Hey guys, I just finished CAD-ing up some fins very similar to the FCS B-5 bonzer set that seems to be discontinued.
The design can be found here.
If you dont have a printer an wanna give them a try, you should be able to use an on-demand printing service at an affordable price.
The spec (in mm) are:
Front: Base: 120. Depth: 53.
Rear: Base: 137. Depth: 70.
with 18 degrees additonal cant
Hello and thanks for the files Apple_Pie!
I am trying a set of the fronts on the printer now, info from Cura shown below.
Would you have a minute to explain your process in FreeCAD please ?
If you are not aware, one of our members ‘Hans’ is the author of finFoil.
Hey J
Im glad you are interested in them. You cues setup looks good, only thing I have done differently is to use a really fine layer height (0.12) for hydrodynamics. I also print them at 210 for strength but I think that maybe be just superstitious.
I was inspired by the finfoil project, which I would have used if I wasn’t broke.
I used the curved shapes workbench in freecad , which streamlines the process a lot. It just needs you to provide a chord profile, cutout and thickness profile to build the foil. I put some of the sketch variable in a spreadsheet in an attempt to get it to work more like finfoil, where you can change depth/chord and have it generate the foil correctly, but at the moment it just breaks a bit. My “template” file is on my thingiverse account, and if I get it working how I want it too I will probably make a post.
The first set is off the printer. They look nice. Mine ended up at about .262" thick at the tabs whene they would nomally be .250" or a hair below, the commercial ones I have are .238". The CAD file was fine so I attribute this to my printer ( pretty amazing that it is that close after so many layers printing) and nothing that cannot be fixed. I probably should have printed them at a finer setting to reduce the ‘stairstep’ effect.
PS Saw you just posted, thanks!
Hi; the side runners are just that and in many cases do not need the covex foiled outer side; I mean; again, in many boards, work better with a flatter (flatter than those foils) outer side.
That’s good to know. The one thing I couldn’t get data on from the fcs b5 fins was the thickness. However I tried to get it close by comparing to the fin plug width. Another issue I need to fix is I believe the trailing edge gets far too thin and flimsy. Also the fin plug recesses are on the wrong side i think. I won’t be able to fix this stuff until after Christmas.
Wrieup and pictures of the FCS fins, showing/describing the flat inner face:
https://www.cleanlinesurf.com/fcs-b5-bonzer-quad-fin-set.html
I want to say that most tabbed side boxes before FCS2 have the grub scews on the inside. Center boxess and FCS2 have one screw each side. Having the relief on both sides would be ideal.
I would consider adding .031" [0.8mm] to the flat face to thicken the foiled edges, and then maybe take .01"[.25mm] off the tab thickness.
I am very impressed by the FreeCAD work, I use it to view stuff all the time but am a rank beginner drawing with it.
I’ve just finished a little update for these. Edges are thickend up a little, relief added on the correct side and tab thinned out. Thanks for the feedback.
Freecad takes a while to get into but I think it has taught me a lot about CAD and made me a better modeller in general.
Apple_Pie,
The new files look great. Printed the fronts and they dropped right into the kid’s old board with the Culprit/Ausfinco type triple-lobe, double-tabbed boxes. Now to fix the stripped-out grub screws…
My Mind Is Blown! Shot full of holes with .00.
