I have an issue with open surface in power tool object when rendering in TFP.
In the image attached, the top image is what is rendered. The 2 lower images are from the power tool which one shows the item to be rendered closed. The settings on both compomets are closed and capped. The triangle is fine, but the arc shows open ends.
This is an old bug and the programmers were notified.
Try this => unzip the object attached => go to your program => File => Import => Punch Custom Workshop Object => open the object with the 3D Custom Workshop Power Tool => Edit the dimensions as necessary.
Hope this helps :)