Can't draw half cylinder with rounded ends

I designed an entertainment console with 2"x2"x31" legs. In the center of each leg, I will add an accent by plunging a 1/4" round router bit in for 27.5". I would like to draw it in Sketchup first to figure out the right balance of height compared to the surrounding drawers and cabinet doors.

I drew the 2"x2"x31" legs. I would like to draw a half cylinder that is 1/4" x 27.5" with rounded ends then subtract them from the center of the legs. I first tried drawing 1/8" x 27.5", round the corners and rotate follow-me around a circle. It drew strange things. I spent a lot of time trying to draw the 1/4" sphere to put on a cylinder but I hit the limit on size and had to draw it large and scale it down. I was unable to lock the sphere on the cylinder.

After I realized that I had been hitting a size limit with the sphere, I dropped back to drawing the half cylinder at double size. That got closer but still doesn’t work. I have pasted a screen shot.

What is the trick to drawing this half cylinder so that I can subtract it from the leg?
Is there a better process than subtracting it from the leg?

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Easiest way would be to draw a whole cylinder with rounded ends and then split it in half. You will likely need to work at a larger scale than you currently are to avoid the holes.

If you really want to draw only half of it, you need to make the arc path so that it is perpendicular to the profile at both ends. You can easily do that by dividing a circle through the midpoints of opposite sides.


Thank you for the very quick reply! This looks exactly like what I was doing.
I tried it at 10x and it worked. Then I scaled it down.

The next problem is that I can’t subtract it from the column in the free version of SketchUp.
All that work for nothing.

Only the pro and shop versions offer the solid tools. In free and Make, you must right-click:Intersect Faces With… and then erase any extra geometry.

It’s OK. This is the same technique used before solid tools existed. (Intersect Faces as Steve says.)

Thanks for your help. I got it to work.

After hours of playing around with it, I was finally able to delete the face of the object to reveal the inside of the cylinder. It’s not as easy as a cylinder that stops on the surface or goes all the way through the object.

It should really be that difficult. If you place the flute such that it’s edges are on the surface of the column, you should only need to remove the skinning face.

I can’t erase the face because there is nothing to click on.

Can you share the SKP?

I attached the file.

entertainment-center.skp (192.4 KB)

After I got it to work once, when I undid the basic cylinder, I lost it and could not get it to work again.

Selecting the face skinning over the flute and hitting Delete works for me.

I’m not sure what you mean by: “After I got it to work once, when I undid the basic cylinder, I lost it and could not get it to work again.”

If you want to have a flute you can use repeatedly, make the flute as a component which, after it is placed, you explode before deleting the skin.

THANKS!!! That worked!
My problem is that I kept trying to use the Eraser tool which required an edge to grab.

Eraser only works on edges. To erase faces only, use Delete.

FWIW, you should avoid applying materials to your model until it is correct and the face orientation is right. In your model, the faces in the flute are reversed which can be problematic. You should reverse those faces.

Thanks for the tip. I would normally wait until the end to apply the texture but in this case I wanted a clear indicator that I was looking at the inside.

Now, I am trying to do a tapered chamfer to mimic the router chamfer bit starting and stopping down from each end.

Think about the volume of space the bit would pass through and model that. Then intersect that shape with the part getting the stopped chamfer.

Those chamfers are exactly what I am trying to do on the leg.

Did you create a triangle shaped component then subtract it from the edge?

If so, did you start with a square rod, round the ends then cut in half to create the triangle shaped component?

No. That’s too much work. I drew the path a router bit would have to follow and used Follow Me to extrude a triangle along it. Like this. Since I’m using SU Pro, I could use Subtract from the Solid Tools, or better, Trim from Eneorth Solid Tools but you could use Intersect Faces and erase the unneeded bits.

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Thanks for your suggestion to use the tool path process. I tried several times to attempt the tool path that you described on FineWoodworking. Maybe I am too new to SketchUp to know the subtleties but I can’t make it work.

I dropped back and made the material that is removed then Intersected Faces and deleted the extra. I found deleting all the segments to be tedious. I attached a screenshot.

Is there a faster way to delete these pieces without clicking on every single one?

When you learn the right technique that should happen less. But let’s say you do have to clean up something like this. Use the Soften Edges window to make the faces into continuous surfaces. Select all of your edges and faces involved. Then HOLD SHIFT and double click on the surface you want. Then that surface and its edges will be DE-selected. Hit Delete to get rid of the parts you want to clean up.

In this particular setup you DON’T want to “soften coplanar”. You can also be more selective in softening by using the eraser tool and the option key to soften individual edges.