Mechanical design
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sometimes... for like inventions and such... you?
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Yes I'm a inventor and autocad user but I downloaded and now trying to use SU
I work for local goverment so a lot of my work is urban design, I like the photo match and sketch over, its great for concept design and approvals. SU is lightweight and quick to design with...just some more assembly tools would be good (like inventor)..but hey its free! Andrew -
I use it to work things out, mostly things that I build in wood. Level of detail is from extreme to rough.
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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
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Bob
How do you assemble the conponents in SU ?
Just simple move and copy commands and do you have some ruby's to help
Andrew -
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
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I only do mechanical stuff ......
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Bob
So if you have a bolt and a nut with a centerline on each, how do you then constrain them together ? Andrew -
Bob see the attached
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Dear Andrew,
I assume that you would like to move the one component so that it is co-linear and in contact with the other. For this example I would use a Ruby called Align-tool.rb (see http://www.crai.archi.fr/RubyLibraryDepot/Ruby/em_edi_page.htm). Open each component and construct x- and y-axes (the z-axis being the centreline of the component). Then select the one you want to move, right click and select 'align' (after installing the Ruby in your Plugin folder). The Ruby asks you for a start orgin, x-axis and y-axis and then a target orgin, x-axis and y-axis. Use the short lines you edited into your components to achieve the alignment and the correct orientation. Delete the short lines.
It would be very useful if Sketchup had alignment elements which could be deleted globally.
Hope this helps.
Kind regards,
BobPS. I will be away until Thursday, so if you have any more questions..
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Watkins,
Great little tutorial about the align tool. I've needed to use this tool and was a little baffled on how to use it. Thanks.
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Another trick which would help a lot is the option of making it impossible to put two things in the same space at the same time. I don't know if that is possible in SU, but I note that in the "walk around" mode, you have the option of not being able to walk through objects.
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