Beam length changing after adding holes

[CADNoob96]

Hi there, 

Pretty new to Revit and I am trying to model an aluminium frame using a mixture of beams with different sections/profiles assigned to them, as well as modelled in place components. 

One issue I am finding when modelling beams, is that after I create holes using the Contour Cut command in the Steel toolbar (note I found I was having trouble using the Hole command so used the Contour Cut command instead), the beams sometimes end up changing length and snapping to the centreline of the member that is crossing its end. 

I have attached a drawing where this has occurred - the two channel sections that have holes in the top flange are supposed to only span between the faces of the RHS members at either end (such that they can be welded to the face of these members). Following the addition of my holes, the beams now are showing as spanning from the face of the perimeter RHS, then terminating at the centreline of the internal RHS that is adjacent to the vertical SHS. 

Can anyone shed any light on why this may be happening and how I can avoid it? 

Revit Version 23.1.20.70

Thanks for any assistance. 

Tom. 

[msgambelluri]

ok this model has many problems.

the families are not working properly. try to edit them and you get errors.

also the behavior should be as shown when you model beams on the same level the centerlines (worklines) are allowed to go to the centerline of the supporting beam. the physical beam will autocut back as shown

I recommend you consider "practicing" modeling some starter revit structure beams in a OOTB template with OOTB structural beam families so you could see the true behavior then reevaluate your model.

Thanks Marcello