Fan Hole Size dilemma 80mm

[Chunce DeLeone]

I have two 80mm(3inch) fans in a juke that i need to cut a hole for.  I think the full 3 inch hole that these preferably require would make the 4inch box I made to house the juke too flimsy, so what if I put in a 2.5 inch hole instead?  Would that damage the fans in the long run by choking the air and making them work harder, or is it not that big of a deal?  Also I feel that the 80mm fans are plenty for this setup so if the air flow is a little less the juke will survive. 

[Turnarcades]

Shouldn't make a bit of difference. As long as it is able to pull in/push out some fresh air you will be fine. I wouldn't worry about sructural integrity though if you are concerned about that. Most ply or MDF boards over 1/2" thickness are surprisingly tough, especially when all screwed together in a 'box'.

[Chunce DeLeone]

Thanks Turncades!!!!  Now I am leaning towards the 2.5 inch hole, the reason i am worried about structural integrity is that it is close to the corners, so the screwed in part is probably going to take a hit with the hole

[Franco B]

You don't have to use the mounting holes if you are afraid that they will be close to the edge. There are a few ways you could secure them but I would probably make a couple of 40mm or so long clamp blocks out of MDF and then use them to centrally clamp the fan to the inside of the box.

Something like:

Side View



Top View

[Turnarcades]

Yeah... what franco said....