When setting a fin how close is close enough?

[bojans]

Setting up my son's new ski last night and I got each measurement down to the thousandth. Once I tightened up the block fin length was off by 0.003". Several cycles of this later I called it good with dft off 0.001, depth off 0.002 and length off by 0.002.

How close to actual fin measurements do you try to get to before calling it good? 

[mike_mapple]

TBH thats perfectly fine, so many people will say they can tell a difference, and i know some people that do. Yet I have also been in the boat when my dad "adjusts" the fin...AKA didnt move anything and they say it skied way better. I was also talk to keep it with .004 and it was good to go, he always told me the only real numbers that mattered were the first to (.XX00) Such as a fin needing to be 2.345 in depth if I got 2.341 or 2.349 would be ok. Over the years I have gotten to where I can get them exact. But unless hes is a deep 38/39 skiier being .003 off you should be just fine.

[Horton]

DFT is often the most critical, followed by depth and then Length.

I would say .001 can not be felt and .005 could be a real difference. So the useful margin of error is somewhere in between.

If you are trying to nail someone else numbers or factory numbers the method of measurement is critical. If you measure slightly differently then the person who supplied the settings you will get a different number. 

In the end if is all relative. If you have your numbers and you want to get back to that setting exactly you will feel the delta. If you are trying to hit someone else's settings or the factory settings then you do not even know if they are right for you. In that case close is close enough.

As @mike_mapple  implied the higher level the skier the more critical. 

[jjackkrash]

I don't believe any two people will get the exact same numbers measuring the same ski even with the same set of calipers unless it's an accident, let alone measuring different skis of the same model with a different set of calipers.   So I personally believe you are close enough for a starting point.  

[The_MS]

34 mins into the waterskier podcast with Chet, he has some good info

[teammalibu]

@mike_mapplei watched your dad measure the dft on my ski with it standing tail up 5 times and it read within .001 every time!

[6balls]

@mike_mappleyou dad (the GOAT) adjusted my fin about "a thumbnail" between passes.  That's my kind of adjustment the rest is on me.  I ran to get us pizza for lunch while the others took their sets--Andy was so thankful for some pizza.  Great skier for sure but just a great guy to be around.  Very humble, great humor--obviously incredible talent. 

[Dirt]

I try to get within a few thousandths of each setting except when I moved Hortons fin at Cottonwood several years ago. I tried to move it full aft dft. 

[A_B]

I have read the story behind Jeff Rodgers setting the world record was he made a .001" Depth change right before he skied.  But that is Jeff Rodgers...

 

[Horton]

So this is not close to 2.500?

[Drago]

Not even close to 2.50. It's close to 2.40

[ral]

Get digital, man!

[Horton]

@ral NO! I have digital. Analog is FAR superior.

This error was caused by fin set up too early in the day and not enough coffee.

I still ran 35s and had no idea why the ski felt so odd.

[ColeGiacopuzzi]

@ral+1 for analog! Way more consistent. You'll never go back. 

[B_S]

@ColeGiacopuzzi apparently @Horton would benefit from the ease of reading a digital.😉

[ColeGiacopuzzi]

He just needs new eyes haha

[ral]

@Horton, I love the analog Mitutoyo. A work of art. I also almost only use mechanical watches. Got to love them!

@ColeGiacopuzzi, compare apples to apples. Digital Mitutoyo are more precise, accurate and consistent than analog Mitutoyo, which are probably more consistent than a USD 20 digital caliper. But for sure USD 20 digital calipers are way more consistent than USD 20 analog calipers. 

Analog calipers have advantages in some conditions, like high magnetic fields, or extreme temperatures.

[Horton]

@ral I own Mitutoyo digital as well as a number of sets of economical digital. I abandoned them all and went back to analog for reliability.

especially on hot days I can't tell you how many times I got crazy numbers. changed the batteries, try it again. got crazy numbers and then pulled out analog and everything worked.

[ral]

Leave them in the sun, and they will do crazy stuff. 

[Bruce_Butterfield]

Hmmmm.  @Hortonfor your crazy numbers on hot days, how many beers/scotches were consumed prior to the crazy numbers?

”bad numbers “ with calipers is almost always human error. 

[Horton]

@Bruce_Butterfield @ral No

[ral]

Too early and not enough coffee sounds awfully like aftermath from what @Bruce_Butterfield mentions. 

[Horton]

ok you knuckle draggers can make fun but I had issues with a number of sets of expensive digitals. At my old house my original shop had a roll up door that faced west. I pretty much had to have it up to work and it was often hot as balls. I found that if my hands were sweaty sometimes it made the calipers give CRAZY numbers. It took my a long time to figure it out. Originally I thought it was batteries but I ruled that out. 

The part I never understood was the fact that Mitutoyo claims they are "resistance to dirt, oil, and water".

[Bruce_Butterfield]

Ah at least that makes sense. Water on the moving parts does screw up digital caliper readings. 

[DanE]

When shopping for Mitutoyos make sure you visit their website to check if the store you buy from is a verified retalier.

Lots of clever made China copies out there that may or may not work well in damp condittions.

The coolant proof digimatic reads well even with moist on ski and hands, I use the regular and have not had any issues. Cheap digital is useless if water is involved.

Edited June 10, 2023 by DanE

[Horton]

@DanE pretty sure mine are legit & are the coolant proof digimatic. Although it never occurred to me they could be fake.  my theory is moisture is not bad but sweat is. 

Whatever the analog always works 

 

[Drago]

1 hour ago, Horton said:

Whatever the analog always works 

 

💰

[teammalibu]

All I know is there must be a whole lot of thousandths in an inch!!

 

Edited June 10, 2023 by teammalibu

[teammalibu]

My digital  works great in my air conditioned shop!

Edited June 10, 2023 by teammalibu

[ToddL]

 

 

[Horton]

Andy used a dial. That's good enough for me.