Locking

[rubidge]

As a newcomer to Revit (from Autocad) I have not yet got my mind around the concept of Locking dimensions, or objects to each other. I understand their purpose and operation in specific situations, but I would like to hear what people might say about LOCKING in general. Or a strategy for locking.

Does one wait until one wants to stretch a wall and then go back and lock all items where one wants to keep the same relationship, or do you lock items as you go. How do you know what you might need to have locked?

What about relationships between layers/levels/floors?

What thoughts?

[Dimitri Harvalias]

Lloyd,

Locking is a powerful feature of Revit but it does have its pitfalls. By no means a complete list of considerations, here goes.
1. Locking objects adds overhead to a project file. Each time a change is made the software must check to be sure that any locked relationship is not being affected.
2. If too many objects are locked the model can very quickly become over constrained, ie you can't move one thing without affecting the constraint imposed by another lock
3. Revit has a certain amount of built-in 'glue between objects. For example, once a wall end is joined with another at a corner, if one wall moves the other will move it.
That said,
1. Only lock objects that require a relationship to be maintained. Once critical components of the building are established such as elevator/stair cores, it's not a bad idea to dimension them and lock them to grids.
2. Dimension and lock grid lines where possible. This prevents inadvertent moving of grids.
3. Locking exterior wall relationships to grid lines is a great way to control a project if the program is not nailed down. Move the grids, the walls move.

I'm sure others have more to say on the subject but I think the best bet is to work through a project and it will become pretty clear what your needs will be.
Good luck

[irwin]

Lloyd,
2. Dimension and lock grid lines where possible. This prevents inadvertent moving of grids.

If your goal is to keep an object from moving it is better to do this using Lock Objects (the push pin icon in the tool bar), rather than by locking a dimension. If you lock the grid line element itself then you can't accidentally move it. If instead, you dimension it to another grid line and lock the dimension then you CAN move the grid, and it will move the other grid, so this isn't a good way to keep from accidentally moving something. Also, the performance overhead is much greater for locked dimensions then locked objects. Locking an object just says "don't let this move", while locking a dimension says "maintain this relationship between these two things" which is a much more complicated constraint.

[sbrown]

My rule of thumb especially in worksets environments is to never lock anything until you find you need to. For example, you create a wall section and place all your detailing, in theory you can lock all the detail components to the wall geometry so if the wall moves the detail items go with it. However in practice, the time it takes to lock all those and the potential problems that could occur make me decide to move them manually if the wall ever moves(they will remain in the view and can easily be selected and moved back into place.

Some exceptions to this rule are imported DWG's or raster images being used as backgrounds. and the occassional align and lock of an object.

the problem as pointed out before with locking dimension is it can ripple thru your project, lets say you have a stair shaft wall that goes 3 stories, in the basement you have a hall adjacent to the the stair wall that you want to maintain 5' clear so you place a dim and lock it. then on the 3rd floor you have a hall that you want 8' so you lock that dim. Well if you ever move the wall on the 3rd floor, you will move the stair wall and the lower level hall wall. This can spiral out of control easily if people are working on multiple levels and don't know what constraints are in place throughout the entire model.

[Dimitri Harvalias]

Irwin, good point and in fact that is what I do more often than actually lock the dims for grids. Thanks for setting it straight.

[nicholas_baum]

Lloyd,

Thanks for starting this thread. I am a newbie also and have found myself in a situation where I am trying to move a foundation wall and the wall above is also moving. I cannot see how it is constrained.

Maybe someone could advise me to the best way see ALL the constraints and to unlock these walls. I have looked at the dimensions to the walls and they are not locked. I have tried to highlight walls and used "activate dimensions" to see constraints and I believe I have removed all of the EQs, constraints and locks -- but still walls move together.

Thanks,
Nick

[nicholas_baum]

OK. I should have thought of this work-around before:

I made copy of the foundation wall a few feet away then deleted the offending foundation wall and moved the copied one to the correct location.

It was simple fix in this case.

Nick

[irwin]

When you select the wall, it should show all locks that affect that wall.

If not, some other workarounds are:
- Select the Wall. Cut. Paste Aligned | Same Place.
- Move the wall using the disjoin option, then move it back.