spiral stairs hand rail heavy model

[easyscaff]

Dear colleague,

 

NO, I don't have any problem with making a helical hand rail along the circumference of a spiral stairway (or helical stair stringer)!

 

My only problem is that the method which gives the best visual results (viz. extrude or sweep circle or region along spline) will give a "HEAVY" solid model that HINDERS the performance of AUTOCAD.

Therefore I mostly use the extrusion along a 3D-polyline that gives a a lighter model but less nice visual results (especially when using flatshot for 2D model "representation").

 

Can I set some system parameters that increase the performance when extrude or sweep along a spline ?

 

Standard I use a lot of blocks to increase the 3D perfomance of AUTOCAD, this however is not possible when a visual continuous hand rail is preferred.

 

Thanks !

 

Easycaff

[Dadgad]

Welcome to the forum.

Have you tried doing it as a SURFACE instead of as a SOLID?

I should think that might lighten it up considerably, without sacrificing your display.

I would be very skeptical of using FLATSHOT for as complex a shape as that.

In my experience SOLPROF would yield a much more reliable representation. :wink:

[SLW210]

Do you have an example of what you are trying to sweep/extrude?

 

I have seen great improvments in performance by slightly reducing the size of the profile, i.e. I recentley swept a 2" diameter profile along a complicated path, though file size was relativly small, it really slowed the computer. I then swept the same path using a 1.99999999" profile and performance was greatly improved even though file size was the same.

[easyscaff]

To SWL2010,

 

Please see the attachment showing example of this issue.

 

Best regards,

 

easyscaff

handrails of 3d polyline.dwg

[SLW210]

My computer had no problems with either method.

 

What are your computer specifications and graphics card specifications?

[easyscaff]

Dear SLW210

 

I have used e.g: i7 860 @ 2,8 GHz | 4 GB | nvidia GTX285 | win 7-64.

 

The performance of this computer doesn't give a lot of trouble only with this specific case.

The generation of the solid from circle and path takes some time (approx. 7 sec) and after generation of the solid the view manipulating is hindered.

I have tried with and without hardware acceleration.

Due to the never ending discussion of Direct3D versus OpenGL graphic cards I also will try this today on some OpenGL workstations to see the difference and will let you know the results.

 

Because the file size of the solid is big compared to the rest of the used parts I thought the problem was related to the solid size (also time for generation this).

 

Thanks for your reply

 

easyscaff

[SLW210]

Like I stated previously, I have seen this happen on some of my own sweeps, I redraw the path and slightly reduce the profile size and all is well.

 

Can you post the file after you have swept the profile?

[easyscaff]

Dear SWL210

 

Changing the circle diameter size didn't solve the problem (viz. the entity that is swept along the path, i think this was called the geatrix ? a long time ago)

Also on a steriod workstation with quadro openGL gave same problem.

 

Examples of solid size, way of solid generation is absolutely factor:

 

6800 kB (when joining lines, arc en helix together to spline and sweep or extrude)

192 kB (when extruding along 3D poly)

611 kB (when pervious 3D poly has been converted into spline and extruded or swept)

 

Worst results are when drawing a spline along the helical perimeter and this is used as the path

 

I will let you know when I found some new clues

 

Thanks anyway

 

easyscaff

[dedmin]

Just opened Your .dwg file in Rhino and made the rail - Rhino flies. In AutoCAD it is a pain working with 3D - the simple truth is that this program needs a rewrite, not adding new features! Try the same files with SolidWorks, Rhino, SpaceClaim, Inventor and You will see what i mean!

[3D generator]

It’s been my experience that AutoCAD doesn’t like complex paths when using the SWEEP command. It may work but you’ll end up with the performance issues you mentioned due to a big file size.

 

My advice is to keep the helixes, arcs and lines as separate paths. The downside to this technique is that your returns at corners and transitions are not figured out for you.

