Dimensions Over Constrain Sketch By Default?

larry_hawes

Not sure how to ask this and I think I see what is happening but it's bugging me to no end. Sketch a rectangle, extrude. Sketch another rectangle that aligns with outer edges of previous rectangles and is constrained coincidentally at expected lines and points. Enter dimensions, cause I don't know what else to do complete the sketch, and the sketch is over constrained because it really doesn't need at least one dimension as it is already constrained coincidentally along that dimension.

Can the second rectangle be created without dimensions? Or some simple method to keep this kind of sketch from being over constrained?

http://www.youtube.com/watch?v=6stKRJmbtP4

steve_shubin

@larry_hawes

I thought maybe this is an interface thing.
Maybe it’s different on the desktop then it is on the iPhone.

I went and got my MacBook and opened Onshape

Below is the screen capture

I entered the horizontal dimension, and there was no need to enter the vertical dimension as it was constrained to that of the cuboid. Then I deselected the tool. And there was nothing overconstrained

steve_shubin

@larry_hawes

After sketching the rectangle on the face of the cuboid, deselect the Centerpoint Rectangle Tool in the tool bar before entering any dimensions

larry_hawes

...and then manually add dimensions? Seems just a little bit more awkward. The problem is, of course, that the one dimension that spans and snaps coincidentally to the existing rectangle (in this case the 9.5") just does not need to be there and can easily be deleted after the sketch becomes over constrained but seems awkward at best. Is this just simply the way Onshape works in this case?

steve_shubin

@larry_hawes

In the above GIF, I answered your first question which is can the second rectangle be created without dimensions

Think of a constraint as like an anchor. So if I snap (constrain) the bottom horizontal line of the second rectangle to that of the cuboid, and if I constrain the top horizontal line of the second rectangle to the top line of the cuboid, and then if I try to add a dimension between those two lines, the program is going to say no no no. The bottom horizontal line of the second rectangle and the top horizontal line are locked in place you cannot move them. If you want to move one of those lines of the second rectangle, you’re gonna have to release one of those constraints

If you want to add a dimension from the bottom horizontal line to the top horizontal line of the second rectangle, then when you are sketching that second rectangle, don’t allow it to snap to one of those horizontal lines on the cuboid

You can add a dimension to the width of the second rectangle and it will not go into overconstraint, as long as you don’t snap both vertical lines of the second rectangle to the vertical parts of the cuboid when sketching the second rectangle

steve_shubin

@larry_hawes

I thought maybe this is an interface thing.
Maybe it’s different on the desktop then it is on the iPhone.

I went and got my MacBook and opened Onshape

Below is the screen capture

I entered the horizontal dimension, and there was no need to enter the vertical dimension as it was constrained to that of the cuboid. Then I deselected the tool. And there was nothing overconstrained

larry_hawes

Thanks Steve, I could clearly see why it was being over constrained with the vertical dimension but couldn't see an order of operations that would release that vertical dimension. Your solution worked perfectly. Thanks. I sometimes sketch/build simple boxes and line up edges that were constantly being over constrained in the manner shown. I will remember this method and thank you again.

steve_shubin

@larry_hawes

My pleasure. That’s good news to hear that it worked out Larry