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Pyramid coil?

Good Morning from a frosty Wales

I am attempting, but not succeeding, in the drawing of a pyramid. However, is is not an Egyption style solid pyramid, but a rectangular coil pyramid. The 'why' may help to explain. We have solar PV on our roof and have recently had the unused chimney capped off. This has proved attractive to the local Herring Gulls looking for nesting sites. Herring Gull droppings are bad news on PV panels as they cover so much surface. My plan is to develop a rectangular wire coil that will attach to the four sides of the chimney and rise to a point. If a Gull can build a nest on that shape then I will applaud it, but the hope is that it will defeat them. Why do I want a coil? I thought that artistically there would be congruence with the lazy coil of wood smoke on a winter's day. Additionally a coil would offer less resistence to high winds which are not unknown in this part of the world.

The specific Alibre Atom problem is drawing the coil in 2D sketch mode as a continuing rise of (say) 10 degrees seems to defeat me. I suspect it is down to my incomplete understanding of planes. Once the basic line is drawn then I presume it will simply require a Sweep.

If there is a tutorial on this already, please point me at it. I have done some searching, but have not succeeded with that either.

Best wishes

Pete
 

bolsover

Senior Member
I'm not sure how @idslk constructed his pyramid but the attached might help..

1 Make a rectangular sketch (Sketch1) on the XY plane.
2 Create a new plane at some offset from the XY plane.
3 Make a second sketch on the new plane (Sketch2)
4 Make a Loft from Sketch1 to Sketch2
5 Fillet edges of loft as required.
6 Create a 2D rectangle sketch on the YZ plane (Sketch 3)
7 Create Helical Boss of Sketch3 with height and pitch as required for your pyramid

At this stage you should have something like this:
Screenshot 2023-03-03 162721.png

8 Create a 3D sketch. Select 'Project to Sketch' and select the face highlighted purple in the image above.
This should give you a 3D sketch like this:
Screenshot 2023-03-03 163311.png
9 Edit the sketch to remove the outer spiral and lines connecting to inner spiral so that you are left with this:
Screenshot 2023-03-03 163618.png
10 Create a 2D sketch (Sketch4) on the YZ plane - something like this:
Screenshot 2023-03-03 163850.png

11 Create a sweep of Sketch4 using the 3D sketch as the path.
12 Suppress all features except for the Sweep. and you should have this:
Screenshot 2023-03-03 164308.png

David
 

Attachments

  • PyramidCoil.AD_PRT
    1.8 MB · Views: 3
Hi Stefan

Many thanks for the post. Yes that is exactly what I had in mind.

The device will have rods at each of the corners that go up to the top and meet in in the middle to give a 'point'. Below the pyramid they will go straight down and probably be welded to some strip that will be used to secure the device to the brickwork at the top of the chimney. Given the size of the chimney, those four rods will probably need several others adding on each side to make a sturdy structure. As you can see from the picture, the device needs to clear the chimney pots as the two on the west side are 'next door' and not blocked off.

The construction process should be straight forward once the drawing is correct. A hand small pipe bender will easily bend 6mm steel rod so it might be slow but it will work. The corner stays and the securing strip will all need to be welded. That is why I was actually plannning to pass the task, once the drawing is correct, to Spike the Blacksmith. [Spike the Blacksmith] She is a very competent metal worker and artist. I am also thinking that it would be fun to top the device with y Ddraig Gogh (Red Welsh Dragon) as a wind vane.

So all I need now is to learn how to draw what you drew.

Regards

Pete
 

Attachments

  • IMG_20230205_Chimney.jpg
    IMG_20230205_Chimney.jpg
    173.2 KB · Views: 8
Hi David

Thank you for the detailed instructions. That sounds to be a very sensible way to create the structure but not a way I would have thought of at all. I shall neak away and give it a whirl after dinner this evening!

Best wishes

Pete
 

bolsover

Senior Member
Hi David

Thank you for the detailed instructions. That sounds to be a very sensible way to create the structure but not a way I would have thought of at all. I shall neak away and give it a whirl after dinner this evening!

Best wishes

Pete
No problem - The original idea for this technique was not mine but works very well when you need a 3D spiral on some otherwise difficult surface.
David
 

DavidJ

Administrator
Staff member
Atom3D does not support 3D sketch, which is quite a handicap in performing this particular task...
 
Hi Everybody

Many thanks for your comments and suggestions. I have followed David's suggestions and developed a rather nice Egyption Style pyramid.

Pyramid (600 x 382).jpg

The helical coil went quite well after I got rid of the self referential issue and it then 'looked the business'.

Helical Coil (352 x 248).jpg

I felt that I was clearly onto a winning run by then so the next task was Project to Sketch. Sadly, in Atom that should probably be re-labelled Project to Pancake.

Project to Sketch (633 x 398).jpg

Undaunted, I decided to download David's file and see what he had done. Reverse engineeering is always useful. Atom, however, had other ideas. It reported that David's file was from a later version of Alibre and my elderly version 24.0.1.24044 could not cope. Moving on to Stefan's kind offering it was unfortunately the same problem - software too old!

It looks as if I will have to make do with 2D unless somebody has a fix in their portfolio. However, working on this has helped to clarify ideas.

y Ddraig Goch (549 x 600).jpg

Thanks to everybody.

Best wishes

Pete
 
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