IGES large file(s) that are being used for space reservation only

I frequently receive mechanical equipment models in .iges format from manufacturers that I insert on my layout arrangement in Rhino.
Very often these models are very accurately modeled and therefore the size of my model is increasing dramatically especially when i have a big engine room arrangement.
Therefore i wanted to ask if there is a quick way to reduce the size of the models that i receive.
I m not interested to preserve the same amount of details but just putting a square bounding box is not an option either.
For example i have the pump which is shown below and is approx 100Mb while my layout arrangement is approx 50Mb in total without the pump)

Any ideas on how to make a lighter version of this would be really helpful.

The work around that i follow so far is that i convert it as mesh. Then i do mesh reduction approx.90-95% and then i do MeshToNURB to bring it back to Nurbs as the file exchange is always in iges or stp files and mesh objects are not exported.

Thank you in advance

Maybe a good option is select everything and use command _Rebuild and give U = 1 , U = 1.

Thank you but unfortunately that didn’t work very well for my case

Hello - it might be OK to Join then Mesh the objects to a very coarse meshes… then delete the surfaces - not sure here, since it looks like there are many skinny surfaces along the ducts that might or might not mesh very efficiently. Maybe a dose of ReduceMesh afterwards.


Sometimes the cleanest way to get a lighter model is to do a quick and simple remodel. Just looking at the screen shot it’s easy to see where the file size increase is coming from: all of that iso curve density in the fillets, the curved intake or exhaust ducting, the machined brackets holding the outer duct tube.

You could extract a few faces and extrude these shapes to exact outer boundaries fairly quickly. Extrude the bracket shapes without fillets and either polar array or Orient 2pt with copy. Take a few sections of the big curvy manifold tube and loft, Or just keep that shape as is.

What about just extracting and deleting the complex fillet surfaces alone? I’ll bet those shave off more than a few MB right there. Do you need the exported FPO model to be closed and watertight?

This method will let you retain more useful NURBs info for dimensioning in your other pipeline apps, rather than a chunky NURBs from triangles model.

You could savery those parts as separate rhino files and load them into the arrangement master file as worksessions or linked blocks. Last semester I loaded over 200mb of 2d and 3d city data into a master file that way and everything is still super smooth and quick

Do you mean that you just download stock models posted on a supplier’s catalog or marketing website, or are they supplied specifically for you by the manufacturer’s engineering or drafting department?

If the latter, perhaps they, at your request, could (more easily than you) trim them down to a more schematic but still usable version before they send it.

And maybe even if the former you could make it known that a lighter version would be a valuable addition to their website. This probably wouldn’t solve your immediate need but perhaps could start a desirable industry trend for everyone’s benefit.