Split tool Lofted Flange

[Anonymous]

Hi All,

I have a tricky modelling task that I need some help with... 

I've created a multi-body sheet metal part with a lofted flange for a square to round transition (see attached file)

I'm using the Split command and a user plane as the split tool to make the lofted flange from two pieces along the shortest bend line (see Transition Split Plane feature in model).

The model is parametric with two key parameters OUTLET_DIA and FLANGE_ANGLE. The problem occurs when I change, for example OUTLET_DIA from 150mm to 200mm, the user plane loses all its inputs. I need to be able to change the key parameters without having to intervene and fix the plane each time. Any ideas how I can achieve this?

[Xun.Zhang]

Hello @Anonymous,

It depends on the definition of workplane (Transition Split Plane), it lost the reference point once modify the parameter to 200mm.

I don't know the design intention, it would be good if you can find a more robust way to setup the workplace to avoid the impact from upstream loft feature.

Hope it helps!

[WHolzwarth]

Here's my attempt (2018 IPT).

Fine-tuning is still needed.

[Anonymous]

Hi @Xun.Zhang 

I understand why the work plane is losing its reference point and that the way I have modeled it is not robust.

I was hoping that by posting, someone else would reply with a more robust way of achieving my goal.

The design intent is that the loft is split as shown below, and the INLET_DIA can be freely changed as desired.

[Anonymous]

Hi @WHolzwarth ,

Nice attempt, I think you might be onto something by modelling the parts with separate loft features.

The issue I see on your model is that the horizontal line that splits the round profile into semi-circles is constrained to the projected center point from the Flange Sketch (the rectangular profile center point)

The true convergence point of the Transition Lofted Flange is different. I can't find a way to reference it though without it failing every time the diameter changes 🙁

[WHolzwarth]

New attempt, looking better.

[johnsonshiue]

Hi! Another alternative is to create regular Loft Surface. Then use Unwrap to flatten it. This workflow would simplify the bends.

Many thanks!

[Anonymous]

@WHolzwarth  that looks better, splitting the semi-circles at the center point of the circle is closer to the "true" convergence point ("true" as in the point the bends would meet if created from a single lofted flange feature)

If anyone has an idea how to reference the "true" point the folds converge, please do share.

Many thanks.

[Anonymous]

@johnsonshiue  thanks for your reply.

Unfortunately I'm using 2018 so I don't yet have the Unwrap feature. Still not entirely sure how this would solve this problem though.