A better way to accurately add cuts to this face?

This is likely a simple question to answer, but I’m still new to blender and while I found out -A- way to do this, I’m not convinced it was the best way lol.

So I am making a fan vent, which could probably have been done in Fusion much easier, but I wanted to do it in blender as something to learn on.

The part I’m at here (I included a picture) I wanted to add two cuts on the narrow face, so that I could extrude a small tab out which I could make a screw-hole in. But the problem I had, was that I wanted this tab to be central (and 6mm wide), which means that each cut needed to be 3mm from the centre of the face.

However, the ‘loop cut’ tool would default to the very centre of the face, and I would then have to move it by hand in one direction… which was fine. But then when I do the second loop cut, it defaults to the centre -of the new face-, which is nowhere near where I needed it. And so its hard to accurately move it to the right location.

What I ended up doing, was selecting the two long edges, and subdividing into 22 sections. This put the right block in the centre. I then had to select the unwanted 21 faces, and dissolve those faces.

I did try to mirror the object, and then do a loop cut. But while the object was properly mirrored (X-axis, X-bisect), it seemed to ignore any loop cuts I made for some reason. Not sure why.

Hopefully this made sense. As I say, I’ve ended up with the right result, but I’m sure I did it the long-winded way, and I’d rather know the RIGHT way!

Heres the picture. The arrow points to the new face I made, which was my goal.

You can scroll the mouse wheel during the loop cut operation to add multiple equidistant loop cuts. Would that be helpful?

Press ctrl+B with the single center edge loop selected.

I did notice this, but to get the right placements I’d still have to make loads of cuts, so it’s no different to subdividing. Except that loop cuts don’t only effect the face I have selected, they also go onto adjacent faces, making a big mess. (I do wonder if there is a way to make a loop cut only effect the selected face?)

Interesting, I’ll try that and see what it does thanks :slight_smile:

Oh I see, it makes a ‘bevel’, but it’s a flat bevel with a weird triangle profile on the side face… it does work though! I’ll try and remember this one, thanks.

Can you create a new cube and change its width to 6 mm and add a boolean modifier to your original object? That would subtract the new object from the base object and you could easily position it with translations.

I gave it a try… and used the bevel on the edge loop and it works but this is how I did it…I first added a plane>scaled it a bit>extruded to z…then in edge selection selected the edges on two opposite sides…added a single edge loop…then repeated for the other 2 sides… then with cursor in center of object… selected all 4 center edge loops, and added offset bevel with edges of 1 etc.

that gives you this,


Which I then selected the faces made one by one and extruded them …
I just added the extra bevels around the extrusion for the fun of it…

I think this is essentially what Grim said, but a slightly different workflow, and yeh it would seem to work :slight_smile:

@clacker I think that would work too. Originally I was going to create a separate object the right shape/size and then move it and merge it with the original object… but I figured there were other more elegant ways to do things, and I’m trying to learn more options in blender :slight_smile:

I’ll add this here in case any of you come back and might know the answer to this problem too.
I’m trying to merge these faces (video link below to show what I mean) so they become one face, as at the moment they seem to be two separate faces that overlap into each other.
Following a guide on the blender stack, I originally (when I made this object out of multiple smaller objects) used ctrl-J to ‘join’ them, thinking this was how you… joined things! But I now realise that all that does is group them in the Object View, but in the Edit mode they are still separate. But now that they’re being ‘seen’ as one object in Object view, I cant use boolean to actually merge them together into a single mesh.

I have tried my other usual fallback of ‘dissolve faces’ but that doesn’t seem to work either, I assume because they aren’t actually connected faces.

I figured there would be an un-group option somewhere (un-join?) but I can’t find it and googling for it doesn’t come up with anything that actually helps.

My final fallback is to just make it again from scratch, and then join the objects with boolean-union instead of the unhelpful join thing. Seems odd to have a ‘group’ command that doesn’t also have an ‘ungroup’.

Try this.

  1. make sure your units are set to mm

  2. zoom in close on your working area, so that you can see the individual mm squares on the grid.

  3. visually line up the edge with the closest square.

  4. constrain the transform axis (press x,y,or,z while translating) and press Ctl to snap to increments until you get to 3mm.

This might be the same workflow you used with a minor optimization… And since your visually lining it up it won’t be exact.

Also, what your doing here is joining the meshes so that its part of one mesh, to undo that: Edit Mode --> Hover over the piece that you want to unjoin or separate --> L to select linked face,vertices, edges --> P --> Selection to separate by selection. Just a thought, while in edit mode you can add entirely new objects with shift A so you can work on a separate piece from scratch, maybe hiding the parts you don’t want in the way with H, and Alt H to unhide. You can use the same operation hovering over the part and press L or selecting one of the verts, faces, edges and pressing Ctl L, and then hiding it by pressing H. As long as they are not connected yet. Joining meshes wont cut anything or make a hole in the mesh though, Boolean will do that and it seems that’s what you after.

Use the “separate by loose parts” option in the ungroup dialogue… P key I think.

I think there was a way to join multiple objects without using booleans for every single object, but I don’t rightly recall. Meaning that right now boolean union would be the only way I can suggest.

As for the previous conondrum - you can specify the bevel offset. I’m not sure how precise it is so I won’t say it would go straight to 6mm. However, there is one more way after you bisect the face through the middle… let me start from scratch:

You have a face.
Slap your face on the keyboard.
Now make a 4 vertex face
Knife tool, hold CTRL to place cut points on middle of edges
Bevel tool
CTRL-R to loop cut in middle of new edges or use Knife as before
G+G to edge slide each edge to middle, then G+G to slide for a certain percentage between the adjacent vertices. It’s not the best way but it’s possible. Hopefully there will be an absolute option in the vertex sliding method.

By the way, GG is edge slide, SHIFT-V is vertex slide. Apparently there is a difference between them.

You shouldn’t get those results if you selected the edge loops before beveling.

Another sometimes useful technique is this:

Select an edge loop, then press Control + Shift + R and drag the pointer to place an edge loop at both sides.

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Update… I was thinking about it as I closed down last PM and realized I just did it the long-about way…select the object> go to edit mode> select all edges> add the loops> select just the short side loops> add bevel…or at this point you could add a bevel modifier if so inclined, and keep it non-destructive…

Oh yes I like this much better…and kills off the n-gon to boot!

Already tried ‘separate by loose parts’, but it does nothing. The parts are all still grouped together in the object view.

This seems to have worked, thanks!

Thats great.