Editing Parts in Context from Assembly and alignment.

john_gentilin

I may be stating my problem statement incorrectly so I will be a little verbose here.  This discussion will reference V9 of this document, https://cad.onshape.com/documents/9ec3baa19294f3198f092b39/w/26baf85d5c38ccafe4ec1fc0/e/9e352b7a38551480396b76b2

In the Assembly, "Neck Assembly", I decided to change how the StepMotor<3> is mounted to the "Upper Neck Joint", from a side mount to a upper middle mount.  I moved the stepper motor in place, roughly, then edited the "Upper Neck Joint" as an in context edit. I wanted to grab the curvature of the motor and mount points, so I create a new sketch off the face of the motor, "use"d the existing lines and extruded'ed it. The new extrusion is now off center from the existing part because the placement of the StepMotor was not centered to the "Upper Neck Joint" to begin with,

My questions are 

1) Am I correct in that the assembly functionality does not provide the ability to align a part to a plane / surface / mate in the assembly ?

2) I would like to grab the center point of the derived sketch and move the context in place. i.e. when editing the part "Upper Neck Joint", in context to the assembly, I would like to take the center point of "Sketch 5" and make it coincident to the Front Plane and have that operation adjust the placement of the original context, maybe even have it update the position of the part in the assembly. 

I think I can remove the "context" constraint from sketch and center the sketch to the front plane, but that won't move the context of the motor in the sketch so everything will look offset.  I am trying to do this in V11, but I am having a hard time constraining the sketch.

Is there an easier way to do this ?

Thank you
-John Gentilin

john_mcclary

It looks like you tried to do In-context a few times before ending up with your result:


You may want to purge the unused ones or re-name them to make it easier to trouble-shoot

From what I can see, you may need to Update the context in the assembly,


Then Change the plane of Sketch 10 From "Right Plane" to The rear face of the step motor. that way if you rotate the assembly and update context it will remain parallel to the motor.

Then remove all of the dimensions you added for hole centers, etc.
Constrain the mounting holes concentric to the holes in the motor. (this is what in-context is for)
Then to get the center hole to line up, make that bottom quadrant point coincident to the motor.
Then add and dim's necessary to fully define the sketch (Make the lines Black)



Let me know if this helped
https://cad.onshape.com/documents/785e6ed144758aa408beabe1/w/a2290d81ac8b8125b015a5e8/e/cc8b80e2e456d68dc62eb880

john_mcclary

It looks like you tried to do In-context a few times before ending up with your result:


You may want to purge the unused ones or re-name them to make it easier to trouble-shoot

From what I can see, you may need to Update the context in the assembly,


Then Change the plane of Sketch 10 From "Right Plane" to The rear face of the step motor. that way if you rotate the assembly and update context it will remain parallel to the motor.

Then remove all of the dimensions you added for hole centers, etc.
Constrain the mounting holes concentric to the holes in the motor. (this is what in-context is for)
Then to get the center hole to line up, make that bottom quadrant point coincident to the motor.
Then add and dim's necessary to fully define the sketch (Make the lines Black)



Let me know if this helped
https://cad.onshape.com/documents/785e6ed144758aa408beabe1/w/a2290d81ac8b8125b015a5e8/e/cc8b80e2e456d68dc62eb880

john_gentilin

Wow, I did not know I had all those contexts. I think they are created when I am doing an Edit In Context, of a new part, but only defined the sketch and the session times out. I will try the context update. Thank you for the feedback. -John