AUTOCAD GURUS - here's a problem for You to solve...

[palibebeh]

hi all.

i've stumbled upon this problem, while trying to draw something in autocad.
let's say we have a path (an ellipse), and we want to draw a staircase along the ellipse.
to make things simpler - we will only draw lines to represent each step.
now - how to copy the lines (steps) along the path (ellipse), so that the lines would not only be evenly spaced (by given value) but also rotated accordingly?

i have no idea how to do that, in archicad it's painfully simple - unfotunatelly i have to do this in autocad...

thanks guys

[dbuchhofer]

If its simple in one program, and fairly easy to convert, why fight with it on autocad?

I dont have any real answers, its been like 13 years since i've done any serious cad lol

[dlparisi]

It's pretty simple in acad too. Convert your step (line or whatever) to a block and use the measure command on the ellipse. Choose "block" and "align block with object". This is if you want a given value for the space between steps but will give you an odd step at the end. If you want all equal spaced steps use the "divide" command instead.

You may have to rotate the block definition to get it to align correctly to the ellipse too.

[palibebeh]

well unfortuantely it has to be done in autocad....

thanks dlparisi! it works, but:
i managed to convert my object to a block, but i don't know how to rotate the block's definition. and as a result the blocks are all rotated 90 deg to what they should be...

[dlparisi]

Well you can explode the original block and just rotate everything correctly and choose the same origin point when you redefine the block and all of the other blocks will rotate too. Or you can double click on the block (assuming it's a newish version of autocad) to edit the block (just hit OK when he dialog box opens). It'll open the block editor - rotate all elements around 0,0,0 (this is the insertion point of the block while in the block editor) and then just click "close block editor" at the top of the window to save changes and redefine the block.

[dellis]

I would use the spacing tool in MAX...then export as a dwg and then not tell anyone!

[mikeh]

here's another way to get it done.
1. use the divide command on the ellipse.
2. draw each step from the center point you like best.
3. offset the ellipse into the steps and trim the steps with the offset.
mh

[palibebeh]

thanks guys!

yeah i know that it would be much simpler and faster to do this in max or archicad, but it had to be done in autocad. the reason for this is that i was helping my friend with one of her projects, and she's working mainly in autocad...

but thanks to you guys the problem was solved
the only issue now is that we are not able to rotate the steps to be perpendicular to the spline in their intersection point/pivot. i think that the best way to do this is to somehow draw a tangent in the pivot and then rotate the step to be perpendicular to that tangent. but i still don't know how to draw a tangent......

[dlparisi]

the only issue now is that we are not able to rotate the steps to be perpendicular to the spline in their intersection point/pivot. i think that the best way to do this is to somehow draw a tangent in the pivot and then rotate the step to be perpendicular to that tangent. but i still don't know how to draw a tangent......

Can you explain a little more what you're trying to do?

[palibebeh]

ok

let's say we have the spline, along which we are copying the 'steps' (blocks).
when done properly - using your method - all steps will be aligned to the spline.

BUT

the angle is NOT 90deg. i have to manually adjust the angle by editing block's definition, but i don't know how to make the step/line to be perpendicular to the spline in the point, in which it is attached to the spline - in other words i want to have my 'steps' (blocks) perpendicular to the 'wall' (spline). how can i do that?
what's the method to align an object to be perpendicular (90deg) to a given point on a spline?

[dlparisi]

Still not really getting you. Are you saying you can't rotate the block correctly? You need to rotate the definition of the block (i.e, redefining it) and not just rotate the block. I've attached a dwg file that is how you wnat it I think, right?

[voltron7]

I would do something along the lines of what mikeh suggested...being mindful of the base points you choose in some of the steps...okay, sorry, that's all I got now, totally burnt-out on AutoCAD!

[rmejia]

Maybe you could upload a cad file to see what you are trying to do. For steps or equal space lines (parking lines or stairs) along a curved path I would:
1. First line - Draw a start line from the center point of the path (curve, ellipse, arc, etc...) to a point perpendicular to the path.
2. Offset that line to the desired spacing (for the steps)
3. Second line - Draw a line from the intersection of the offset line to the path line (perpendicular)
4. Mirror the first line using the second lines start and end point, and then keep doing that, mirroring the line before last using the last line as the mirror line.