 

Fortunately, there is a way around this limitation if you’re willing to take some steps at each return:

 

1. Extend the ends of the solids beyond the ends of the paths at the return so that they completely pass by each other; use SOLIDEDIT with Face option and Offset option* where you can and PRESSPULL elsewhere.

 

2. Use the INTERFERENCE (INF) command to create the solid that forms the return; be sure to deselect the box that deletes this solid upon exiting the command.

 

3. COPY the new return solid twice so you can subtract it from the two solids that pass by each other; this way you’ll still have the return solid to use later when you’re done.

 

4. SUBTRACT the copied return solids from each solid that passes by each other.

 

5. SLICE the excess solids off of the solids that pass by each other using the 3 point method and ERASE the excess solids. Note: SEPARATE will also work if the solids aren’t touching each other after the SUBTRACT command is performed.

 

6. UNION (UNI) the return solid to the two solids that used to pass by each other to create the finished return; use SOLIDEDIT with Face option and Delete option** to delete any artifact faces at the return.

 

* This option will allow the additional length added to follow the curved or tapering geometry of the original solid being edited.

 

** This option will clean up messy face artifacts after Boolean operations; doesn’t always work but worth a try.

 

This sounds like a lot of work but it really goes fast once you get the hang of it.

[easyscaff]

Dear 3D generator,

 

Yes, your workaround is allright, I have not used the slice command before your reply.

Very smart workaround I think.

But it will take some more time when there are a lot of these connections/transitions.

 

Luckily I am not the only one with this sweep malfunction.

 

Thanks,

 

easyscaff

[easyscaff]

Dear dedmin,

 

I have used AC and SW and each program has cons and pros.

So I will not declare AC is better than SW or vice versa.

It just depends on the job, sometimes I prefer AC and for other work I use SW.

It takes some time and experience to determine which program is suitable for a specific job.

 

But I fully agree with persons complaining about the complexity and command redundancy of AC (!).

I have 23 years used AC, also made a lot of LISP programs but found out this can currently be a disadvantage when trying to use the ribbon....

 

Best regards,

 

esyscaff

[ReMark]

Since different users prefer different methods of accessing AutoCAD commands I do not view this "redundancy" you speak of as necessarily a bad thing.

 

What complexity issues are you having? Is it the archaic and sometimes baffling command prompts AutoCAD is famous for? If so, we are somewhat in agreement. That's what happens when programmers instead of actual users design a piece of software.

 

Why would the Ribbon have a negative affect on the use of Lisp in AutoCAD? Can you cite an example?

[dedmin]

Dear dedmin,

 

I have used AC and SW and each program has cons and pros.

So I will not declare AC is better than SW or vice versa.

It just depends on the job, sometimes I prefer AC and for other work I use SW.

It takes some time and experience to determine which program is suitable for a specific job.

 

But I fully agree with persons complaining about the complexity and command redundancy of AC (!).

I have 23 years used AC, also made a lot of LISP programs but found out this can currently be a disadvantage when trying to use the ribbon....

 

Best regards,

 

esyscaff

 

I like a lot of the 3d stuff in AutoCAD - but all this is killed by the poor 3d performance - that is my BIG complain since 2006!! Since then I changed 4 personal computers, 3 jobs with a lot of different software, workstations and etc. and it is always the same - poor, slow 3d performance compared to other software on the same hardware, with the same files!

[ReMark]

I've had only one problem working in 3D and that is when I had the wrong graphics card for the job I was doing. The file was 38MB in size and included a three story process building along with all the skid mounted equipment which had tanks, pumps, valves, instrumentation, fittings, structural framing members and a three level stairway with safety rails included as part of the design. Since that time I've swapped out my computer for a better one (see the Computer Details listed under my avatar to the left). No problems now.

[dedmin]

I took a different approach - invested my money in a new software - Rhino+BricsCAD. Now my "slow" machine is working just fine:D

[ReMark]

Some day I may be forced to do the same.