drawing airfoil from coordinates

[Anonymous]

I am trying to draw an airfoil from coordinates generated from another program.   Looks like I need to "import spline csv"    I cannot seem to get a format from excel into somethint that fusion 360 likes. 

[James.Youmatz]

Hi @Anonymous,

I think I can help you out here. I have seen people grab the airfoil data from a .DAT file before so I included those steps. If these don't apply just skip those.

1. Open the .DAT file in Excel.
2. Go through the .DAT import wizard. On the first screen, make sure to choose the appropriate option under "Original Data Type". For the test DAT file I used, I did not have my values as comma separated, so I needed to use "Fixed Width" in order to make sure that my values for X fell into column 1 and my values for Y fell into column 2. If you click Next, it will give you a breakdown of the columns, just verify here that it works. Also, only include numeric values, no words or anythings.
3. If all is okay, press Finish.
4. If there is only X,Y data, make sure to add a Z column as well. If there is no Z data, just add all zeros. 
5. Double-check the Excel sheet and verify that there are no row breaks or invalid characters as this will mess it up in Fusion 360
6. Save the File from Excel as a .csv (comma delimited).
7. For verification, open the .csv in Notepad to see if it is properly separated.
8. In Fusion 360, in the File menu select Scripts and Add-Ins. Scroll down to Import Spline CSV and double click the one with the yellow and blue icon. Then open the .csv you created and the airfoil should be created from the data points.

Realistically all a CSV file is a text file with each row of the file indicating a point, and each value, separated by a comma indicates a coordinate (X,Y,Z) respectively. Using a text editor program such as Notepad++ is really good as it breaks it down by line. A sample would look like the following.

.25,1,0

.5,1.5,0

.75,1.75,0

Let me know if that worked or not!

Thanks,

[vex]

That's a helpful trick to know about the import on csv.

As a segue I would recommend using a spline with 5 cv to do the profile (unless you're doing a supersonic airfoil shape... which begs the question). There was a recent paper on this process (AIAA I think... but I've had trouble finding it as of late) which utilized that process as a means to create a very large number of airfoils for analysis (VLM) and compared those results to known airfoil shapes for which they matched. They found they were able to secure the airfoil shape, with less required information (rather than 100+ data points they used maybe 12 variables at the most to describe the airfoil), and higher fidelity. They also so improvement to the profiles by matching the pressure distribution from the analysis to similar analysis to known shapes (NACA 4-, 5-, and 6-series for instance).

I say this because; regardless of how accurate the data points, I have found that the eventual spline that is run between the points will not run true/fair. Even eventually scalloping in some of the more heinous offenders. As a consequence the graphical representation, parametric integration of components, and the resultant discrepancy between that geometry and analysis performed will vary, sometimes significantly.

[vex]

Seems my ability to edit this post has passed, so I place this link here to link a similar thread which may help explain the process:
https://forums.autodesk.com/t5/design-validate-document/aerodynamic-fillet/td-p/6031663/page/2

[Anonymous]

Thank you I had some numbers that I had used in a previous project in an excel file.  Added a column  of 0's for the z value and exported it as a CSV file.  For some reason when imported into A360 the numbers did not scale properly.   The coordinates were for a 1" chord and it was only about .4   As this was for a little model airplane I am not concerned about being exact so I manipulated the numbers in excel and got the chord I wanted.  I then put some numbers in excel to draw a simple spline and the spline after being imported as a CSV file had about the same scaling difference as my airfoil coordinates. Next time I have to do this I will follow your instructions exactly and see If I get different results.

[dghylin]

Great tip James...I import into DraftSight using a script file, will have to try this in Fusion..

Don

[dghylin]

Had a few minutes here so decided to try James method to sketch an airfoil using .dat files. Here's how I did it.....

Copied the .dat file into Excel. I had to run a "text to columns" operation to get the x and y coordinates into two columns. There was no z coordinate so added "0" in the cells in the next column. Make sure this data ends up in Col A, B, & C.

As Fusion reads scripting in centimeters, regardless of the setting you have, I had to manipulate the data in Excel prior to saving to have the result in Fusion in inches. Also wanted to provide for the chord desired.

In Excel....moved over a couple of columns(E) and entered the chord that was desired in E1. Then in F1 wrote this formula...

=A1*2.54*$E$1

Drug that formula across to H1. Drug F1 thru H1 down to the bottom of the list.

Copied Col's F1 thru H1 and pasted into Col's J thru L as value.

