3D printing overpronation insoles

Some years ago I started getting trouble with pain during running - I found out after some checks with doctors and orthopedics that this was because of overpronation - especially an issue with my left foot.

So after spending serious amounts of bucks I got some special soles made by my orthopedic - and this helped a lot. But these soles get worn out too, so thats why I came up with the idea to make it myself. 

The first thing I did was going online and finding some flexible fillament for my 3D printer. I started looking at Colorfabb since I have used them before, but found that their flexible fillament needed (at least on paper) a heated bed. My cheap Finder does not have this so I looked further and found Ninjaflex. 

I booted up Onshape and made a simple sketch of a sole. I have used variables for width, length and pronation degree, so it should be fairly easy to adjust the CAD drawing for your own needs.  You can find the sole here - if you have some brilliant ideas on how to improve the design, be a gentleman/woman and let me know :D 

I made a quick prototype with the lowest settings on my printer. I struggled a bit getting it to print at all in the beginning - I have never worked with flexible fillament before. In the end I made it work at 230 degrees, 40% infill and slow speed. I also made sure to not let the extruder pull the fillament as this gave me issues - during the print I ensured to pull out fillament so the extruder did not need to use any force in the process.

After my print I installed the heal in my shoes and it is no doubt that this will work. I have printed the prototype at the lowest quality and with 40% infill. I think a new version will be printed with 100% infill and higher quality. Some quick measures shows me that the cost of such an inlay would be around 1-2USD. My last inlay from an orthopedist costed 150-180USD (plus the consultancy of about the same so together around 300+ USD). 

The video below shows how flexible the part is - I am amazed by the NinjaFlex product and it opens up a new world of possibilities for my printer. Making insoles for medial issues is but one of them :D
Please note that this was printed at the worst quality to reduce time - it is indeed a proto!


Popular Posts