Dear Andrew,

That is a tricky one to answer. I use different alignment techniques for different components, but generally, alignment requires a lot of forward planning when drawing. When drawing inside Inventor I use a tool called 'Constraint' which provides many options for aligning components. It can be tricky tool to use, particularly when used with big assemblies.

The rotor assembly described in my previous post uses a lot of axially symmetric components, and so the alignment was fairly straight forward. I drew a 1/2 section of the assembly in AutoCAD, imported the file into Sketchup (with the centreline), aligned the centreline of the 1/2 section with the blue axis, drew a circle on the red-green plane and centred on the origin and then used the 'follow me' tool to create the 3D shapes. Adopting this approach ensures that all components are correctly aligned.

The frame was drawn drawn inside Sketchup using different techniques. I used construction lines to mark out the positions of the support feet and then built the frame from the ground up, so to speak. I used construction lines to create alignment features on the support feet so that I could position the box sections etc.

When drawing 'inside' Sketchup I first create the component and open it to edit it. I then add alignment features which 'travel' with the component when it is closed (end edit) and moved. For example, suppose I want to align a bolt with a hole. When drawing the components I add centrelines to both the bolt and the hole so that I can use the ends of the centrelines for alignment. In the case of the bolt one would draw the centreline as long as the bolt's shank + threaded section so that the bolt snaps to the hole with the bolt's face against the mating part.

I also use TIG's AddVertex+.rb to add alignment points within the component (inside edit). The construction points then travel with the component when it is moved. What you have to avoid doing is using Delete Guides as this will delete the alignment points created by AddVertex+.rb.

Hope this helps,

Bob

I use Sketchup to mass model assemblies. I also use AutoCAD 2007 and Inventor 11. The attached shows a rotar assembly for a high speed rotating table. The table, which is driven by a hollow shaft torque motor, is required for Geophysical Fluid Dynamics research. Sketchup is just perfect for sorting out the good and the bad designs before implementing in Inventor. This approach saves a lot of time. If any Ruby script writers are reading this then please think about writing an exporter for exporting surfaces as either a .step or a .iges file. I could then import these files into Inventor and complete the design process.

I have also attached a .jpg showing a support frame mass modelled in Sketchup. I did this as an exercise long after the frame had been built and used. The frame was used to support a 169M USD space instrument in our vacuum chamber (see http://www.atm.ox.ac.uk/main/facilities ... index.html)

Kind regards,
Bob

Dear Gaieus,

Not to worry, I did not take your comments as a criticism, but merely a request for clarification.

I think this site is a wonderful resource for the Sketchup user, and I would like to thank you and all the other contributors for all your hard work.

Kind regards,
Bob

Dear Gaieus,

After having created the outline of the rectangle/square using guide lines (construction lines?), I use the rectangle tool to make the plane by snapping to the intersection points along a diagonal. The method using guide lines allows one to create construction planes at any point and in any orientation in 3D space. This is useful if one needs to create a 'sketch plane' for an extrusion (such as a hole cutter) to intersect with existing geometry. If you use the VCB box as you go then the last step (using the rectangle tool) defines the plane nicely.

I am using Sketchup and AutoCAD to mass model a new high speed rotating table for a geophysical fluid dynamics experiment. Once I am happy with the configuration I will switch to Inventor which is a parametric 3D modelling program with all the bells and whistles. Inventor uses sketch planes to create geometry and so my approach might be coloured by my familiarity with this software. Why am I using Sketchup when I have Inventor? Because it it is so quick and easy to develop ideas using sketchup, and at the configuration stage I do not need the detail available with Inventor. I am also using sketchup to design a new extension (kitchen and bathroom), which is the reason I started using sketchup in the first place

Thank you for your welcoming remarks. I decided to contribute because I should not like to be considered a 'lurker'.

Kind regards,
Bob

Good morning Gentlemen (08:00 GMT),

This is my first posting, and so if I get the protocol wrong then my apologies.

I use the measure tool to draw planes in any orientation and at any height. Using the measure tool, 'draw off' construction lines off the appropriate axes. For example, if a rectangle/square is required on the blue/green plane, then select the green axis and pull up a construction line from the axis. Then select the blue axis and draw across a construction line from the axis. You can trace along the green axis when pulling off the blue axis to ensure that you are pulling the construction line in the right direction. Better defined inference points can be created at the points where the construction lines cross the axes by creating construction lines along the axes (use the measure tool, and click at two points on an axis).

Variations on a theme:

Use the protractor tool to set the orientation of the bottom edge of the rectangle/square before drawing up and across.

Use more than one construction line to set the upper and lower edges of a rectangle/square on a plane.

Use absolute [x,y,z] and relative <x,y,z> co-ordinates to create guide points at any point in 3D space. Draw off guide lines and use the protractor tool and snap to the guide points to create planes at any point and in any orientation in 3D space.

You can enter values into the VCB to size the rectangle/square as you go.

Kind regards,
Bob

Dear Susan,

You mention that your hard-drive is pretty full. When running 'Disk Cleanup' did you select 'compress old files'? If you go to 'Windows Explorer' and select 'My Computer' in the address box, then 'Local Disk(C:)' should be in black. If it is in blue then your C drive has been compressed. Windows decompresses compressed files on the fly, which can take time.

I think the solution is to mirror copy of everything onto a hard-drive with more capacity and then decompress the C drive. It sounds like you could do with more capacity anyway.

Kind regards,
Bob

Dear All,

As a stop-gap, you might try using calc.rb which you will find at:

http://www.crai.archi.fr/RubyLibraryDepot/Ruby/em_sections.html

and filed under File-Converters-Misc. When you select it from the Plugins drop down menu it brings up a simple but perfectly adequate calculator, allowing you to work within Sketchup.

Kind regards,
Bob

Dear Didier,

I should like to thank you for all your hard work. The revised scripts and tool-bar are excellent, and a real help to those who want to project geometry onto a sketch plane. I need to do this frequently when designing mechanical components.

Thank you once again.

Kind regards,
Bob

Dear Gidon,

If you select the Edit drop-down menu at the top then you should see 'paste in place' as one of the options. It is certainly there in my free copy of version 6.

Kind regards,
Bob

Dear Gidon,

I would like to claim brilliance, but the reality is that I came across the technique by accident.

The copy and 'paste in place' are powerful features of SU, and I suspect, very under used.

Kind regards,
Bob

Dear Gidon,

You might try the following.

Draw your leader line. Delete the default text, press the space bar while in the text box and then click outside. This will leave you with a leader line without text. Select the leader line and then execute the copy command. Then select 'paste in place' from the drop down menu. Then select the text tool and hover the arrow of the text tool over the arrow of the leader. Click and drag, and if all goes well the two leader lines should separate while remaining fixed at the end connected to the short text line. Repeat the above procedure for an infinite number of leader lines linked to the same text line. Rotate the model to confirm that the multiple leaders are indeed connected to the same text line. To add text, double click on any of the leader lines and hold down the mouse key on the second click. The text box should appear. With the key held down move the pointer onto the text box and type in your text. This ensures (I think) that only one text box contains the required text. I imagine that the other text boxes are there but empty. Experiment!

Seems to work for me (free version of V6).

Kind regards,
Bob