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Art Smith  
#1 Posted : Saturday, May 12, 2018 2:04:32 PM(UTC)
Art Smith

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what is the expected accuracy of the "Verify Area" tool ??? creating equal area rate stations for my duct project I've noticed what at this point I'll describe as a apparent "difference" between SharkCAD Pro 1370 and Excel (and my calculator). the area of round corner rectangles is straight forward to calculate. accordingly, I've been attempting to use the corner radius as a design variable to achieve precise station flow areas (clearly post smoothing may be required). since we don't have a constant enclosed area lofting option, I've been moving Shark measurements into Excel to calculate the needed station areas required along the center line and the corner radius needed to yield the target area. laborious and error prone for sure, but I want/need linear rate of area change through the duct. the enclosed area along a "Guide Loft Surface"/"Loft Surface" duct/port/runner is lumpy as it's driven by surface geometry constraints.............

round corner rectangular areas (joined lines & arcs) "measured" by SharkCAD Pro don't match the calculated numbers from Excel or my calculator. is there an unrecognized operator error; am I expecting too much accuracy from the "Verify Area" tool; or is there something going on that needs attention?? see attached collage for an example of the basic geometry

Art
artesmith@earthlink.net
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jdi000  
#2 Posted : Saturday, May 12, 2018 2:09:40 PM(UTC)
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Hello Art

Based on the dialog box your cross section profile is or contains splines, and you are calculating based on fitted radius?, the verify tool should be accurate based on the actual geometry.

Can you post the cross section ?

Regards

Jason

Edited by user Saturday, May 12, 2018 3:08:08 PM(UTC)  | Reason: Not specified

Windows 10, Win 7
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murray on 5/12/2018(UTC)
Art Smith  
#3 Posted : Saturday, May 12, 2018 8:55:06 PM(UTC)
Art Smith

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Jason-

thanks for your quick reply! assuming I want to loft the surface, as best I can tell spline representation of something is the only game in town for closed sections assuming it's not circular ............?? the lofting tools ignore/don't acknowledge perimeters created with the round cornered rectangle tools (or I'm doing something wrong or have something set incorrectly). the lofting tools also ignore/don't acknowledge grouped collections of arcs and lines (or I'm again doing something wrong or have something set incorrectly). the perimeters I'm currently using are a collection of arcs and lines joined with the "Join Tool". I had assumed (my bad!!) that since all the joins were normal (G2 continuous if you will), the resulting splines were NOT altering my geometry, only it's representation...................

if the spline representation currently being used is of something other than my collection of lines and arcs, I understand why the areas are different!! is there a means to get access to the points being used by SharkCAD Pro to represent my geometry? clearly adding more points would be an option assuming I'm willing accept the higher compute overhead....... if the current spline representation is not exactly a representation of my collection of lines and arcs, how do I go about lofting a surface with station ribs of my choosing? the lofting tools appear to be doing a fine job of lofting surfaces; I simply need to impose additional constraints to the lofting boundary conditions to concurrently achieve cross section flow objectives and don't mind having to create additional station cross sections to that end.

in a related question, do all of SharkCAD Pro's surface creation tools for complex cross sections (ie: not single lines, arcs, or circles) require the use of splines?

thanks again for your help!!

Art
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cad'n'stuff  
#4 Posted : Sunday, May 13, 2018 10:42:03 AM(UTC)
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Based on your calculations, Sharkcad is only 0.02% off (If I calculated correctly). I don't know how accurate your duct has to be, but I guess that amount is negligible.
MPSchmied  
#5 Posted : Sunday, May 13, 2018 11:50:07 AM(UTC)
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Lines and arcs ahould work better than a spline. Have you used the Repair Curves Tool? I was creating a profile several days ago and i got a edge which the Trim-Tool and the curve repair tool didnt connected right. Just deleting the line and drafting a new one solved the problem. But normally it should work. Also Groups of lines and arcs should work.
Art Smith  
#6 Posted : Sunday, May 13, 2018 12:45:27 PM(UTC)
Art Smith

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Originally Posted by: MPSchmied Go to Quoted Post
Lines and arcs ahould work better than a spline. Have you used the Repair Curves Tool? I was creating a profile several days ago and i got a edge which the Trim-Tool and the curve repair tool didnt connected right. Just deleting the line and drafting a new one solved the problem. But normally it should work. Also Groups of lines and arcs should work.


the simple test file attached illustrates what I'm seeing and clearly my settings could be all or part of the problem. the "Loft Surface" tool ignores/will not acknowledge the presence of either the round corner rectangle or the group of four lines.............

Art
artesmith@earthlink.net

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MPSchmied  
#7 Posted : Sunday, May 13, 2018 1:48:52 PM(UTC)
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Sorry, i do not really know what you wanna do. But i have tested Loft Surface and Skin Solid. Skin Solid works with groups and Loft Surface not. The Image with the destroyed surface show what happens when using Loft Surface with lines and arcs and multiselecting.

Edited by user Sunday, May 13, 2018 1:50:55 PM(UTC)  | Reason: Not specified

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Art Smith on 5/13/2018(UTC)
L. Banasky  
#8 Posted : Sunday, May 13, 2018 1:54:07 PM(UTC)
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I did a 'Lofted Solid' and 'Shell'.0625, don't know if that helps.
Larry
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Art Smith on 5/13/2018(UTC), MPSchmied on 5/15/2018(UTC)
Art Smith  
#9 Posted : Sunday, May 13, 2018 2:53:42 PM(UTC)
Art Smith

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Originally Posted by: L. Banasky Go to Quoted Post
I did a 'Lofted Solid' and 'Shell'.0625, don't know if that helps.
Larry


Larry-

thanks! you have my undivided attention. did you use the "grouped" or "rounded corner rectangle" representation for the non-circular end??

Art
artesmith@earthlink.net
L. Banasky  
#10 Posted : Sunday, May 13, 2018 3:10:04 PM(UTC)
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I used your dimensions. If I draw using the rectangle tool, I change the rectangle to lines, fillet the corners,
and work from that point.
I am not skilled at using surfaces or advanced tools, I 'Extruded the circle
and rectangle .001,then picked the 'Lofted Solid' tool and 'Shell Solid' .0625.
This is new to me, I did sheet metal layout for years, and used triangulation for layout
of Rectangular to Rounds on a full sheet of metal with a center punch and dividers, and
cut it out with an electric hand shear or nibbler, and bent it on the brake.
Progress has come a long way.
Larry
Tim Olson  
#11 Posted : Tuesday, May 15, 2018 11:07:14 AM(UTC)
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>>the area of round corner rectangles

Art, there was a small precision issue for rounded polygons. This is updated in 1371 builds.

Tim
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Art Smith on 5/15/2018(UTC), MPSchmied on 5/15/2018(UTC)
Art Smith  
#12 Posted : Tuesday, May 15, 2018 11:31:52 AM(UTC)
Art Smith

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Originally Posted by: Tim Olson Go to Quoted Post
>>the area of round corner rectangles

Art, there was a small precision issue for rounded polygons. This is updated in 1371 builds.

Tim


Tim-

thanks!!

Art
artesmith@earthlink.net

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