Fantastic Fan opens itself and destroys itself: Easy to Remove and Replace with MaxxAir?

[paddlesurf.net]

Greetings,

I've got a 2017 Hawk. For unknown reasons, my front Fantastic Fan opens itself. Really. I think it may have to do with some type of vibrations generated by my particular camper (flatbed version). I've already destroyed one Fantastic Fan because it vibrated itself open in Wyoming and then broke the plastic tab that the lifting arm attaches to.

I was able to divert myself to the factory on the way home and they were awesome. They immediately replaced the broken vent/fan and then made some custom straps to wrap around the handle of the fan to keep it from vibrating itself open. This just caused the plastic handles to strip out when the inside metal bolt spun against the plastic threads. So no solution there.

It's amazing the will of this thing to open itself - considering it's opening against the direction of the wind blowing on it. Interestingly, the rear Fantastic Fan DOES NOT open itself - it's only the front one!

On my last Baja trip (I've got 20k or so miles on the camper/truck in Baja and this will go up - I'm down there all the time) I had zip ties looped around the lifting arm pulling the vent closed and down. This time the "up force" was so much it, once again, busted the plastic metal tab and the vent cover is flapping around up there again.

I think something else needs to be done rather than just reinstall a new Fantastic Fan. The MaxxAir fan has two lifting arms and also has a built in lock on the twist knob to lock the vent into position. Additionally, if the vent does open itself, MaxxAir has a rainguard cover so I won't really care if the thing is open while I drive.

So I'm going to switch that forward vent with a MaxxAir - thus my question: How difficult is it to remover that old Fantastic Fan and to replace it with the MaxxAir?

Specific questions:

1. How do I access all side of the Fantastic Fan without destroying the one piece aluminum roof - I'm fairly heavy, 230lbs (all muscle).

2. How difficult is to scrap all the adhesive sealant off the roof?

3. Do the new MaxxAir screws just just the Fantastic Fan holes or do I have to drill new holes in the roof?

Thanks ahead of time,

John

 

[Jack]

Hi John,

I installed a MaxxAir on the front opening in our Front Dinette Fleet..We chose the MaxxAir because we could run the fan at a very low speed, even with with the vent closed - to circulate air while sleeping. The downside to the MaxxAir are the PIA controls.

It's not particularly difficult.Some years ago, on our previous Eagle, I replaced the rear Fantastic Fan and I recall that it was not a great effort to remove it. There should be other posts on removing the Fantastic fan. I installed the MaxxAir about 3 years ago, so the following may miss a step or two, but the key points are covered.

Check with FWC on roof weight limits. You might be be to lay down a piece of plywood to distribute your weight.

The fan is sealed with butyl tape (inch wide, 1/8 thick non hardening caulk)`. After removing the screws on the Fantastic fan, gently pry up the square frame. Then scrape off the remaining butyl tape with a plastic putty knife.

You will need to drill new holes for the MaxxAir. I found that the Fantasic Fax inside square frame worked better than the one that came with the MaxxAir. Lay the outside MaxxAir frame down and center it with respect to the inside frame. (The fan itself is a separate unit and is mounted inside the outside frame later..Drill new holes as needed. Then caulk the just the holes with Silastic Sealant (what FWC uses) or 3M 5200 marine caulk. These caulks do not fully harden. Stick the butyl tape to the outside frame edge or onto the roof, and then set the frame onto the roof and screw it down. The fan unit then fits into the outside fame and is held in place with four screws.

 

[paddlesurf.net]

Thanks for the info Jack! I'm most concerned with harming the roof by having to put weight on it. Seems like a relatively easy job... working up the nerve to tackle it.

 

[Vic Harder]

John, the front one must be getting a "back draft" from the turbulence over the camper. And not just a little bit!

I recently bought a fantastic fan and installed it into an existing vent. The vent was only sealed with silcone, and the roof screws came out easily.

I sealed mine with Butyl tape (homedepot). Not sure I would use 3m 5200... That's a seriously strong adhesive, not just a sealant. If you must use an adhesive, 3m 4200 isn't as strong.

 

[paddlesurf.net]

John, the front one must be getting a "back draft" from the turbulence over the camper. And not just a little bit!

I recently bought a fantastic fan and installed it into an existing vent. The vent was only sealed with silcone, and the roof screws came out easily.

I sealed mine with Butyl tape (homedepot). Not sure I would use 3m 5200... That's a seriously strong adhesive, not just a sealant. If you must use an adhesive, 3m 4200 isn't as strong.

Never thought about that - some type of backdraft vortex - lifting at the lid? It's really weird. At first I thought it was me forgetting to close it but then after a few times where I specifically closed it with the intent of checking to see if it opens itself, I did find it opening. Did you put weight on the roof to those screws out - if so, did you do the plywood thing to spread out your weight?

