WACKY FUN FIN DRAG TESTS

General Discussion
1

Ok then, for some, the first fin test I conducted went over like a lead balloon.

I felt the pressure to redeem myself once more, like back in the day.

So now I present:

THE WACKIEST FIN DRAG TESTS OF ALL TIME!

First things first…

WARNING: THE PROPOSED INFORMATION IS FOR ENTERTAINMENT USE ONLY

WACKY FIN DRAG TEST #1: Go Waterskiing

Get two identical fins, preferably large center fins. The larger the better.

One of the two fins will get a drag reducing surface treatment of your choosing.

Securely attach the fins to the back of some old wooden water skiis, one fin on each ski.

Buy a ski boat (hey who said R&D was cheap).

Water ski in calm water outside the boat wake.

Blind testing is preferred (you don’t know which side has which fin).

Acceptance Criteria: you can feel a difference in drag under blind testing.

Variables that may affect test sensitivity:

Fin size (more big more drag)

Number of fins (more fins more drag)

Speed (faster speed more drag)

If tests are inconclusive, look at the bright side, at least you went water skiing in your shiny new ski boat.

WACKY FIN DRAG TEST #2: Walk the Plank

Same as Test 1, two fins, one treated.

Replace skis with small wood planks, say 2ft long, 3 in wide, 0.5in thick.

Attached the fins to the planks as if they were small skis.

The two planks are to be identical.

On the other end of the each plank is a small sleeve bearing.

Take the two planks/fins/bearings and insert a long metal rod thru the sleeve bearings so that they are both loosely attached to the rod in parallel. The planks shall rotate freely about bearing, like one sided see-saws. Keep them some distance apart.

Use that ski boat you bought in Test 1 (you should have made your 3rd monthly payment of 60 by now)

Run the test next to the moving boat by placing the system/fins into the calm water off the side.

Observe how much each fin rises out of the water (due to drag) as the fin/planks pivot about the bearings.

Acceptance Criteria: the fin that rises out of the water the least is the winner

Mods: key to this test is equal immersion during testing. To ensure equal immersion, integrate the two pivoting planks into the back half of one skim-like board. The board will ride on top of the water evenly and the two planks will pivot about the bearings.

If tests are inconclusive, look at the bright side, at least you’ve only got 57 more payments on your shiny new ski boat.

I still got the goods baby!

2

And tell your friends they can do secondary testing in the wake waves on the shoreline, kill two birds with the one stone. I like your mind Meecrafty, active and moving forward, but I’d rather spend the boat money on a surfing trip.

3
Quote:

Variables that may affect test sensitivity:

Fin size (more big more drag)

Number of fins (more fins more drag)

Speed (faster speed more drag)

Are these variables or assumptions? Sure you went to UF?? Keep it coming…

4

Oh come on now Rob…still doubtful even with my prestigeous degree from the University of Iraq.

When water skiing on two skis, the fin size is a variable relative to the sensitivity of the test. You are detecting a FORCE caused by drag. A very small fin, say the size of your thumbnail, will result in very little detectable force to the rider. The opposite is true with a very large fin, the rider will likely detect the difference because the resulting force is large enough to detect by human senses. Like when some weed or kelp gets stuck in your fins…lots of drag is detectable. Thus fin size is a variable to the effectiveness, ie sensitivity of the test in question.

Ahhhh yes…the good’le college days in Iraq. I remember those classic days in the Euphrates River. When a 500 lb bomb would hit the river…man those cleanup sets were da bomb! Talk about last minute swell timing…you heard the bombs descent and you had to dash for the board and wetsuit. Sometimes you show up a just little late and the buds would tell you “man ya shouda been here a minute ago”. Those days were a blast!

5

truly sick