Can't replicate bike frame tutorial

[landslide1]

I can't get an extruded body to seperate into two parts. I have got simmetry and have tried the ALT key but the body stretches out without splitting into two.

https://youtu.be/OphzbTt4rKo?t=452

I have attached a simple body That I have tried to split the narrow end but it makes it wider.

[jhackney1972]

Please attach your model from Fusion 360, what you are working on showing the issue.  If you do not know how to attach your Fusion 360 follow these easy steps. Open the model in Fusion 360, select the File menu, then Export and save to your hard drive. Then use the Attachments section of a forum post to attach it.

[landslide1]

I have added a simple shape not exactly like the youtube tutorial but all I want is to transition a round pipe into two forks like what the presenter does in the tagged tutorial above.

[landslide1]

I achived what I wanted by stretching the shape wider. I then inserted edges along the simmetry line and deleted the faces down the middle.

I then used bridge to seal the open sides.

it worked but has many steps when the tutorial I linked does it in one.

[jeff_strater]

The ALT key is the trick.  If you select faces in Edit Form that are just on a single side of the symmetry line, ALT-drag in Edit Form will do the separation.  It's hard to see in that tutorial, because the view never changes.  If you select faces on BOTH sides of the symmetry line, then the split will not happen.  Screencast:

[TrippyLighting]

I would suggest you take a look at other tutorials.

The first thing I look at in a T-spline tutorial is whether the author models in box-view mode at least a good part of the time, or at the very minimum inspect the model in box view mode.

Experienced T-Spline and Sub-D modelers model 80-90% in Box view mode and use smooth-view mode to inspect the model.

This is an Excellent T-Spline tutorial: