) to use as a scaled calibration target. This was for a set of tip clearance probes a former employer used to make. It was completely impossible…
Keep up the good work,