Pattern with reference

[terrynicholasj]

Hello, 

I've been posting quite a bit lately so thanks for all the help. 

I've been working on some parametric models for some furniture as an exercise to learn fusion 360 for my intended application. I started with a basic bookshelf and am really happy; I can modify all of my (extensive) parameters without breaking the model, and even managed to fix everything in place so that the whole shelf moves width/length/height, and adds/removes shelves as I modify those dimensions (very beginner-like, but it's taken me some time). 

I'm trying to replicate my success with a "ladder shelf". I've created a sketch (https://a360.co/3bbf1cj) where the first two shelves stack directly over each other, but where subsequent shelves will "step" up to the top (e.g. at every 18 inches). 

Starting at what is (currently) the top shelf, I want to create a rectangular pattern that follows the leg, and so that as the shelves go up they get less deep (i've attached a screen cast). 

If I could use boolean functions in the formulas I think I could make it work, but have not been able to math my way around the problem (or use any other fusion tools). I've also attached a screen cast just in case that helps... 

I understand that I could make each shelf individually with certain parametric features, but I wouldn't be able to get the addition/removal feature like I have in my other shelf (I pasted that one here too, just as an example; it's just a model of the ikea bookshelf next to my desk [https://a360.co/2OnGPjJ]) 

Does anyone know if what i'm trying to do is possible?

[lichtzeichenanlage]

Here is no screencast.

[terrynicholasj]

Oops I forgot to click insert. Here it is! 

 

[lichtzeichenanlage · Accepted solution]

I see what you want to do, but you can't do that in Fusion 360. Patterned elements are always exact copies. 

[g-andresen]

Hi Nicholas,

When designing shelf ladders with Fusion, I think rectangular patterns are more disturbing than useful.
With the manageable number of shelves, a parametric construction with standard elements is easier to realize.

parametric shelf ladder
The prerequisite for this is, of course, as almost always, a completely defined sketch.

The prerequisite for this is, of course, as almost always, a completely defined sketch.
I also think that extensive calculations of variables, e.g. with angle functions and phythagoras, are not necessary.
In the appendix you will find an appropriately modified sketch.
In the sketch I first set the angle and height of the system and then defined further parameters. I did not need calculations for the parameters I inserted.

günther