Hi Sean, so your little dot is not a totally extra thing hanging out there, it's this edge from the top face:


If you zoom in to the top there you can see that edge is some slight distance to the right of the other ends:


However, again this distance is just 0.0000168 units, so it's like some fraction of a flea's eyebrow hair off, and well within tolerance, so it's totally fine.

If I was able to see exactly how you built that area I might be able to suggest some other way of doing it that would make the accuracy even tighter but the current deviation is so small I'd recommend just not worrying about it. It's normal with any kind of CAD model for edges to be off by orders of magnitude more than that, although often times with planar geometry it can be all exactly aligned like you were looking for. It depends on the particular things you're doing though, and it would probably help if your model was a bit bigger, like probably if your model was 10 times larger in size that particular calculation would have still gotten down to 0.0000168 units but then that's another 10 times tighter.

Hope this helps, as best as I can tell your model is totally fine and should print ok.

- Michael

But now I read your message again and you mentioned booleans and extrude not working, can you post an example of those problems? Booleans that have pieces with overlapping surface areas can be sensitive if the overlapping areas are not very tight to each other. It can be a lot easier for a boolean to work if the pieces push through each other a little bit rather than skimming each other.

- Michael

Hello Sean,

maybe check first the angles and decide what you can use to rebuild and use the construcction lines often as possible. Make your lines longer and use trim.

I tried to rebuild it - have a look - I'm not shure if everything is okay for you.

Have a nice day
Karsten

Here is another quick video showing what im talking about using the same file as before. I was having a ton of similar problems a week ago so I rebuilt several parts and I am wondering if something like this was the cause, and if so how can I fix it/prevent it from happening again?

https://www.youtube.com/watch?v=IzfUZ6z_Ig8

I didn't realize the deviations I was stressing over were so small. I have been building with object/straight snap and am concerned that they don't seem to perfectly snap every time, but also realize that at those sizes it doesn't really matter anyway.
I really appreciate all the help. It is awesome that there are people willing to answer questions from people as green as me.

Hi Sean, the best way to get rid of that edge (which again is not really necessary, it should generally be ok to have it such a small distance away it is well within tolerance), would be to do some lower level operations than booleans. I'm not exactly sure why the extrude of that one face doesn't produce any result, but that probably does indeed have something to do with this edge you're worried about - when you extrude a face it is really a batch operation of internally generating a non-attached extrude followed by a boolean union between that extrusion and the main piece. Like I mentioned earlier, booleans between pieces with overlapping surface areas do tend to work better when they are very precise in the overlapping region.

So anyway to remove your pernicious edge ;) try the following process - select the 2 adjoining faces to it, the top and side wall faces and delete them. Now that edge is gone and you can construct a better one to take it's place. You'll do this by using Draw curve > Line, and placing a new line between the 2 corner points, make sure Object Snap is enabled and you see an "End" snap tag show up for each point of the line you place, that way you know the new line is snapped on to ends of those other existing edges.

After your new line is placed, select the new line and the 3 open edges of the top square, and the circle edge in the middle of it. So now you have 5 objects selected, one line curve you just drew, 3 line edges on the main solid, and one circle edge on the main solid. Now run the Construct > Planar command to build a trimmed planar surface through those selected objects. You can now clear the selection and select the line you previously drew and delete it, you don't need it anymore.

Now select the new planar surface you just constructed, and also the main object. Now use Edit > Join to glue those together. Now you need to rebuild the side wall as well, since that's a planar opening bounded on all sides by edges there is a shortcut for doing that, just select the entire object and run Construct > Planar and it will build a surface there and automatically join it. Construct > Planar can be used in 2 different ways, when used with a curve selection it will build an individual planar surface through those curves. When used with a joined surface object that has open edges, it will look for any sequence of unjoined (so-called "naked" edges) in the object and build planar surfaces through those and automatically join it in.

It looks like there may be another couple ones like that around because I'm still seeing that a face extrusion of that vertical side is not behaving well. I tested it by selecting the edges around that face and duplicating them as curves and then going to the Front view and trying to squish it down and seeing "flat" snap engage (see here for a demo of flat snap: http://moi3d.com/forum/index.php?webtag=MOI&msg=3378.4) - the thing is flat snap will only engage if the objects being squished were not already very tightly planar. But if you do want to extrude in that direction it seems to be enough to duplicate the edges, flatten them with flat snap, then extrude those and boolean union that result to the main object.

Hope this helps!

- Michael

But again let me stress - your object should be 3D printable exactly as you currently have it, you do not need to worry about tuning up that edge you're worried about before printing it. I guess if you want to do face extrusions it would help to tune it up though.

- Michael