September 16, 2016
These Caframo fans are TERRIBLE! What a waste of money. We’ve used Hella fans in the past and I’ve been disappointed with what I think is declining quality. We decided to try something else. We blew it (pun intended!).
As you can see by the second, clip-on fan in the picture above, something’s not right. After about a year and a half of use, both of our Caframo fans have now quit. When the first one went out, I figured it was a fluke. I took out the electronics and put in a resistor and a manual on-off switch. While I was doing the work, I started to suspect that the motor was the cause of the failed electronics, with all the debris that fell out of the motor housing. It’s working marginally now with my modifications but making too much noise. I didn’t bother trying to modify the second fan, We just replaced it with a clip-on fan we had in a locker.
Even when these fans were working, they were terrible! They’d vibrate and rattle all the time. We could really only use them on their low setting because of the noise. I tried to take the big, stupid rail off the front of the fan blades (to reduce the spinning and unbalanced mass) and that helped somewhat. I even bought new blades hoping that they’d be less warped than the originals. No such luck.
Also, I’ve never seen any fan attract dirt the way these fans do. I think instead of using mold release during manufacture, they used glue. No matter how we try to clean the parts, they remain slightly sticky and that’s perfect for any stray dust looking for a home. A few days after cleaning the fans, which isn’t easy, they’re dirty again. Check out the picture and you’ll see. That one was cleaned not long before the picture was taken.
I should have known at the very beginning that there was trouble ahead. We bought them in Oz. One was defective out of the box. Also, during their short life, one of the clips that hold the metal front guard on has broken and one of the plastic hubs that hold the fan blades on cracked.
What’s Next?
Since we’ve tried two of the expensive varieties with disappointing results, it’s time for something different. Computer fans have come a long way. Their development is driven by a huge demand for quiet, energy efficient fans. Corsair is now making fans with magnetic levitation bearings. These should last a long time and be very quiet. Here’s a link. There’s also a bearing called “fluid dynamic.” Here’s a good article about those. We’re going to look for 140mm Corsair fans in Oz, and mount them in the Caframo frames. (By the way, even those fans with new-fangled bearings are incredibly inexpensive, at least compared with boat gear pricing.) That should be the last time we need to think about fans for four or five years, I hope. -Rich
Update:
I gutted the Caframo fan and put a 120 mm computer fan inside the frame. It’s really quiet but just not enough air. Next, I put in a 140 mm fan. Now it’s great!
The fan I used is a Corsair ML140 Pro and it has magnetic levitation bearings. It’s quiet and on high speed and moves a good amount of air. On lower speeds, it’s almost silent, while still moving a useful amount of air.
The Technical Details:
Here’s a link to the speed control circuit I used. And here’s a link to the four wire fan pinout. If you build the speed control circuit, note that there’s a missing resistor in the diagram. To prevent over-voltage of the computer fan’s TTL level speed control input, I added a 510 ohm resistor from the bottom of R1 to ground (making a voltage divider). Also, I used a 10 ohm, 1 watt resistor in series with the power input to reduce the supply voltage, protecting the fan from over-voltage when the boat batteries are charging.
It’s a real challenge routing an extra wire through the Caframo housing. In all, this project is far too expensive in time to be worth doing, but what else am I going to do? Scrimshaw? -Rich
