Two internals arcs meet - how to deal with the join


Hi hope you can help with this simple one…
Bit of a newby having a play around with sketchup to hopefully utilise a 3D printer.

As below I have two internal arcs which i have used push and pull to create the internal arc.
Where my top arc and bottom arc meets, I want to invert the shape rather than be left as shown at the bottom, how is this done??! Does that get across what I’m trying to do!!? (imagine a test tube imprinted into the tall piece, this is the internal detail i’m after).

Thanks in advance.


Maybe this?

(edit) Revised simpler method using arc.



Try undoing the push pull, cut the arc in half, and using the follow me tool. This might leave some geometry down the middle that may need cleaned up. Another option would be (in pro version) draw the test tube shape with the lathe function of the follow me tool, group and subtract with solid tools from the prism group.


Or this?





Gully’s way wins the fewest steps award!


The OP appears to be after something less than semi circle. Does that matter to these processes? Perhaps a bit.



With the technique I showed, you could just move the tube part way into the rectangular solid.


Here’s a variation of Gully’s method. It should work also with an arc that is less than a half circle.



I dunno about when it’s a partial circle. I got this typical oops from follow-me, probably because the arc meets the face at a shallow angle instead of perpendicular to the follow-me profile.


my version…



how do you set gifs? as active on here???


I just uploaded it, nothing special…


If they are over a certain size they are thumbnailed. What that size is, I don’t know and so far haven’t gotten an answer.
Perhaps you’ll do better.

Dec 14 Meta category



If you mouse over your gif, a bar appears with a double arrow at the right. Click that and it enlarges and then animates.

So now we have variations that should cover just about every interpretation of what the OP may have been trying to do! :smile:


I reduced it from 500kb to 300 odd and it still doesn’t auto run…
so this is 270
and didn;t run…
they all run in the preview window…


By trial and error, I’ve guessed it’s about 480 pixels in either direction. Only a guess.


Thanks for all the responses gents.
Shep, you’ve got it spot on for what I am trying to achieve…

I have a gremlin however.
When i use this method on the scale I am using I get the below.
When i use this method on a larger scale seems to work fine?

My column dims are 6mm width, 17mm depth, 55mm height.
The arc is 11mm across, set in 3mm each sides and from base with a depth of 3mm, any ideas why it is doing this based on these dims…?
The item is going to be a bespoke phone holder for a car so it is not a large item, I’m drawing to scale for 3D printing.


Much has been written about the “tiny face” limitation in SU. It’s best to scale the whole thing up by a factor of 100x or more. Or, make the object a component, copy it and scale that one up. Do your editing on this “remote component” then just delete when finished and your small one should be just right.

But in this case, you need only draw two lines. Better to turn on hidden geometry (shortcut key H) first.



Cheers Shep.
I have just scaled everything up by 100 for now, don’t know enough about components etc…
This works fine. When i’m done with the design I just scale back down, or is that the point i have to learn about components!!!