Trouble creating concentrical cylindrical voids

#1

As my first very simple thing to model in SketchUp, I am trying to make a square box with a ‘double’ cylinder void. I am going for this:

outline.png1522x1356 73.3 KB

I create it by

1: Make a rectangle
2: On the rectangle create a circle
3: Pull the rectangle up
4: Create new circle on the top level of the pulled rectangle
5. Pull rectangle with new circle up

My problem is with step 4 where I cannot work out how to select the second center to have the same x- and y-coordinates as the center for the first circle from step 2. When I select the same center in a higher z-xoordinate, it seems this is interpreted as wanting to create a sphere or ar least something in a plane perpendicular to the first circle’s plane:

second_cylinder.png972x684 27 KB

I made the first sketch above by choosing the second center to be a bit off compared to what I need for the printed model.

How can I obtain step 4 with the same xy-location ?

#2

Try 4: select circle on pulled rectangle, then offset circle. You get the same center.

#3

It would probably be easier all around if you were to simply describe what you want to model and ask for a workable method, rather than take us through an involved method that doesn’t work and ask for help with “step 4.”

Generally, the easiest, most accurate way to make a counterbored hole in something is to make the thing and the hole separately and then just put them together. This method also allows you to intersect a curved or angled surface with a hole or stepped hole, although in this case I’ll make the hole just the right length to start with. Thus:

holeinbox.jpg738x671 71.1 KB

-Gully

#4

Also, see the following: How do I draw a rectangle or circle (or polygon) oriented vertically?

#5

A simple version, drawing your circles before pulling.
The circle tool will find the centre of the circle.

#6

Thanks to all for the replies. A wonderful program with a lot to learn!

Box’s solution is very nice and simple for my purpose.

#7

If you’ve already got one circle, I would just use the “offset” rather than draw another
(But you will probably encounter problems with this method if it’s for 3D printing)

#8

Offsetting works with circles (the result is a “circle”) but not with Arcs. This might be irrelevant to 3D printing, as the printer usually reads the 3D polyface surfaces and not the underlaying geometry. On the other hand, if you do simple paths for cutting with a CNC machine, the result might be smoother with “real” arches and circles instead of segmented ones.

Anssi

#9

What I should have said was, “What’s the matter,@RookA1, at a loss for voids?”