Making axial assemblies?


I am brand new to SketchUp but have previous experience with solid modeling. I am trying to make a transmission assembly of multiple components for the first time. I am finding it difficult to manipulate and move parts into the correct position. First I assume that the Import option is correct for adding parts to an assembly? 2nd the orbit function doesn’t seem to work well is it possible to reposition the orbit rotation point or origin? 3rd I can’t seem to align parts axially very well is there a good tutorial for assemblies and aligning parts?


What does this mean? You can certainly add components to an assembly.

The orbit tool orbits the camera about the model. The center of the orbit is located on the part of the model where the cursor is located when you click to start orbiting.

If you set up your components so their insertion points are on the axial centerline, you will find it easier to position them. The component’s origin is its insertion point. It is also possible to position components with just the Move tool.

Since you are new to SketchUp, you should take some time to learn how to use the Move tool and navigation tools.

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Thanks for responding to my post. I went through the 4 tutorials on the website. For some reason the mouse does not control the viewing controls like it should. The only thing it can do is zoom with the scroll wheel, the other functions don’t work (pan, orbit) do you know how I can fix this ? Its a std. Logitech design that normally works with everything fine.

Is there a way to limit selection of points to certain categories? When many parts and features are close together and also aligned similarly it has been difficult to get it to select the desired point for alignment?


Look at the setting for the center mouse button in the Logitech settings panel… Set it to middle button.

I don’t understand what you’re asking for.

Ok I got the mouse working thank you. When you have a lot of parts with a lot of features I find it difficult to select points from one particular part or feature. Other modeling programs have more defined point selection procedures where you can go through menus to find the point you are looking for. Just wondering if there is something like this in SU because hovering the mouse around to find a point can be difficult in large assemblies with lots of parts and points.

Although I got the middle mouse button to orbit, I’ve found that the orbit point seems to be at infinity or something, such that it’s impossible to rotate it laterally (azimuth direction rotation) - I can’t get a ‘side view’ its making work impossible. Seems to be this way for all parts I import.

You can add temporary geometry to components if you need to do it. It’s
also useful to be active with zooming and orbiting. You can zoom in to pick
a point on a small detail with the Move tool and zoom back to see a larger
area. With practice that’ll get to be second nature.

The Orbit tool orbits about the point on the model where you click. If you click on a point in the distance, it’ll orbit about that.

Also, make sure you are working with the camera set to Perspective. Working in 3D space is much easier that way.

Thanks again, I have it set to perspective. I want to be able to flip the part around in any direction I choose but it doesn’t do that apparently. I can’t even rotate the part to a new orientation because selecting points for the rotation tool is so frustrating and time consuming, This is extremely annoying and frustrating. I want to manipulate the part/assembly orientation not my ‘perspective’. Think I’m going to move on to a better platform. I’m not building a house I’m making mechanical assemblies.

The most basic method of modeling an assembly, I think, is to model the piece parts in place, or at least within the confines of the using assembly model, so the question of “bringing in” parts need not even arise. That leaves three other methods, which you would presumably choose from depending on the exact circumstances. Parts saved in Component libraries, which can be brought in through the Component browser, are generally reusable or multi-use parts. Parts that are modeled in a separate file but are not intended for multiple usage may, as you observed, be brought in through Import > .skp. You may also cut/copy and paste objects between two open sessions of SU.

Inferencing is SU’s system of object snaps and dynamic guidelines. All questions of positioning and alignment come down to inferencing. Once you have gotten a feel for inferencing and how to interpret the on-screen feedback it provides, alignment tasks become too easy to talk about. Until; you have, it’s almost pointless to try explaining how to align things. So I would say that you should take a temporary detour from your planned project and learn everything you can about inferencing from videos and the written word, and practice applying these techniques until they become comfortable. Doing that will make everything you do in SU easier, or, say, possible.


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SketchUp is a surface modeler, that can treat watertight volumes as “manifold solids,” for the purpose of export (or in the Pro edition, for boolean operations.)

Selection of objects is actually a different thing, so I’ll rephrase this as:

"Is there a way to limit inferences to certain categories ?"

There are some ways to modify inferencing. Clicking the SHIFT key can lock the current inference, for most native tools. (Ruby plugin tools should follow this, but some do not.)

For v2016+, the arrow keys lock the X-axis (:arrow_right:), Y-axis (:arrow_left:), Z-axis (:arrow_up:) or the plane (:arrow_down:).

This is usually called something like “Osnap” or Object Snapping. (I believe SketchUp’s sister application LayOut has this.)

This (finer control) is an often requested feature. I would welcome such a feature, like a mouse-context menu where all inference snaps are checked by default, and you can uncheck those that are getting in the way of the current operation.

I might also welcome control that allows limiting inferences to only the current editing context, … such as only within the group being edited. (Again, a temporary right-click context menu item.)