Delete all Col's up to but not including Col J. Save file off as .cvs as described above.

The result, read into Fusion as a sketch, will be in inches and have the correct chord.

Works great and takes longer to type it out than it does to do it....:)

Thanks again James for the tip....

Don

[Anonymous]

While the method in post 2 works, it is rather awkward. Is there any plans to provide direct import of .dat files as some of the packages do? Most do not require a z coordinate, since they assume it is a sketch entity on the construction plane it is being imported onto. They also ignore the name at the top of .dat files, and ask for a scaling factor in the import dialogue. Even a .txt import with those features would be OK.

Thanks.

[Anonymous]

This app imports Dr. Selig's .dat files perfectly:

https://apps.autodesk.com/FUSION/en/Detail/Index?id=3044478757760121899&appLang=en&os=Win64

[TrippyLighting]

---

@vex wrote:
That's a helpful trick to know about the import on csv.

As a segue I would recommend using a spline with 5 cv to do the profile (unless you're doing a supersonic airfoil shape... which begs the question). There was a recent paper on this process (AIAA I think... but I've had trouble finding it as of late) which utilized that process as a means to create a very large number of airfoils for analysis (VLM) and compared those results to known airfoil shapes for which they matched. They found they were able to secure the airfoil shape, with less required information (rather than 100+ data points they used maybe 12 variables at the most to describe the airfoil), and higher fidelity. They also so improvement to the profiles by matching the pressure distribution from the analysis to similar analysis to known shapes (NACA 4-, 5-, and 6-series for instance).

I say this because; regardless of how accurate the data points, I have found that the eventual spline that is run between the points will not run true/fair. Even eventually scalloping in some of the more heinous offenders. As a consequence the graphical representation, parametric integration of components, and the resultant discrepancy between that geometry and analysis performed will vary, sometimes significantly.

---

I've been wonder in about the same thing. Fidelity.

In essence I was working on a project with an NACA Airfoil curve and imported the data into CAD (not Fusion 360 in this case). The curvature of a curve through these points was absolutely terrible.

However, a nice 5'th degree CV curve approximated that profile very nicely with excellent curvature.

As such the question arose whether a profile with excellent curvature would not actually provide better characteristics than a monster with 100 "precise" points but crappy curvature.

[Anonymous]

I just looked closer at my airfoil imported. The leading edge is true to the pattern I made 20 years ago on Profoil but the trailing edge has a little issue on the upper side between points 3 and four from the trailing edge.

[valR7UZK]

It worked as advertised awhile ago creating very smooth wing profiles as splines in a sketch. But recently I tried to import again one of the .CSV files into Fusion but nothing appeared in the active sketch like the operation was disabled.

Anny suggestions to try?

[valR7UZK]

"in the File menu select Scripts and Add-Ins. Scroll down to Import Spline CSV"

I used this method before but now I can't find scripts or add ins in the latest Fusion 360

What else would allow me to import a CSV file?

[James.Youmatz]

Hi @valR7UZK ,

This is now found under the Tools tab.

[valR7UZK]

I ran the CSV script in a XY sketch but nothing showed up.

Attached is a sample of the CSV file

[valR7UZK]

OK so the spline script is now under tools which is fine but something else has changed. I tried importing a .csv file that generated a spline in the past. Now the same file generates nothing!

[davebYYPCU]

You are not trying to use the actual .jpg file?

but do have a .csv file that has those numbers listed, they are a valid list and format

I checked and found the script is still there, if things are still unclear, and it worked for me, here....

Select the script, press Run, select the file, and I got the spline in the front view, without a plane selected...

Might help....

[valR7UZK]

I created a csv file with 0 in column A, Y and Z coordinates in cols. B and C.

I created a sketch in the YZ plane and followed the procedure outlined here. No import showed up.

The Y range is 12" to 1.5" and Z range is 0" to 80". 

Where is the spline?

[valR7UZK]

I have a start up license. Is it possible this functionality is not enabled?

[davebYYPCU]

I don’t think it is a Licence restriction.

Does Fusion Create a new sketch?

Is the sketch folder Eyeball turned on, 

Timeline on or off, which design mode when starting, lots of things to check, 

Csv is plain vanilla, no labels in the columns, first line is a valid point position?

(Same as the jpg, your stated range is not that jpg values, no formatting like ‘’ in the list?)

Can you attach the Fusion file and CSV files, could be X / A column all Zero, that is having an effect, but I have done 3d Splines so should work.

Might help