 

[oldhotrod]

I had the same lifting problem on a Granby with single rear vent. The air is very turbulent and rolls across the flat roof. I found that there is too much gap between the two gears operating the cover on the low quality lift arms. As air buffets the cover, it alternates between pushing down and lifting up, slowly moving the gears until the top is open then it really bangs the cover around till it self destructs. I fashioned a simple spring to hold a little tension on the knob in the closed position when travelling to keep the gears from moving...so far, has worked at speeds up to 90mph...it's kinda crude but...working, I may tune on it later...or try to find some vintage lifting arms and covers

 

[oldhotrod]

A couple of pics...

 

[Ripperj]

I had the same problem in my Alaskan camper with my Fantastic fans. I did like above except with a tiny bungee cord, never had a problem again

 

[oldhotrod]

I had the same problem in my Alaskan camper with my Fantastic fans. I did like above except with a tiny bungee cord, never had a problem again

I used the spring because i wanted the "fix" to be self contained...it is a little ugly so now that the idea is proven, i may tune it up a bit...or not...lol

 

[paddlesurf.net]

I had the same problem in my Alaskan camper with my Fantastic fans. I did like above except with a tiny bungee cord, never had a problem again

FWC factory made some little bungees for me the first time - all that did was cause the handle to strip out against the still rotating "shaft" inside. So instead of stripping out more of those plastic handles, I took mine off completely and ziptied the lid to the fan blades - evidently I didn't zip tie it tight enough because it was able to force itself up enough to break the plastic tab on the inside of the cover! I'm going to a maxxair - the one arm lift design isn't so great in my opinion.

 

[oldhotrod]

It was fine for decades...in my opinion, it is the crappy quality of the current crank arm mechanism and cover that are the issue...but at least the maxx aire will eliminate the issue

 

[Dirtroadsavant]

Our 2017 Hawk Flatbed has the exact same issue. In the most recent cap replacement, I tried the domed version at etrailer. I am no expert in aerodynamics, but since shifting to the dome, we’ve not had a self-open in roughly 8,000 miles of travel. We’ll shift to maxxair in the near future, but this seems to be working in the meantime. The domed version is not a precise fit due to a slightly different layout in the control arm, but it seems to work just fine.

 

[Jon R]

The Maxxaire fan is about 2 inches taller than the fantastic fan, fyi in case your garage door clearance is tight.

 

[Durango1]

Same exact problem for me with my 2018 Grandby flatbed. And here I thought it was just me!

 

[Wallowa]

Can someone post photos that show exactly what is loosening/rotating/extending through vibration and causing the fan lid to open?

Can't visualize it and have never had this problem....does this occur on frame ['flatbed'] and truck bed mounted FWCs?

To open our FF you rotate the black knob shown in a previous post, it takes some force to raise the lid during rotation...I guess it could vibrate and rotate but hard to envision for me...

Thanks...

 

[kmcintyre]

I'm not a fan of fantastic fans (although don't/didn't have this issue) and since Dometic purchased them, customer service has been terrible. This design issue must be known to them....

 

[Wallowa]

I'm not a fan of fantastic fans (although don't/didn't have this issue) and since Dometic purchased them, customer service has been terrible. This design issue must be known to them....

Ok...it may or may not be a design issue; still not clear the exact nature of why and when the lids open on their own...like you said, no problems here with my FF...tis' a mystery...

 

[Jon R]

I have a Maxxaire fan in the rear position of my 2021 Grandby and a vent in the front that I believe is a fantastic fan product. The vent has a single lift arm with a twist knob and gear that don’t work very smoothly. Does anyone know if these non-fan vents have the same issue. In addition to eventually breaking the mechanism, if it lifted and I didn’t notice it I’d wipe it off backing into my barn. Should I be checking it every time before I back into my barn?

 

[ntsqd]

I'll have to look at the brand in our camper (I *think that they are FF's but can't swear to it), but they have a secondary rotary latch for the vent caps.The lift arm isn't strong enough to over-come the latch when latched as I've found out several times. I've yet to break anything, but I have felt the lifting mech straining and had to figure out why. Usually a "DOH!" moment......

 

[kmacafee]

I replaced two Max Fans on the front of my Bundutec Odyssey before it dawned on me that wind coming up over the front nose of the camper was forcibly lifting the fan lid, destroying the plastic lift mechanism. Since I can't move the fan opening, I needed something to block the wind.

I found a heavy duty cutting board at a kitchen store and cut it into thirds. Bolted to some aluminum L channel, I attached it to the roof using 3M VHB tape. In many highway miles and at least one gale strength storm, they have never moved and the fan has had no issues whatsoever.