FAB Cracking on 10's?

[Carl Froehlich]

Originally Posted by Auburntsts

Way ahead of ya -- I've already started fabricating an interior ring to do just that. Not sure I understand the air filter ablation issue though. I've never noticed any wear on the top or bottom of the filter or the inside of the FAB.

This is a common problem, most noted when the air filter goes conical and starts to bounce around. I added glass to fix this the first time around, then did the aluminum plate as just adding glass back does not fix the root problem. Photo is the fix on the RV-8A. The RV-10 has the same fix but a different, taller filter and modified FAB.

Here is the simple fix.


Carl

[Auburntsts]

Originally Posted by Carl Froehlich

This is a common problem, most noted when the air filter goes conical and starts to bounce around. I added glass to fix this the first time around, then did the aluminum plate as just adding glass back does not fix the root problem. Photo is the fix on the RV-8A. The RV-10 has the same fix but a different, taller filter and modified FAB.

Here is the simple fix.


Carl

Interesting. In 5 years of flying I have not experienced this issue.

[Phil]

I put a .063 plate in my FAB to keep from wearing through the fiberglass. At 200 hrs, I was doing my condition inspection and noticed that the aluminum plate is beginning to show significant signs of wear. I have the filter sandwiches down pretty good to prevent deformation and to ensure a tight seal.

Without the plate, I would already be replacing the box as the filter would easily wear through the glass. I?m sure I?ll be replacing the plate in the next year or two. But installing it was a good decision.

[lr172]

Originally Posted by Phil

I put a .063 plate in my FAB to keep from wearing through the fiberglass. At 200 hrs, I was doing my condition inspection and noticed that the aluminum plate is beginning to show significant signs of wear. I have the filter sandwiches down pretty good to prevent deformation and to ensure a tight seal.

Without the plate, I would already be replacing the box as the filter would easily wear through the glass. I’m sure I’ll be replacing the plate in the next year or two. But installing it was a good decision.

I used packing tape on the bottom of the FAB on the 6. 600 hours and no wear. UHMW tape will also work. The wear is from contsant motion and not pressure. Eliminating friction is the key.

Larry

[Bill Boyd]

With packing tape inside the periphery of the filter, I'd be concerned for the possibility of tape fragments being scrubbed loose and ingested into the engine.

A possible risk?

[TryChick]

Originally Posted by lr172

I used packing tape on the bottom of the FAB on the 6. 600 hours and no wear. UHMW tape will also work. The wear is from contsant motion and not pressure. Eliminating friction is the key.

Larry

Aren't the clips riveted between the nut plates and the aluminum top plate of the FAB supposed to keep the filter from moving around? We just started working on the FAB, and the directions are really bad. All I see are drawings showing the clips, but they give no dimensions for those clips or anything. After checking out a bunch of builds which mentioned the wearing of the bottom of the FAB, we did fabricate a plate to put in the bottom, and were going to rivet it to the bottom using the same rivets that attach the alt air door air inlet, but if the metal plate will also have to be replaced eventually, I'm wondering what would be a better way to secure that bottom plate so it could be easily swapped out?

[Lynnb]

TryChick,

I'd agree the instructions were a bit hard to follow. Heck I almost left the clips out because I missed that part of the instructions. There is some angle that comes in the FAB kit that you cut for the clips, I think if you measure it to get 6 clips they end up being about an inch wide apiece. I just figured out to get 6 even pieces out of it and cut. They you are correct, they mount between the nutplate and top. I added another layer of glass and some kevlar on the bottom of my box, hoping that will be enough to keep any wear down.

Lynn

Originally Posted by TryChick

Aren't the clips riveted between the nut plates and the aluminum top plate of the FAB supposed to keep the filter from moving around? We just started working on the FAB, and the directions are really bad. All I see are drawings showing the clips, but they give no dimensions for those clips or anything. After checking out a bunch of builds which mentioned the wearing of the bottom of the FAB, we did fabricate a plate to put in the bottom, and were going to rivet it to the bottom using the same rivets that attach the alt air door air inlet, but if the metal plate will also have to be replaced eventually, I'm wondering what would be a better way to secure that bottom plate so it could be easily swapped out?