Hi guys,

I am in need of some assistance if you have the time. I'm currently working on a basic spray cap and for the life of me, cannot "union" or join the top grip with the rest of the body. I have gone over the model with a fine tooth comb and can't find the reason why it isn't working. If someone's willing to take a look for me, you'd me my hero :) I'm no stranger to modeling (see example image) but this one has me stumped lol.









Click bait :)

Hi Beanz, the booleans will have difficulty with it because the objects aren't closed solids.

It would probably be good to close off the orange piece to make it a solid, then you can use boolean difference to cut a solid by an open surface as long as the surface goes completely across the object and fully divides it into separate pieces.

So you've got 2 problem things, one is the orange object has a "naked edge" preventing it from being a solid. To see the naked edge, set up this script on a shortcut key as described here:
https://moi3d.com/forum/index.php?webtag=MOI&msg=6051.2

The naked edge is here:


It can be good to work on solids because when you cut a solid with a 2D profile curve you will get solid pieces with the "side walls" in place.

See these posts for some examples and explanations:

http://moi3d.com/forum/index.php?webtag=MOI&msg=5075.3
http://moi3d.com/forum/index.php?webtag=MOI&msg=3883.3

http://moi3d.com/forum/index.php?webtag=MOI&msg=1359.2
http://moi3d.com/forum/index.php?webtag=MOI&msg=1359.6

http://moi3d.com/forum/index.php?webtag=MOI&msg=4344.2

For your case here you can re-create the 2D profile curve by duplicating that naked edge, drawing a cutting line in the Top view and then using Edit > Trim to cut the edge in half:


Then you can use "Flat" snap on the edit frame in the Top view to squish it flat:


Then extrude it:


Then use Edit > Trim to cut the extrusion with the naked edge, discard these outer pieces and then the remaining piece can be joined to make the orange object a closed solid:


Then the other problem area is it looks like the ridges piece isn't quite fully crossing the other object.

If you have a cutting surface that goes all the way across a solid you can use boolean difference to cut it:




But if it doesn't quite go all the way across like this then it won't be able to cut it:


You've got that same kind of thing basically.

So I'll look at tuning up that piece next.

- Michael

All your pinky objects are just surfaces !
Make it volumes with real thinickness will give you some chance to make some boolean union with another "solid" volumes! ;)5 secons difference! :)


PS Crossing posts with 5 seconds difference ! :)

Then for integrating the ribbed area, it can be good to make an extended sheet, and cut away the excess rather than trying to make surfaces that try to hug the final boundary directly.

So like here using sweep:





Then to cut that you can use Trim, or for booleans there is a trick where you can select faces on an object and the boolean will only try to cut with those.

So if you select these 2 interior faces:



and also the ribbed sweep you can then do boolean union and it will only cut with those interior faces.

it will leave behind the ribbed piece and an interior piece, delete the interior piece:


And join the ribbed piece with the orange to make a closed solid:


- Michael

Guys, thanks so much for taking a look. I have done as you asked Michael and it has worked perfectly! I owe you a beer or two! :)