Crash after changing sketch constraint.

[Tinkefu]

All those datum planes are essentially useless because they merely attach to the previous elements. The model is therefore quite fragile.

Gene

Ok so I should not be using the datum planes? I really wasn't sure. I watched a few tutorials where it said to use them, then others where it wasn't. So should I not use one if I'm just putting a new sketch on an existing plane?

[chrisb]

No need to delete PartDesign Fillet features since 0.17, they can be edited and the edges reassigned.

In general you are right, but with the complicated and rather cumbersome deselection mechanism it can become difficult, because the fillet can all of a sudden be assigned to a tiny edge which you have to find.

[GeneFC]

Ok so I should not be using the datum planes? I really wasn't sure. I watched a few tutorials where it said to use them, then others where it wasn't. So should I not use one if I'm just putting a new sketch on an existing plane?

Datum planes can be very useful for two primary reasons.

First, they can be placed in any location and orientation, and that is often very helpful.

Second, they can be made independent of underlying objects, and that helps prevent breaking the model when some parameter is changed.

Simply adding a datum plane on top of an existing face, for example, accomplishes neither of the two reasons noted above.

Some tutorial authors are "datum plane happy", meaning they use them for everything. Thats OK, but not necessary. However, it is important to avoid the trap of simply attaching a datum plane to an existing object.

Gene

[Tinkefu]

Ok so I should not be using the datum planes? I really wasn't sure. I watched a few tutorials where it said to use them, then others where it wasn't. So should I not use one if I'm just putting a new sketch on an existing plane?

Datum planes can be very useful for two primary reasons.

First, they can be placed in any location and orientation, and that is often very helpful.

Second, they can be made independent of underlying objects, and that helps prevent breaking the model when some parameter is changed.

Simply adding a datum plane on top of an existing face, for example, accomplishes neither of the two reasons noted above.

Some tutorial authors are "datum plane happy", meaning they use them for everything. Thats OK, but not necessary. However, it is important to avoid the trap of simply attaching a datum plane to an existing object.

Gene

Thanks Gene. Rebuilt without all of those planes and it went much smoother.