Help with Lofting

[kcoffield]

I'm still very much a novice and this file will probably emphasize that but I dont understand what is creating the problem with Loft 3. When I suppress extrusion 4 it displays fine but throws an error with extrusion 4 active. I'm trying to use the combination of features to create a machining surface and will eventually need to make loft cuts on the backside to creat that surface but have been stuck for quite a while withthis problem. What is it about extrusion 4 that's causing the lofting error?

Best,
Kelly

 

[DavidJ]

Changing the feature order around removed the error - may or may not be what you wanted to achieve...

 

[kcoffield]

Thanks so much for your help David. That worked. I have no idea why it worked, but I wish all my problems could be solved that easily . I was able to complete the model, generate the surfaces I needed, and generate the coorresponding CAM files. I should be able to cut the part tomorrow.

Best regards,
Kelly

 

[DavidJ]

Lofts are one of the trickiest things to get right, even after some massive improvements in the last few versions.

Sometimes the status message for a failed loft can give a useful clue (though often it won't be very informative).

 

[kcoffield]

Lofts are one of the trickiest things to get right, even after some massive improvements in the last few versions

I'm sure I'll be back in the near future for more advice there. I have several V8 automotive intake manifold projects that required lofting the runners from shapes in diffrerent planes along a centerline spline. My previous efforts to loft along such centerlines were not successful and neither were some of the efforts of the more accomplished folks here. I'll ressurect those threads in the near future.

Sometimes the status message for a failed loft can give a useful clue (though often it won't be very informative).

It think it said something about incompatabilty of tabs and tangency. I searched it the online help but no joy. It mayhave been because the one of the lines on one sketch was coincident with a portion of another sketch used for different lofts and/or extrusions. I should have cut and pasted the error message in my post but once I got by it, I was more interested in completing the modeling and CAM work that produced the cut file attached below. It's a drop base automotive air filter on an oval carburetor. It's approximately 21" x 8", has 3/16"-1/4" wall thickness, and will be cast in aluminum using evaporative pattern casting methods.

Thanks again for your help.

Best,
Kelly