Fillet undercut

The course has been great and provides a great segue into the world of 3D modelling.

My Application: Trying to model an inlet manifold for a low port SR20 engine. There's not much out there for low ports and I don't believe ( but could be wrong ) any take into account a taper between throttle block and head inlet.

Objective: 3D Print in a medium that provides dimensional accuracy for test fitment and ultimately have it sinter aluminium or Carbon Fibre printed.

My question. I'm trying to fillet between a flange plate and inlet runner but every time I attempt to fillet between the two I get an undercut fillet.

I've tried - creating the runner body ( using lofting ) in a different direction / joining the two bodies / creating a new component. Fillet radius is 2mm and the closest the runner body is to the edge of the target body is 4mm.

At this point it's a pretty basic representation of an inlet manifold as I haven't modelled strengthening ribs, injector boss or outer flange for the throttle blocks, but I think you get the idea.

Any assistance would be really appreciated.

Hi Doug,

looks like a great project.

You can only add fillets between the surfaces of a single body. So the runners and flange need to be the same body.

When you use the loft tool you can set the operation preference down the bottom of the tool window to "join".

Alternatively use the combine tool under the modify drop-down menu to combine the bodies.

If you need to you can retain the original bodies as well.

Hopefully this answers your question?

Thanks. Connor. Thought I'd tried the single body prior to posting. Anyways. I joined them and can fillet some but not all of the junction between the intersecting bodies. I think I have a problem with my base geometry sketch for the inlet shape so will go back to basics and start over.

Thanks again. Doug

Fillets can be a bit frustrating as parts get complex. I've been battling them a bit with our SR20 billet valve cover i'm working on.

Have a play with different radius fillets. Even try variable radius type.

Or sometimes slight changes to the profile of the edge you're trying to round can help.

You'll start to get a feel for what works and what doesn't

cheers,

Connor