# How to center sphere on top of chess pawn body?

I’m probably going about it all wrong. Thinking I should have made the pawn all one face and then used the follow me tool instead of the way I’m trying to go about it now.

At this point I’m trying to figure out how to sit the ball down and on center of the body.

Thanks,

pawn2.skp (1.4 MB)

Yep a uniform chess piece would be easiest made by drawing a half profile, and then “FollowMe” it around a circle.

As Dan indicates, it would be easier to draw the entire profile including the profile of the ball as one and run Follow Me in a single operation.

Also consider that you don’t need or actually want the horizontal edges on the profile. They’ll make the Follow Me operation more involved.

Yeah, your right, but I got it.

I had everything lined up already, but I was moving copies away and then trying to line them back up again.

All I had to do was the “followme” on the blue axes and then create the spear on the same blue axes. Then put it together before copy & move.

That’s like parking your car in the garage by building the garage around the car.

You really need to master moving things (of any shape) to a precise position, which is eminently possible using inferencing. You do yourself no favor by coming up with ways to avoid the use of inferencing. Whichever way you turn, the need to align objects using inferencing stands before you.

-Gully

Yeah, figures I’m still all wrong. Could you give me a example of how the two pieces in my model should be lined up?

Thanks,

As I presume you know, with inferencing you can lock movement along a single axis at a time. Now, if you turn on hidden geometry, you can see that your sphere is divided up into a grid of horizontal circles of latitude and vertical circles of longitude like a globe of the Earth. Assuming you have constructed your sphere on axis (as you should), there will always be a meridian (a great circle of longitude) parallel to the x axis and another parallel to the y axis. Grab any point on the x meridian and move the sphere along the y axis until it snaps to alignment with the vertical axis of your assembly, thus aligning it in y. Then grab any point on the y meridian and move the sphere straight along x, once again until you can snap to the vertical axis, aligning in x. The sphere is now centered on the x and y axes. Now just move the sphere along the Blue (vertical) axis until it’s at the correct elevation, or snap the equator to some point to align in z.

In other words, you can almost always align objects along one axis at a time, and frequently this is the fastest, easiest way to go. Although it’s a bit different from your present arrangement, the following picture shows a similar three-step alignment process:

-Gully

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I think not knowing about the meridian and to grab it at that point was part of my problem. I will practice, practice, practice moving spears today.

Thanks,

You don’t mean “spears”, do you?

You mean spheres, right?

It is important to get used to the idea of grabbing an entity by a point that can be snapped to a destination point. This will make it much easier to move the entity precisely.

Will the sphere be a separate part from the body of the pawn?

[quote=“DaveR, post:9, topic:21453”]
Will the sphere be a separate part from the body of the pawn?
[/quote] I guess so.

So in the image posted by Gully it shows a ring around the spheres Blue Axes.
I’m I to some how click and highlight the sphere to make that ring around it?

Seems all I can do is highlight the complete sphere before moving it.

Are you 3D printing these?

If you want to keep the sphere separate from the body of the pawn, an alternative method would involve drawing the sphere in its final resting place while leveraging the power of components along with Copy and Paste in Place. Then you don’t need to move the sphere into place at all because it’ll already be where you need it. Most of my modeling is done that way because I can use parts I’ve already drawn to get the shapes of mating parts.Much less work that way.

My goal is to learn SketchUp for 3D printing.

I like that idea, thanks!

As gully said, turn on hidden geometry to see the rings that make up the actual geometry.
Go to the View menu and tick Hidden Geometry.

I added a depiction of the relevant great circle for each move for illustrative purposes. All you really see is the hidden geometry in dashed lines. It’s up to you to discern the right one to grab.

It’s like when Batman hits someone, it doesn’t really write “Pow!” in mid-air even though the comic book shows it that way.

(By the way, “meridian” isn’t a SU term. All the language about meridians and equators and latitude and longitude is borrowed from geography, because it describes the geometric elements of a modeled sphere so well.)

-Gully

As far as I remember, the TV series did the same.

Anssi

You’re sort of an old dude, aren’t you? Of course, as I think we have previously established, I am older yet. Oy, my back.

-Gully

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