Having problems stacking things

[jtpryan]

I have created a 3.5" x 3.5" x .75" block, a 2.5" x 2.5" x .75" block, and a sphere. Now I want to stack them all so that they sit centered one upon another. I can't seem to get this to happen, I keep getting all messed up in the different planes. I can draw construction lines and place the smaller block upon the larger one, but this seems like a work around and there must be a simpler way. The sphere is particularly difficult.

I have looked at a bunch of inference tutorials, but they all speak about aligning corners and sides, not the center of a surface.

Thanks,
Jim

[sorgesu]

without using ruby scripts to place construction points at center points, which is one way to do it, you can use the following inferencing techniques:

assuming you wish to place the cylinder on the block.

1.Pre-Select all of the cylinder
2. Activate the Move tool.
3. to find the centre point of the botttom surface of the cylinder you can touch your cursor to one of the end pointis of one of the segments of the circumference of the circular surface. This will "remind" SketchUp of the inference points that make up the geometry of the circle. Then, as you move your cursor toward the centre of the surface it will want to snap to the "center" point which will show as a green dot and label. Click on it with the Move tool to grab the cylinder by the bottom center point.
4.Turn on X-ray mode.
5. Hover over the top surface of the cube and touch your cursor, still hanging on to the cylnder, touch it to the mid point of one edge of the top surface of the box. As you pull toward the center there should be a dotted green or red line depending on which axis you are parallel too, showing you the inference that you found. Next touch your cursor to the mid point of one of the edges perpendicular to the first. Having found the 2 perpendicular mid point inferences you should be able to move your cursor so that both coloured dotted lines from both midpoints show and there is a snap to centre and a label that I believe says "from point". That is where you click to deposit your cylinder. All lined up mid point to mid point.
6. Turn off xray mode.

[remus]

I tohught he said spere...

[sorgesu]

not long time in country. Sorry.
With a sphere. Turn on hidden geometry. Select the whole spherE. center point is readily visible with hidden geomtery. Click with the move tool on said centre point and proceed as I explainde above.

If the center point of the sphere is on the wrong axis for your placement requirements, there are a number of ways to proceed but one way is to rotate the sphere from it's center point 90 degrees and then continue as above