A few years ago, my Nordic Track treadmill broke. What I call the elevation nut broke, the lugs holding the nut which a large acme screw rotated through sheared the nut in half and made the treadmill unusable.
Upon inspection, I found that the stock nut was made out of plastic. A single point of failure likely designed to break giving the amazing treadmill a short lifespan. No matter, using Fusion 360 and leveraging a McMaster Carr CAD file, and I 3D printed a prototype in an attempt to remedy the problem.
The attempt worked, mostly, and I once again had a somewhat working treadmill. Upon startup the treadmill did a built-in test. It traversed to the highest elevation setting then back down to the lowest. When it reached zero elevation however, the nut gave an audible crack, but held firm. I knew I wouldn’t be able to change the elevation again given the cracked nut, but I could use it in its current position.
*Updated 11 June 2022 with 7/8″ threaded Version.
A Permanent Solution
Following this partial success, I decided to make a permanent solution. I ordered a cast iron nut from McMaster Carr and milled a new elevation nut using a lathe and a vertical mill. On the lathe I faced the nut to the desired length, then using the vertical mill I drilled two holes to match the lugs on the treadmill.
The result was perfect and I now have a treadmill that will hopefully last another 10 years. I suppose Nordic Track created the treadmill with a bit of designed obsolescence, but in doing so they gave me an opportunity to have fun fixing it.
