Dimension between two sketches, or between face and plane - how to?

[Anonymous]

Noob q:

How can I enforce a specific distance between a plane (or face) and another face?

See attached pic.  

I'm making a simple wheel rim, the center hex (hub) is suspended at the moment (haven't drawn the spokes yet), and I need it to be a specified distance from the edge (bottom plane).  Currently the hex is extruded with an offset from a sketch on that bottom plane (raising it up 10mm), but I want to enforce a distance in the sketch rather than an offset in the extrusion/body.

The dimension tool is causing the following problems for me:

1. Can't seem to select a plane, edge or point depending on what body or sketches are in the way (blocking view, annoying, but resolvable)
2. Doesn't seem to apply to a face
3. Cant select a plane to set a dimension to
4. Can't seem to set a dimension between two different sketches, even if I do try and select an edge or point in each

I'm new to Fusion 360, but not to CAD in general.  The biggest hurdle moving to 360 seems to be just selecting things and understanding which tools apply when (and why they don't when they dont).  Grrr.  In this case specifically, I am likely trying to select and apply things for the Dimension tool with the wrong approach.  Anyway, tips on this much appreciated!

[jeff_strater · Accepted solution]

Yes, this is correct.  The sketch dimension tool is only applicable to 2D geometries within the sketch, and that lie in the sketch plane.  So, you will not be able to control the location of the hub using a sketch dimension.  Well, actually you can, if you create a second sketch, but that's a bit complex and probably not the best workflow.

Instead, you can control this a number of ways, all of them completely parametric.  Here are just a couple:

1.  If your hub is always in the exact center of the wheel, you can use a midplane to position a sketch plane:

This method will always position the hub in the center.

2. if the hub is asymmetrically positioned with respect to the wheel, I would use an offset workplane to create the sketch plane.  You can modify the parameter that controls the position of the hub using the Parameters dialog:

There are many more options, including having the hub be a separate component and using a rigid joint to position the hub (if in the real world the hub is a separate component, this might make sense.  And so on...

I'm sure you will get many more options offered here

Jeff

[SaeedHamza]

Hi,

Here is a screencast to show that you can use dimension between different sketches or even a sketch and a body, but that won't allow you to change their position by changing the value of the dimension, the only thing that will change is the position of the sketch you are in using the dimension

https://knowledge.autodesk.com/community/screencast/c1db67ab-c37e-4410-8667-4ca56ba21de6

Regards, Saeed

[SaeedHamza]

Here is a way to create your sketch where you want without extruding it from object

https://knowledge.autodesk.com/community/screencast/25aca5e2-1ec1-438e-8b9a-0128305b1425

Regards

[Anonymous]

Offest Plane is what I needed.  This is a very cool feature, thanks!  I clicked accept on the first to suggest it, but you all had pointed me in the right direction, thank you!