If the tilt mechanism on the blinds stops working this could be the solution.
The plastic part of the tilt mechanism that the cord winds around can break easily. In my case the axel from the metal part had rounded out the tube in the plastic reel and was just spinning freely.
I modeled this in tinker cad after taking a few measurements. Installed and worked perfectly on my blinds.
Print flat with supports, any material, I used white no-name PLA, I don't think any other settings are that important. It's a simple print.
The author marked this model as their own original creation.