I am helping with a B-17 restoration project and we recently had a major component scanned. It is a big part and the STL file is large at 440MB. The scan has some holes in it. We can see the STL using the slicer software for a 3D printer, but this file just bogs down SWX. I am using SWX Pro 2020 and also have 2021.
Does anyone know if SWX 2022 has more capabilities to deal with STL files? I have not bothered to install 2022 yet, but will if it can give me something usable.
Is there a SWX add-in that can do the job? I have no experience doing surfacing so this seems intimidating.
Since we can open the file in Chitubox slicer software rather easily (it even slices it despite the holes in the scan) is there a slicer program that can convert (Save As or Export) to a usable file format?
I was able to open a smaller scan with similar holes in Onshape and saved it out as STEP, Parasolid, ACIS, Object, and IGES formats, but if they opened in SWX they were still the unusable mesh surfaces.
If we can get this STL converted to surfaces or something we can reference then we can repair the holes and make a complete solid.
Our objective is to eventually get a casting of this part. We do not have drawings for it, apparently they don’t exist (according to the professional historian leading this project - - and he’s found just about everything else!)
Thanks in advance.
If you can make the STL file available as a download somewhere, I can open it in DesignX and have a go at repairing the holes and turning it into SW geometry.
I don’t know Onshape tools, but sounds like you saved the Mesh Data inside a Step, you need to convert the mesh to NURBS so you can use it as surfaces.
For that you will need a Reverse Engineer software, like Geomatic DesignX, PolyWorks Modeler etc. Rhino7 has QuadRemesh as an affordable option.
You could also fix and decimate the mesh in a specialized STL mesh editor or a 3D computer graphics software (Blender, ZBrush, 3DS Max, Maya), lowering the amount of data makes it better to import in SolidWorks.
Those software can’t convert it to NURBS, the STL mesh will be more like a reference 3D image while creating sketches/features in SolidWorks.
Austin, I have SWX Professional, 2020 and 2021 installed on my computer, mostly using 2020 for this work. I have not yet seen a burning need for it, but I am current on my license so I can install 2022 if necessary.
I tried just doing the base-revolve that seems like the main feature, I think it came out pretty good for something really quick and dirty. I think this is the route you will want to take if you want to recreate the part with something other than a 3d printer.
I do not know all the specifics of the origins of the part and I have not seen it in person. The folks working on this aircraft rebuilding project are all over the country. If we had the drawings all would be made clear.
This part was made in the early 1940’s for a B-17. I suspect the only viable option for making it at the time was by sand casting. The part that was scanned is from a surviving aircraft so it had been finished. Probably not all the surfaces were machined or hand-worked, but certainly some were.
Our goal is to develop a solid file that represents the part we scanned and then to use it as a starting point to talk with sand cast vendors. With their feedback we will add material to the model to make a configuration for the cast version. Any shrink factors they need would be easy enough to apply as well. From there they can use the cast configuration to make the patterns for the sand casting.
I reduced the triangles in Magics so it is easier to import in SW and use it as a reference image to create the solid:
One has 16MB and other 3MB
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Btw, this scan should not be done in fine mesh quality. It will create huge files like the original one and will be super hard to work with it.
Also using a scan spray to increase the quality and reduce noises is a good idea. A few minutes improving the scanning can save up hours fixing the mesh later. Tub Final 16MB.stl (16 MB)
I tried the semi-auto fix method in Blender as explained in the other topic I mentioned.
Basically I had to split the part in four to use the Remesh Modifier so it wouldn’t crash; later I did some boolean to stick them together. I also send it to Magics and did a ShrinkWrap to get a better mesh. The final result got less details, but its watertight and 3D Printable. 12MB
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I also added some geometry to it in Blender (two cylinders and fixed one hole), but I am not a Hardsurfacing artist. Guess it’s a good idea to study it lol
After that also tried to get a NURBS solid in Rhino from this file and from others (have like 8.5GB of this stuff here lol). Unfortunately I failed, maybe zxys001 could help with that.
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Got like 40,000 surfaces. I need to check how to lower it before use ToNURBS. It’s pretty difficult to get a good quality SubD from the mesh, probably due to the propagation of deviation and also the lack of symmetry. Will try again next week.
Hello Dennis…when converting data from a 3D scan geometry it is always, 100% of the time, best to capture as much as possible in the beginning as there is a direct exponential 1:1 in terms of bad scan data to file fixing that needs to be done in post processing. What I would say is that whom ever did the original scan missed A LOT that, even if converted to a BREP model it will need a ton more file fixing.
Do you know if there is any additional access to the physical model?
This data has also been fiddled with a bit. It looks like someone started to try to clean it up, but obliterated some detail. Here’s one of the more obvious spots:
Notice the circled boss on the left, and how the corresponding boss on the right has been ‘covered over’, probably in attempt to fill missing data on the side of the rib that was in the shadow from the scanner.
I all reality it really should be taken back to the beginning and scanned again thoroughly. There’s just too much missing data to try and reverse engineer this properly.
