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Jedicut software and foil.dat files from Airfoils database

Posté : ven. janv. 31, 2020 2:53 am
par AndreL
Hi again, I have now finished my cutter and am ready to put it to work. I started to familiarize myself with the software through some examples and youtube videos and have come up with some snags. It's probably my issue but I would like to see how it can be resolved, here it is - i have imported the clarky.dat file from the airfoils database and placed it in the wing cut - wing root. I have noticed that the outline below the x axis is only visible, nothing above (I see half of the airfoil only). If i open the clarky.dat with jedicut profile I notice that the below coordinates are present but the above are not. For some reason the program is not importing the above coordinates. Other Clarky variants are giving me the same result. Does this file or files need to be modified ?
Then i used the same MH44 and MH61 that Keith used in his video and both of those worked perfectly and as he described.
any idea how can I resolve the Clarky foil? or other foils that fail to open properly from the airfoils database? thank you in advance for all your help and any ideas you might have.

Re: Jedicut software and foil.dat files from Airfoils database

Posté : ven. janv. 31, 2020 12:48 pm
par Inelsal
The reason is the wrong .dat file structure

This is the case with files downloaded from the web, probably from https://m-selig.ae.illinois.edu/ads/coord_database.html. Some files on this page are correct, others are not. This can be remedied by opening the file in the notebook and analyzing its structure. If the file has two separate sets of coordinates like this CLARK Y (0.0000000 0.0000000 to 1.000000 0.0005993 and the second 0.0000000 0.0000000 to 1.0000000 -.0005993) it is not useful for Jedicut as the coordinates should start and end in the same place, i.e. 0.0000000 or 1.0000000. You can fix this by copying one set of coordinates to a spreadsheet and using the sort option to change the order of the coordinates. Then paste the inverted coordinates again in the notebook making sure that there are no empty lines in the whole coordinate string. Now save as "All files" with the new name and the .dat extension, eg CLARKY_new.dat. This file should already be read by JEDICUT
I hope you understand because my English is a translator google
Example:

Re: Jedicut software and foil.dat files from Airfoils database

Posté : ven. janv. 31, 2020 4:14 pm
par AndreL
yes that is the location of the database that I picked up the file from, and thank you for your knowledge on the matter. I do see the difference between the two files at the mid point. The lower half of the code is first to last sequence inverted. Would you use excel for such correction or do you or is there something that can simplify this process?

Re: Jedicut software and foil.dat files from Airfoils database

Posté : ven. janv. 31, 2020 10:33 pm
par Inelsal
Maybe there is a faster method of repairing .dat files, but I don't know it because I mainly use .dxf files to work with Jedicut.
It's because I edit drawings in CorelDRW and immediately save as .dxf files which open in Jedicut without any problem.
Even somewhere in the network I found the entire database of profiles in .dxf format and for this reason .dat files are not in use very often.
The only opportunity to use them is the conversion of ready-made files in the GMFC format, which Jedicut does not read.
In the unlicensed version of the program, e.g. GMFCExp, it is possible to save files in .txt format which is equivalent to .dat (often it is enough to change the extension from .txt to .dat, and if not, a bit more work may be required, e.g. with the Profscan program, to get the final result as a .dxf file).

Regards
Józef

Re: Jedicut software and foil.dat files from Airfoils database

Posté : sam. févr. 01, 2020 12:50 am
par AndreL
Again thank you - but I did try the file that you have corrected - unfortunately it causes errors and crashes when you try to install ribs, and if you do a sim cut it seems to cut off half of the leading edge. Then again maybe it was just a rough representation of what needs to be done and for that I thank you.