Fixing a hinge

I had to rebore holes in this object and I’m unable to cleanup the old holes. I’d rather not remake half the hinge. Is there some simple way to clean up the surface?

Hinge.3dm (264.6 KB)

1.dupEdge on the hole / and dupBorder on the large surface
2.untrim on the large surface
3.then trim with the curve generated in step 1

1.ExtractSrf all the mess and delete both the new hole cylinder and the nasty patch.

2.DeleteHole the 6 holes, three on each side.

3.Make new holes


But it’s better to generally want to remove the old holes before putting in new ones. Use DeleteHole for that.


I used to do
1)part-selection using command+shift+RMB to select the cylindrical surface
2)delete them
4)wirecut holes


  1. DeleteHole
  2. wirecut new holes
    seems much faster… I always forget deletehole, movehole and those hole commands…

I would have realized this object without using boolean (for the main body) because then there are problems when you go to make corrections. Such as delete hole only works with the center hole that is NOT self-intersecting. After eliminating the holes fail the boolean, also cuts fails surfaces. My approach would be to create more surfaces. I have the impression that here were used extrusions, and boolean.
To remedy without redoing everything, I exploded the object and cut the problem areas, so I could use the boolean to get new holes. Hinge.3dm (328.7 KB)

Well, looking at the model, I would do the following:

  1. DivideAlongCreases SplitAtTangents=Yes SplitAtKinks=Yes
    This is because you have composite G1 surfaces (composed of merged flat planes and cylinders) and those often cause problems.

  2. ExtractSrf the two main planar faces with the holes in them and delete. The hole inside surfaces are left hanging, delete those also.

  3. Cap to close the whole thing automatically and cleanly.

  4. Remake the holes with your choice of MakeHole or Extrude/BooleanDifference

This simply emphasizes the importance of starting with clean/correct geometry.


Hi Mitch.
Your solution is cleaner and better than the one I suggested. I was not able to use the cap command but I used the command “cancel cut” on two extracted surfaces.
edit: maybe just my problem of language comprehension ^^. Eliminating two major surfaces extracted pututo I use the cap command. Comprehension.

You can also select subobjects with ctrl+Shift , delete, untrim , and remake booelan.

Thanks for all the help folks. I found ricardo’s and cyver’s approach nice and succinct. That delete hole command is a gem. Mitch, you’re of course right about starting out with less than perfect construction, but in this case I just wanted to get a minor bit out of the way.