Full Version: Trying to create a solid body

I have been racking my brain for 3 days trying to get this be a solid body. No matter what I do. I just cant get it and would really like some help on this please.

Attachments:
Drone_v06.3dm

Image Attachments:
4.JPG 

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I imported the model into cad assistant and then exported it back out. It is a solid now. I attached the file.

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Thank you Val, but that really doesn't tell me what was wrong with my model, so I dont run into the same headache again.

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A more informed individual may have some insight into why for your particular problem. If I can't see an obvious reason when joining parts fail or I import files that fail to join properly I try importing them into other software packages to see if they process the file differently. I use open cascade and 123D design. Many times it just self corrects in at least one of them. It's fast to check.

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That's good to know. Thank you Val.
Upon inspecting the model further. I noticed that this edge doesnt connect to the point below it where it should. I tried deleting the face and adding a line from the end of the one to join them all and network a new face, but it never works.

Image Attachments:
5.JPG 

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Hi Billabong,

re:
> I have been racking my brain for 3 days trying to get this be a solid body. No matter what
> I do. I just cant get it and would really like some help on this please.

So the first step is to look at "naked" edges, which are edges that only belong to one face instead of being joined between 2 faces.

You can select naked edges by either setting up a shortcut key as described here: http://moi3d.com/forum/index.php?webtag=MOI&msg=6051.2
or in v5 you can do it in the UI in the scene browser under Types > Edges > Naked.

If you do that on your model these edges will highlight:



So those are the areas to investigate for potential problems.

The easiest thing to try at first is to separate out the surfaces in those areas and use Edit > Join to glue the pieces together again.

You can do that by selecting these 4 faces:



Then use Edit > Separate once to break that section out, then Edit > Separate again to break it down into 4 individual totally separate surfaces, then Edit > Join to glue the 4 surfaces together, then select the main piece as well, then one more Edit > Join and that is enough in this case to get a solid.

Sometimes the object may need some repairing or reworking in the places with naked edges but that doesn't seem to be needed in this case.

- Michael

Image Attachments:
naked_edges1.jpg  naked_edges2.jpg 

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Thank you Michael so much for helping me. So should i be worried about the edge that doesn't seem to go all the way down to the point in my previous post?

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Hi Billabong,

re:
> So should i be worried about the edge that doesn't seem to go all the way down to the point in my previous post?

Not really if it's a small enough distance away that it can get joined up ok.

It is generally good to try and have things meet up exactly when possible but things are set up to be able to tolerate gaps between edge ends or between surfaces as long as they are pretty small.

- Michael

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Good to know! Thanks again for helping me. I have thrown a few middle fingers at my computer over the past few days, lol.

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Michael, I have another area I cant seem to get to close. I tried your suggestion on this. I also tried creating a network, a loft and a sweep. None of them will form to the shape. Any suggestions?

Attachments:
Drone_v12.3dm

Image Attachments:
1.JPG  2.JPG 

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Hi Billabong, there are a few bits kind of sticking out along that boundary and there are a couple of tiny edges and one squished surface (looks like a line but is actually a surface with no surface area) that are making things complicated.

So to clean all that up I drew in a side profile and trimmed a thin strip away so everything would be cut to a common boundary, like this:



This way the area is filled by one trimmed surface like this:



- Michael

Attachments:
Drone_v12_2.3dm

Image Attachments:
drone_trim.jpg  drone_trim2.jpg 

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Thank you so much Michael. I'm still early in the learning phase, so I really do apologize if these are issues I should have realized.

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Im a little confused. You said you trimmed it and got that nice flat surface, whenever I trim using a path. it just cuts a line . Am I missing an important feature?

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Hi Billabong, sorry I kind of glossed over some of the details.

What I actually did in some detail is like this:

Deleted the current fill in pieces:


Take the profile curve that I had drawn in the Right side view and extrude it out into a surface:


Select both the extruded surface and the main piece:


Run Edit > Trim and at the prompt where it asks you to select cutting objects, just push "Done" without doing any other selection. This does a "mutual trim" where each object is being cut and working as a cutting object as well:
Push Done to finish the Trim command and leave the pieces, delete this piece:


And delete this little strip piece:




Then the 2 remaining pieces can be selected and run Edit > Join to glue them together into a solid.

If you're able to work on pieces as solids instead then several of these steps are handled automatically when you do a boolean. Booleans will automatically extrude out curves and leave the "side walls" that are generated from them and automatically determine pieces to discard and automatically join the pieces together. But booleans decide which pieces to keep based on what volume they are contained inside of so you need to be working on a solid to use them.

Hope that makes more sense.

So the other thing that is good to get used to is to try and plan in advance that you are going to be cutting pieces to a common boundary like this and so you want to let pieces extend a ways past where the cut will be. For both Trim and Booleans. Don't try to constrain surfaces too much to try and force them to directly follow the boundary in their initial construction that can make stressed surfaces that are kinda trying to do too much all in one go.

- Michael

Image Attachments:
drone_trim3.jpg  drone_trim4.jpg  drone_trim5.jpg  drone_trim6.jpg  drone_trim7.jpg  drone_trim8.jpg 

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Makes perfect sense! Thank you so much.

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