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Bill Tillman

Sweep Me Not

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Bill Tillman

Can anyone tell me why I cannot sweep this one? The rectangular object at the bottom of the stairs is going to be the handrail. I have created a spline for it to follow up the stairs. But when I try to sweep it along this path, it will not work.

SweepMeNot.dwg

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BIGAL

I could be totally wrong here but I took a different approach and made a rough 3dpoly from your spline values but shape was weird ? Added a circle and extruded ok.

 

You may have to do a 3d poly with straights and arcs. Need to set up some UCS's so can flip to correct plane adding section and fillets.

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Dadgad
I could be totally wrong here but I took a different approach and made a rough 3dpoly from your spline values but shape was weird ? Added a circle and extruded ok.

 

You may have to do a 3d poly with straights and arcs. Need to set up some UCS's so can flip to correct plane adding section and fillets.

 

That is how I would do it too, BIGAL. :beer:

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BIGAL

Had a bit of a google search and could not find any easy way to do, Revit and Architecture have handrails. One way is to make each section on planar level extrude then use a union or fillet to join together. The riser rail meets the curve at a common TP but you actually need a tiny radius equal to rail size. Its almost a lisp type answer rise run fillet and keep creating. I am sure if I am wrong about this better 3d people than me will jump in pretty quick.

 

Look at the image, union the riser to the horizontal rail

ScreenShot086.jpg

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Bill Tillman

Thanks all. BIGAL, I too found that unless I broke the polyline up into sections I couldn't get this to work all the way up. The trouble still is in the upper left corner when you look at this in plan. The handrail elevates across the top of the plan view by 16cm thus when the SWEEP gets to that 90° corner I hit the wall with AutoCAD trying to rotated the rectangular shaped handrail. A round one will work fine because it's symmetrical along all 360° of it's profile. As I understand it, other versions of AutoCAD can handle this twisting if you will. But AutoCAD Professional does not. Anyway, this gets me close enough for this project. Not building a Swiss watch, just a handrail.

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Bill Tillman

ROBP: Thanks but it appears you're using MEP 2018, vs mine which is AutoCAD 2014 Professional. I'll get by for now as this 3D exercise was just for a dog and pony show. Time to update again.

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ROBP
ROBP: Thanks but it appears you're using MEP 2018, vs mine which is AutoCAD 2014 Professional. I'll get by for now as this 3D exercise was just for a dog and pony show. Time to update again.

 

Yes just getting the hang of Mep for now but i had 2014 full 4 years ago and i recall that the sweep did work at the time.

Hopefully you where able to open it i can do a save to earlier version if needed just let me know i will repost.

 

Btw the handrail at the right far side need to follow the landing and will need to be reworked and be raised to match the height to follow like the first landing one on the left.

 

Best

 

Robert

 

Awaiting your correction and will sweep again no problem

Sweep 2010 version.dwg

Edited by ROBP

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ROBP
ROBP: Thanks but it appears you're using MEP 2018, vs mine which is AutoCAD 2014 Professional. I'll get by for now as this 3D exercise was just for a dog and pony show. Time to update again.

 

TrueView was always helpfull when newer version needed to be converted prior update on my side.

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Dadgad
Yes just getting the hang of Mep for now but i had 2014 full 4 years ago and i recall that the sweep did work at the time.

Hopefully you where able to open it i can do a save to earlier version if needed just let me know i will repost.

 

Btw the handrail at the right far side need to follow the landing and will need to be reworked and be raised to match the height to follow like the first landing one on the left.

 

Best

 

Robert

 

Awaiting your correction and will sweep again no problem

 

The fact that you were able to sweep this intrigued me, so I revisited it, with Autocad 2013.

I saw no reason why a vertical could handle this, but Vanilla could not.

I noticed that Bill's region (which struck me as an odd choice) for the handrail profile was not symmetrical, so I redrew it with a closed Polyline.

I found that unless I clicked on the Alignment option and DECLINED it, that it would rotate the profile during the sweep.

 

I also used PE (polyline edit) on the spline, which converted the spline path to a 3D Polyline.

Then it swept fine.

This is not to imply, that I disagree with your earlier assessment regarding the path, as I do agree with you. :beer:

remember to decline sweep object alignment option.JPG

SweepMeNot works.dwg

Edited by Dadgad

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SEANT

As a bit of an ‘aside’:

 

You’ll notice that every sweep posted to this thread has a mild twist to one end or another. As mentioned previously, only sweeping a circle will hide this twist.

 

I think changes of direction within a sweep need to be restricted to one orthographic plane at a time. If that’s true, both sides of the landing area need modification. A slight transition zone, as can be seen for any curve type in my attachment, allows sweeping along the span without twisting.

Versions.dwg

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Dadgad

Very interesting Sean, right you are, I hadn't checked, nor noticed that slight rotation.

I did check, and swept all three of your paths, and they worked properly, without incident! :beer:

 

I won't pretend to understand it, but I can certainly confirm what I see. :|

 

Might this problem be addressed with the TWIST mid command options, BANK or EXPRESSION?

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SEANT

I don't think there is anything that can be done while using 3DPolys. Based on what AutoCAD has to do at a junction/miter, use the same incoming section for the outgoing section, a change of direction accompanied by a elevation change will always produce a twist.

 

I'm not so certain about splines. Does the mid command twist allow some sub-division of the path? I don't have time to check now but my initial assumption would be that it doesn't. The Loft command, with guides that force the profile along paths that stay aligned, would work. But that creates more work for the set-up. In light of that my two transitional zones aren't so bad.

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JD Mather
R.... vs mine which is AutoCAD 2014 Professional...

 

What is this "AutoCAD Professional"? I've never heard of it.

Can you post a screen capture?

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