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-   -   Is this New or Refurbished? (http://www.wakeworld.com/forum/showthread.php?t=797938)

h20mobius 05-04-2013 4:45 PM

Is this New or Refurbished?
 
Just received my new, CNC'd OJ prop today, but I was surprised to see two blades were perfectly machined, and two others we "ground and polished." Tried calling OJ, but they are closed until Monday. Has anyone else seen this on a "NEW" prop? I thought the purpose of milling them was to keep within a 1/1000th tolerance? If that's the case, why are they having to grind them post-CNC?

Machined Blade
https://www.dropbox.com/s/r0w9krpz4uniqx1/IMG_8206.jpg

Ground Blade
https://www.dropbox.com/s/lq9k3dnugqlwtyz/IMG_8204.jpg

Can't seem to get the image to embed, so here is a link
http://www.dropbox.com/s/r0w9krpz4uniqx1/IMG_8206.jpg

http://www.dropbox.com/s/lq9k3dnugqlwtyz/IMG_8204.jpg

dezul 05-04-2013 4:49 PM

Oj prop is local to me. I bought a new prop at the beginning of spring. It was mostly cnc'd with some grinding. I am not sure why it matters. As long as it is balanced then it should work as intended. Cosmetics of the blades dont mean much. They will tarnish shortly anyways.

dezul 05-04-2013 4:54 PM

http://img.tapatalk.com/d/13/05/05/setenaqy.jpg

Mine cnc on the front with grind on the back. Not a lot of grind but some.

chpthril 05-04-2013 5:36 PM

Ive seen this a handful of times. Its not uncommon for some grinding to be done in order to balance the props after machining.

CTXxRoss 05-04-2013 5:36 PM

stuff can warp during heavy machining... I have been doing machine work for around 6 years now. I wouldn't worry to much about it man, grinding is not uncommon in a machine shop and they may have done it to get it back into tolerance. 1/1000th is a tight tolerance and one tiny mistake can throw it off.

wakebrdjay 05-04-2013 5:43 PM

I bought a new Acme prop from a shop,it's also ground.I contacted Acme to ask if this was normal for a new prop and they said it was.

boardman74 05-04-2013 6:09 PM

TigeMike hit it on the head. I have also been told it's part of the truing/ balancing process post CNC.

h20mobius 05-04-2013 7:58 PM

Gotcha.. That makes sense. Thanks for the replies.


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