How do you convince your son to comb his hair? You put his name on a comb.
I was originally inspired by the comb by Daniel Martinez, but after trying it I decided to start over from scratch so I could include ergonomic smoothing into the parameters and modules from the beginning. Additionally I wanted to start over so I could more cleanly integrate a calculated head-shape curvature to the ends of the teeth, while still responding properly to parameterized sizing of the comb. I also made use of the new integrated OpenSCAD (version 15.03 and higher) text writing features for the personalized label.
The final result is a fairly comfortable comb to hold. At that thinness, PLA gives just enough flex to work okay for this purpose. It might be interesting to try a variety of slightly more flexible plastics on this design, but I don't have them on hand at the moment. If you try some please post a note in the comments or as a make showing the result.
Note: The OpenSCAD script can take a while to render. There are a lot of high polygon minkowski sums used to generate the smooth ergonomically friendly shapes to everything in the design. Every attempt I made to reduce this resulted in polygonal textures in the print that are discernible to touch. This results in about 24 minutes to render on my current system, but may vary on yours. I figure this is worth it to get the ideal shape before printing. If you don't care about personalized text, I've included an stl file with no words.
Update 2016-08-07: My son pointed out that the corners of the original design were a little sharp due to the flattened sphere I used to generate the ends of the teeth, so I redid the teeth with a spherical tip approached at a parameterized angle. (This update corresponds to the v2 files, shown in the cover photo and the first two rendered stl photos after it.) The small spherical tip at the end of the comb's teeth also facilitates better parting of the hair. Also, if you can, I recommend printing this in PETG as the slight flexibility makes it a very nice material for this.
Infill does not matter much for this, nor is it very resolution sensitive. What IS important is that the teeth are very long and thin, and if they warp during this print it will ruin it. I recommend laying some fresh adhesive (glue stick is great) right where the ends of the teeth are going to print. This will keep them in place.
Depending on your plastic and printer settings, some stringing might occur between the teeth. A small putty knife works well for removing these without disrupting the teeth.