How does one force a "horizontal constraint" on a dimension?

[maula006]

So I have the following scenario: A sketch of four wheels.

They have the following characteristic:

• Wheels can have different heights from the ground (based on an offset)
• Wheels can have different diameters
• The placement of each wheel is relative to the first wheel
• The distance between each wheels is the wheelbase.

So if there comes a scenario where I want to make the middle two wheels smaller and the first/last wheels off the ground a bit, I want the wheelbase between each wheel to remain!

However, what I have currently doesn't maintain any sort of horizontal constraint! So if the wheel sizes are changed... The dimension just "bends over"!

I'm sure there's a solution to this, but I'm not sure how to achieve it.

Do you have any suggested way on how to do this?

Here's a sorta expectation vs reality:

P.S. I'm trying to replicate a "rockered" setup for inline skate wheels using parameters.

[g-andresen]

Hi,

Define a tangential dependence between the wheels and the ground and then the horizontal distances.

günther

[TheCADWhisperer]

Can you File>Export your *.f3d file to your local drive and then Attach it here to a Reply?

[maula006]

A tangental constraint means that all wheels touch the ground right?
Thing is, in rockered setup (i.e. the second image) only two wheels touch the ground at any given time.
Kinda why this is a bit troubling...

[TheCADWhisperer]

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@g-andresen wrote:

Hi,

Define a tangential dependence between the wheels and the ground and then the horizontal distances.

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Not all Tangent.

[jhackney1972]

Sure would have been nice if you had attached your model so the Forum users do not have to build one.  As @g-andresen mentioned, I created a Screencast to prove it.

[davebYYPCU]

During the dimension tool, select items, right click, set horizontal.

Might help....

[TheCADWhisperer]

@jhackney1972 

Not tangent to ground.

[TheCADWhisperer]

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@maula006 wrote:

So if there comes a scenario where I want to make the middle two wheels smaller and the first/last wheels off the ground a bit, …

P.S. I'm trying to replicate a "rockered" setup for inline skate wheels using parameters.

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Construction lines.

[maula006]

Alright. I hope I did it correctly

[maula006]

Sorry about that! I thought the solution was something simple, so it didn't cross my mind...
You'll be able to see the file when you scroll further down below.

Though I should note that the tangency is not applicable in this situation as it is possible that only some of the wheels may be touching the ground at one time!
It's a "rockered setup" in rollerblades.

[maula006]

But how do I apply the construction line to the dimension?

[maula006]

No can do I'm afraid 😕

[davebYYPCU]

Not edit dimension, 

when creating Dimension, the Menu will have it.

Will check the file, as being a rocking motion, I can see a rabbit hole.

[jhackney1972]

Something like this, model is attached.

[maula006]

I do see how your solution works, but I think that's far too restrictive for my application.

There is no restriction that forces the setup to have rockered setups just the middle wheels touching the ground.

https://skating.thierstein.net/Knowledge/Inline_Skating_Rollerblading_Knowledge_Rockering.html

There exists many rockered configurations besides the normal setup, such as Anti-Rocker (front and rear touch the ground but not the middle) and HiLo (basically skates lean forward).

I understand the idea behind your concept, but unfortunately it won't work for my setup, sorry (at least in a way that's easy to modify via parameters afaik).

[davebYYPCU]

Edited:

I just read the pictures.

[maula006]

Ok so... I've tried applying what people have suggested me, and tried the following solution.

I created construction lines connected to the midpoint of the circle that have a vertical constraint, and made a dimension between the appropriate construction lines (the line itself and not the tip).

It seems to respond well to changes in the wheel structures, even extreme ones:

But I have a feeling that this is a stopgap solution more than a permanent solution...

I am really new to Fusion 360 so I'm not sure if this is the best solution to use.

What do you think?

[davebYYPCU]

White, Blue and Orange articles should keep you awake at night.

Keep them all black.

Tie the orange vertical lines to the artificial ground.

Might help....

[maula006]

You mean tie the construction lines to the origin?
I made a construction line in the axis origins if that counts... Though, those are orange lines themselves.

What's wrong with construction lines?