make hollow cylinder polyline

[Lighthouse]

Hi, in X12, is there any way to make this shape a hollow cylinder.  Trying to get 1/8" wall thickness.  Normally I would create a solid hole but it doesn't work with the shape.  I have also tried to make two hollow straight cylinders and join them but they don't miter properly.  thanks

[Larry_Sweeney]

Make this shape with a molding profile. Then, if you need/want too, convert it to a symbol and put it in your user library. Seems simple enough if I'm following what you're asking for.

[Lighthouse]

I'm trying to make it hollow

[rlackore]

Maybe there is a more elegant method, but here's one way:

1. Draw two concentric circles, one for the outside diameter, one for the inside diameter.

 

2. Use the Convert Curve to Polyline tool to turn both of them into polylines with a high number of sides. They both should have the same number of sides.

 

3. Zoom in to one quadrant and break both polylines along opposite sides. Here I used two lines and the trim operation, but do it however you want.

 

4. Join the two polylines to create a single closed polyline.

 

5. Drag one edge down to butt against the other edge.

 

6. Save the polyline to your Library and use the Molding Polyline tool to draw a molding in the desired shape. You now have the shape you desired.

 

[Larry_Sweeney]

Sorry David .......my bad!   Played around a bit. This is kind of drawed out depending on what you are doing. 

1. make a solid cylinder the total diameter you want.

2. make another cylinder the diameter of the inside size you want and make it a little longer

3. set it centered inside the larger cylinder and then subtract it from the larger one.

4. you now have a tube.

5. copy it and turn the copy 90 degrees to the original

6. make a large square solid and turn it 45 degrees to the cylinders.

7. line it up so it will subtract a 45 degree piece all the way across each cylinder

8. add the two pieces together to form one 90 degree elbow.

 

OR just do it in SketchUp . I'm sure there are easier ways. I just haven't had enough coffee yet this morning.

[Lighthouse]

thanks, I ended up having someone make it in SU, I'm too rusty.  The problem with chief is that even with a high number of sides, it doesn't make it round enough to 3d print a smooth shape.

[Lighthouse]

that said, thanks for your method and I will try it for next time!

[rlackore]

35 minutes ago, Lighthouse said:

thanks, I ended up having someone make it in SU, I'm too rusty.  The problem with chief is that even with a high number of sides, it doesn't make it round enough to 3d print a smooth shape.

Interesting. SketchUp is strictly polygon based - circles (and extrusions thereof) are multi-sided polygons. In Chief I easily converted a 6" diameter circle into a 2000-sided polygon with each side measuring 0.014" - pretty high resolution. Perhaps there's an issue when converting to a 3D-printing compatible file format.