Solved Print does not match model

Hello all,
So I was trying to print out a part in two halves, with each half being essentially an arch. Now, when combined, the two arches are supposed to form a ring. However, I found that it's not printing it correctly. Instead of forming a ring with a perfect circle in the center as it should, the internal circle is coming out as an oval. I tried printing it on both Cura and MC, so I doubt it's the slicing software. I also had several people check my model to make sure that its a perfect circle, so I doubt that it's my model either. Any advice would be appreciated!

 

Oh, sorry my bad. It's just standard white PLA. Also, it's not warped. A few layers just vanished from the slicing software or something

 

Ok, done. It came out the exact same.

 

I would definitely change the orientation of the print, to eliminate the bridging at the bottom of the arch. Print the way you have the picture taken and it will fix some issues.

 

Done. It fixed many of my issues for now, but it created a few new ones, such as the holes coming out the wrong size. I can just drill those out however, so I think I should be good for now. Its just kind of worrying that my printer can be so inaccurate all of a sudden.

 

Not sure if MatterControl or Cura have this setting: "Horizontal Size Compensation?" But in S3D, I printed a dowel (OD=5mm) and a cylinder (ID=5mm) while adjusting this setting until they were a perfect fit for each other.

I have seen some people scale the model a certain percentage to get it to come out correct, but I don't prefer this method.

Lots of things could actually affect the size of the inside diameter though. Speed, Acceleration, Over/Under-Extrusion, etc. Changing some of these will definitely bring the accuracy up, if you have not modified them already. Most of these settings are changed within the Firmware though.