I am always in favor of letting the customer use the product their way.

The following is pasted from another recent reply of mine, to another SketchUp beginner, (who seemed to not know basic geometric terms and operations. I paste it here mostly for the links.)

You usually place components, at a point (which is the origin of the component’s local axes,) with respect to some other inference point (or face) in the model. (This is called a translational transform.)

:mortar_board: SketchUp User Guide: Finding and locking an inference
:mortar_board: SketchUp User Guide: Knowing your inference types
:mortar_board: SketchUp User Guide: Locking inferences with a keyboard

Then you orient the object with respect to the model’s axes, or one of the axis. (This is called a rotational transform.) In other words, you rotate objects about an axis. This is the first thing that the RotateTool wants you to indicate,… the point of this rotational axis. The second point will be the starting point for the rotational angle. The last point will be the end of the angle.

:mortar_board: SketchUp User Guide: Flipping and Rotating

So, if you placed a fence component on the ground plane. To rotate it so that it’s longest run is lying along the green axis, you will need to rotate it about the blue (Z) axis.

You can always move it again after rotation, to snug it up against the corner of the house, etc.

:mortar_board: SketchUp User Guide: Moving Entities Around

(FYI: The place component feature is a form of the MoveTool.) After placing a component (from the 3DW or your local components library,) just hover over this instance and you’ll see little red rotate crosses appear. If you stop over any of them, the tool switches (automagically) to the RotateTool. These rotate crosses can appear on any of the bounding box sides of the component instance. This makes it easy to immediately rotate components just after inserting them. (But you can do this at any time to component instances, using the MoveTool.)

:mortar_board: SketchUp User Guide: Editing components

NOTE: The axes indicator lines you see displayed in the model, are initially positioned at the model origin. But they can be moved at any time, using the AxisTool. This can be handy because SketchUp’s inference engine will use them as snap lines (by the inference engine.)

:mortar_board: SketchUp User Guide: Adjusting the Drawing Axes

[quote=“sekramer10, post:9, topic:22640”] I want to manipulate the part/assembly orientation not my ‘perspective’.

SketchUp was designed to easily change camera perspective. It is very easy to change the camera angle between standard views, if you open and dock the “Views” toolbar.

You can also create scene pages for any particular camera view you need, give them labels that have meaning for you, and quickly switch to them by clicking their scene tabs. (Turn on Scene Tabs via the View menu.) Each scene page can save what layers visible/hidden and what geometry is hidden.)

Also scenes can have their own display style. My standard template has a “Thumbnail” scene, a “Print” scene and a “Work” scene,… each with their own style for their particular purpose.

There is some built-in Flip Along functions on the right-click mouse context menu. If you select a component, they will be on the menu.

There are also Mirror plugins.

Thanks you have been helpful. I think I’ve found the problem with orbiting is that the orbit only rotates around 2 axes at a time. And I see this can be changed by changing the camera view. This is really counter-intuitive for me, I am used to ProE and Catia where you grab somewhere near the part and then when you move the mouse the part rotates with it generally in the direction you want to rotate the part. For instance in the right side view I can’t seem to just tilt the part around the green axis. Very easy for the red and blue, but almost impossible to rotate about the green axis just to tilt it to get a better view. I don’t quite understand that yet. I wish there was different object manipulation options, do you know of any plugin like this? BTW I need to build an assembly of many pre-made parts.

True. If you rotate the view horizontally around the blue axis, 90 degrees (either way.) Then let up on LMB, and reposition above or below the part, then hold abd drag up or down, you should be able to get any viewpoint you need.

Sorry. SketchUp was designed purposefully to not be CAD-like, especially in the GUI and interface. No command window, no multi-key commands. Automatic inferencing. etc. It’s motto is “3D for Everyone.” That means also for schoolchildren.

There are some camera manipulation scripts. I’ve written some myself. There is a spin about animation example by the SkecthUp Team. Have you searched the Extension Warehouse or SketchUcation PluginStore ?

You do understand that SketchUp does not have true circles or arcs ? They are a series of line segments in SketchUp. But they can export to DWG as true circles. Have you tried FreeCAD ? It’s GitHub Code repository says:

FreeCAD is a general purpose feature-based, parametric 3D modeler for CAD, MCAD, CAx, CAE and PLM, aimed directly at mechanical engineering and product design but also fits a wider range of uses in engineering, …

So, hey, let’s admit it. There are some people who do not care for the simplicity (or the “hand holding” inferencing) of SketchUp. Some people with years of experience with more complex CAD, feel right at home in those kind of applications. (And feel lost inside SketchUp.)

Yeah, I actually hate SketchUp very much right now. Spent 4 hours doing something that should have been done in about 2 minutes. Waste Of Time - Bye Bye! Good Luck!

What exactly was that? Allow some experienced users to show you how it’s done and how long it takes, to give you some basis for comparison.


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