Hi Alex,

It looks like the problem I mentioned before: the Sweep command in MoI (which the pipe script is based on) has limited accuracy. I examined the surfaces in both STEP files in MoI using Construct > Curve > Iso and then checking the properties of the generated curves. The isocurves of the solid exported from SolidWorks are very close to being circles and so are recognized as circles by MoI which shows a diameter value for them in the details area in the upper right corner. Doing the same thing on the "TEST ARCS MOI EXP.stp" shows that the curves aren't as close to being true circles, and so MoI just shows bounding box dimensions rather than a diameter value:



Have you tried exporting a STEP from SolidWorks without doing "lock tangents"? Is Pipebend still happy if "lock tangents" is skipped?

Another way to see what's going on is by opening the STEP files in a text editor and doing a text search. The SolidWorks file is made up of TOROIDAL_SURFACE entities. The MoI file just contains general freeform surfaces.

- Peer

Thanks Peer,

Your CAD forensics are impressive - all makes sense I was wondering were PIPEBEND was collecting the bend info.
I did think there was an underlying structure difference between Parasolid and Open Nurbs and the way the surface was created.

I tried a part from SW without Tangent lock and same curve from Moi and that imported AOK into pipebend so yes that curve pathway is tangent - but have a look at the MOI Fillets file that was a series of polylines with fillets applied and then shelled. That solid imports into PIPEBEND aok so strange it structures the surfaces in some instances in same fashion and then in other style that PIPEBEND cant read.

Really appreciate the insights.

No help from this member of the peanut gallery on the problem at hand, but just to say that I'm looking forward to pics once your new sculpture begins to come to life Alex!

--Larry

Hi Alex,

Re:
> I did think there was an underlying structure difference between
> Parasolid and Open Nurbs and the way the surface was created.

I doubt this has anything to do with Parasolid vs OpenNURBS. Both are capable of analytic representation of a torus.

Re:
> That solid imports into PIPEBEND aok so strange it structures the
> surfaces in some instances in same fashion and then in other style that
> PIPEBEND cant read.

I'm guessing that Pipebend is smart enough to look at general surfaces and check whether they are sufficiently close to being a true torus. The key word here is "sufficiently" because if MoI and Pipebend use different tolerances for "close enough" then sometimes they are going to agree, and sometimes not.

One thing you could do is look through the Pipebend settings to see if there's an import tolerance setting somewhere. If there is, you could try setting it to a larger number like 0.03 mm.

- Peer

Thanks again for input definitely shedding some light on the internal process of file translations.
I checked in Pipebend and yes there is a option for loosening the tolerance in the import I will have a play with that and see if that gets all the MOI files flowing in.

Just getting the next project ready to start bending 90m of 20mm pipe bent and welded into one continuous pencil style drawing.

Modelled in Moi should be completed in the next couple of months.

Neat design Alex, where will it be installed?

--Larry

Thanks Larry - will be installed in September on Currumbin Beach - Gold Coast Australia.
Almost there working out the mechanics of bending this much tube ill post some production shots as it comes to life.
No rest for the wicked!