Designing a Surfboard Fin

[quick61]

..and the file.

...and it will now loft properly.

You seem to be coming along nicely.

Mark

[woodbuddha]

fintest1.png (146.39 KiB) Viewed 1493 times

I managed to do a typical raked fin. This was a little harder. I had to loft it in two sections to get the curves right.

TK

[quick61]

fintest1.png

I managed to do a typical raked fin. This was a little harder. I had to loft it in two sections to get the curves right.

TK

Nothing wrong with that. As a final operation, doing a Boolean Union, aka Fuse, will make it one again.

Mark

[woodbuddha]

Hi Guys,

Back again with a new problem. I'm trying to create a negative impression of the spitfire fin in a block. This is for a cradle for a CNC milling machine. I've been trying to do this by creating a solid box, positioning it so that the fin intercepts at half depth along the X-Y plane and then doing a boolean intercept. What I end up with is an empty box rather than a negative impression of the fin in the block. Not sure what I'm doing wrong.

Thanks.

TK

40-80-225-elliptical-fin-cradle.fcstd

(216.58 KiB) Downloaded 55 times

Screenshot1.png (166.19 KiB) Viewed 1428 times

Screenshot2.png (153.47 KiB) Viewed 1428 times

OS: Ubuntu 12.04.4 LTS
Platform: 64-bit
Version: 0.14.3073 (Git)
Branch: master
Hash: 14410215416692475345a857081ba73e1dacce97
Python version: 2.7.3
Qt version: 4.8.1
Coin version: 3.1.3
SoQt version: 1.5.0
OCC version: 6.5.0

[triplus]

and then doing a boolean intercept

You probably talk about Intersect? If i understand you correctly you would want to use Boolean Cut operation for this task!I tested both Intersect and Cut operation and did get nice results. Currently FreeCAD Development Release PPA needs OCE PPA too:

Code: Select all

sudo add-apt-repository ppa:freecad-maintainers/oce-release
sudo apt-get update
sudo apt-get upgrade

This way you will have latest FreeCAD Development Release and latest kernel FreeCAD uses and i guess you will get better results with boolean operation you want to do.

[triplus]

And i had a quick look did you manually compile FreeCAD or added Development Release PPA? On Ubuntu 12.04 currently complete procedure for installing Development Release from PPA would be:

Code: Select all

sudo add-apt-repository ppa:freecad-maintainers/freecad-daily
sudo add-apt-repository ppa:freecad-maintainers/oce-release
sudo apt-get update
sudo apt-get upgrade
sudo apt-get install freecad freecad-doc

[woodbuddha]

Installed the developer realease a month or so ago using PPA.

I'll update and hopefully that should fix the problem.

TK

[triplus]

developer realeas

Development Release not Developer Release. Last thing we need is FreeCAD devs keeping toys for themselves and us "stuck" only on Production Release.

I'll update and hopefully that should fix the problem.

Yes. If it will then i guess "(FreeCAD kernel) OCE devs" did some improvements and maybe somebody with greater insight will give more details.

[woodbuddha]

Upgraded to the latest version and all good.

Screenshot3.png (112.75 KiB) Viewed 1422 times

Thanks.

TK

[quick61]

Edit - Hi woodbuddha, that is looking good.

Here is the release news for OCC 6.7. The things one will probably most notice are -

• Refactored code of b-spline evaluation
• Algorithm of result assembling in Boolean Operations is made parallel
• Considerably improved code stability
• New (more robust) 2D fillet algorithm

Mark