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Positioning in Assembly

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careyc

Mechanical
May 18, 2005
25
I can't get components exactly where I need them in the assembly. I tried using the move/rotate/freeform move function, but it seems to limit movement to a single axis. It would be great if I had unconstrained movement on all three axes so I can precisely position/rotate the components. Am I missing something?
 
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Sorry, forgot to mention I'm using V15. I'd appreciate any help!
 
When you select the part to move/rotate/freeform, where you select and drag limits your motion.

I typically prefer to select move or rotate, click on the axis to translate or rotate about, then type in the value.

Any reason you can use assembly relationships to locate the part?

--Scott

For some pleasure reading, try FAQ731-376
 
Thanks for the advice, but the component still doesn't move the way I want it. Do I need to specify the base coordinate system or anything like that?

 
Why don't you use create in place or partcopy?
and place (using partcopy) the new part which dragging with crtl pushed down?

Henk
 
Careyc,
Can you explain exactly what you're trying to do.
Are you trying to position parts without relationships to other parts or are you just trying to move parts ?

There are several different ways of positioning parts in an assembly :-
1. Using part faces or ref planes relative to the assembly ref planes.
2. Using part faces or ref planes relative to other part faces or ref planes.
3. By grounding the part and then using the occurrence properties to set position/rotation
4. Using co-ordinate systems.

You can't use the move command on parts that are fully postioned.

bc

 
I'm not very familiar with Assembly, so I think I'm missing a few steps. I drag in the component I want to assemble and use relationship options to place it. The component is like a swinging door on a base plate. I used axial, planar and other options to get the door's axial swinging point to the corresponding point on the plate. It goes in, but it's never exactly the way I want it (slightly off in the y-axis, rotation, etc.) It seems all I need to do is manually move it into place, but I have mixed success with that. I don't know any other way to do it, such as occurance properties or partcopy.
 
How many degrees of freedom have you satisfied?

Are you trying to rotate about a point or an edge?

Sounds like you need to add some planar aligns (or angle) relationships and make the planar aligns "floating" to remove the remaining degrees of freedom or to control manual motion in the direction(s) you're expecting.

--Scott

For some pleasure reading, try FAQ731-376
 
OK careyc,
There are obviously different ways of doing it, but this would be my preferred way.

1. Axial align between pivot point on door and pivot point on base.

2. Mate relationship between bottom of door and base plate - set the mate distance to give your required gap.

3. Angular relationship between front of door and front of base plate. This will let you set the door at different positions from open to closed.

If you are not sure how to apply the relationships, have a look at the assembly tutorials, and then if you still have difficulty post on this site and we can help you through.

Good Luck, let us know how you do.

bc.
 
Thanks. I'm starting to get it, but the assembly I'm trying to put together is somewhat complicated because there aren't any distinct points to attach the components to. The door has a cylindrical axis to pivot about, but the base plate only has a slot that is supposed to accept a round pin. There's no distinct circular geometry or axis to mate to the door. Plus, all the planar surfaces are at odd angles from each other, so there's no parallel surfaces to mate either. I can't find anything in the help guides that work.

I just used the Mate option to move the door into the grounded base plate. The door is sitting just to the side and above the space that it should fit in. I manually moved the door into place along the x and y axis, but I can't move it down into position along the z axis. It seems locked in that aspect. I'm trying to assemble the parts for display purposes only. I just need everything to be visually in place.
 
careyc

You could use the Surface command to create a cylindrical surface feature on the base plate, with this it's possible to align the door with axial align relationship. In V16, you could sketch a circle and align it with other parts, I'm not sure if it's possible in V15.

HTH.

fwc

 
You don't need a cylindrical surface to create an axial align, you can use a circle or point.
When you create the slot create a sketch first and put a point at the centre.
Alternatively, as you already have the slot, create a new sketch on the same plane as the slot profile and put a circle or point at the centre.
Then when you do the axial align you can select the 'display part sketches' option and select the point.
An implied axis will be displayed, which you accept.
As for the other mate/align relationships, use the part base planes or create new reference planes in your models.
 
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