A different type of array?

[JST]

I seem to be doing stairways at the moment. And things naturally change, which makes for a great deal of slogging through constraints, implementing changes.

So....

I cannot seem to find a way to do an array that consists of a series of parts which have a "horizontal" spacing, AND a "vertical" spacing.

I CAN make a rectangular array that populates a "block" of parts that is X number horizontally, AND Y number vertically, comprising X times Y parts. Not what I want.

What I want to be able to do is to populate an array that has X units only, spaced at a particular distance horizontally, and at a different distance vertically. To make, yes, a "stairway" type array.

I have not discovered how to do that, if it is possible. IS it possible? There seems to be no such option in the array window.

It seems as if it would be just an extension, or "option" within the existing array function. Not sure what it would be called, perhaps "stairstep array".

That would really help with this sort of arrangement, which is not limited to only actual "steps". It would make changes a simple change of one or two parameters.

Yes, one can choose to make a horizontal array, and then manually change only the vertical spacing for each individual pair, for instance (or the reverse) But that's still a lot of work, and assumes you know which spacing is more likely to change.

 

[HaroldL]

Well you can, sort of, by using the assembly Linear Pattern. The issue with that tool is that it does not allow you to pattern ONLY the selected item without making multiple instances. You end up having to delete everything that is not part of the stairway.

And here is the pattern with all the "extra" stair tread deleted. PITA


I'll bet that Development could figure this out in a heartbeat and have a toggle in the Linear Pattern tool to allow this pattern.

 

[MilesH]

All I can think of is doing a single array in the slope angle of the staircase.. You'd need to use trig. in the Equation Editor for the spacing....

 

[JST]

Yes, I had not thought of setting up the angle, and patterning along that. It's a decent idea, and would work. Yes, you'd need to do the angle, but that is not too bad if you know the rise and run you need. Sometimes that is known.

Problem is that the angle is often to some extent the unknown. With steel fab, any distance less than 1/32" (.75mm) does not exist, and 1/16" (1.5mm) is better. And there are statutory limits on maximum rise per step, as well as step depth, plus practical limits on overlap. So it often comes out to getting a decent round number for the step height, in 1/8" increments if possible. The angle ends up as whatever it takes to get that in cases where the exact "run" of the stairs is not critical.

So some fun with spreadsheets prior to setting up the angle. But still less things to change when (not if) the requirements change partway through.

Not bad as a "workaround". Thanks.

 

[bigseb]

Another case for pattern along curve.

 

[Dave Machock]

Here is how I did some, using an axis

 

[MilesH]

You're well ahead of me Dave

 

[MilesH]

Phew! Got there.

Rise and Run editable in Sketch 1.

No. of steps editable as Instances in Feature Pattern

 

[JST]

Woof! That's some interesting work for sure! Thanks.

I have not gotten that involved with the equation system yet. In cases where I need that amount of calculation I am more likely to set up a spreadsheet. But that is because I am much more familiar with spreadsheets than with the equation system in Alibre. It's pretty powerful, but needs a clear understanding of how it works, which I have not yet acquired.

Patterning along a line (or curve, in general) would surely be simpler to use. It would be a very good feature.

 

[NateLiquidGravity]

I've done stairs similar to @Dave Machock and @MilesH using the hypotenuse measurement and the axis. FYI with sketches now being available in assemblies and reference dimensions being available in the equation editor you can make stairway assemblies out of parts that will automatically adjust between the platforms.

 

[HaroldL]

Wouldn't you want the stairway to be an assembly?
The odd thing about the assembly is that the pattern won't update you need to edit the pattern.


Not that this file has one, but would it make sense to drive it with a Global Parameters file? That way you could control tread parameters along with rise/run from the same file.

(@NateLiqGrav looks like you beat me with the assembly reference.)