Sketch dimensions with Workplanes

[GH80]

I would like to use Workplanes a little more in my model, as I am having problems with sketches failing when the model is changed slightly. I guess this comes down to the way the original parts have been modeled - dimensions for features taken off other features, which are not necessarily constant.

I have found it possible to project the workplane on the sketch, although this does not constrain the projected plane, it is free to move around. Kind of defeats the purpose.

Does anyone have any suggestions, or possibly topics which I could research a bit more? Ideally I would be looking to insert a number of different datum points in each part, which I can sketch dimension groups of features off.

Inventor 2013 sp1

[Ryan.Martinez]

The origin planes are you friends. try to base everything off those and it will help to minimize problems when you change sketch dimensions. Can you post an example picture or something or what you are trying to accomplish?

[GH80]

I have attached a door frame component. I would really like a pair of work planes in each part, shown as planes 4 and 5. We have dozens of sketches for hardware components (not in the model shown), and the dimensions are all based from the planes shown. Some door leaves are not equal in width, so mirror or taking the origin as the mid point is not really a viable option. I would like to modify the end parts of the frame in future without effecting any other components.

If I have planes set at the given point and all sketches dimensioned from each plane, it will be the same for each of our design models, which would drastically cut down the ammount of work involved maintaining or creating new features (all part and feature selection is driven by ilogic). If I have to dimension each sketch from just one origin point, it will involve alot of formulas for dimensions, which can be done, but it will get messy and bloated.

Suggestions welcome! Thanks.