![]() |
My FAB
At 526 Hours:
Note that black lines are also cracks ![]() Solution: Doubler plate and brace No more problems since. Now at 1380 hours ![]() |
FAB slippage
Quote:
If your FAB is slipping on the fuel servo air inlet, I would look to the tightening sequence for the installation hardware. The donut should be installed and tightened onto the servo prior to the 4 bolts that hold the mounting plate to the donut. Once the donut is installed, these 4 bolts may be tightened. I will look for a couple of photos of my modified FAB. Basically, I bought several diameters of SCAT tubing and selected the size that best fit over the end of the FAB. I pulled a turn or two of the wire reinforcement from between the plies of the tubing to allow the tube to conform to the profile of the FAB opening. I then used RTV and large head pulled rivets to attach the SCAT tube to the FAB. I then trimmed the length of the tube until I had what I deemed a reasonable preload on the cowl inlet flange. I shaped the opening of the SCAT tube (by bending the wire) to fit the opening in the cowl. Sombody with more time or skill could construct a fiberglass transition piece to scarf onto the FAB to provide a circular opening that would easily accept the SCAT tube. Imagine an all fiberglass FAB... Good luck, Dean |
Huh. Not quite sure how the tightening sequence would affect this, but I am not discounting what you are saying either - things have a way of looking a little different when you actually have the objects in front of you. I'll try your suggestion when I get back to the airport and think it over more at that time - certainly couldnt hurt, eh? Thanks for the description of the scat transitions and I look forward to any photos you may have.
regards erich |
Quote:
|
I keep thinking that this would be a good part for someone to offer an improved version of. I have certainly replaced several of them.
For a couple of reasons, I cut back the seal material on the air box so that it doesn't touch the cowl anymore. I thought that would help but noticed yesterday that the plate is cracked once again. |
Problem: cracks
Solution: steel No more cracks |
Quote:
Wow, I am mystified by Larry's plate cracking even with no contact with the cowl. The FAB isnt very heavy and would seem to be adequatly supported. I was sure that the cracking folks are experienceing had to be due to differential movment between the engine and the cowl. erich |
Except that...
Quote:
|
Use thicker aluminum
I made a new plate out of thicker aluminum, about twice as thick as stock. I also moved the FAB over about an inch and ended up having to notch half of the top seal in the filter, not a big deal, the filter can only go in one way now and you have to get it aligned right. This was a pain in the #### but not really tough and I ended up with a solution that won't rub on the cowl (probably why many of them crack anyway).
Randy 8A Finishing, FWF |
Double plate (mostly)
Part of the casting on the rear of my carb extended below the mounting surface. In order to address this problem and strengthen the mounting plate, I put a large doubler on the mounting plate.
Basically, I have 2 mounting plates riveted and prosealed together. I cut the top plate even with the rear of the carb mounting surface (I think I used .063). The full size bottom plate then clears the casting on the carb. This way all 4 carb mounting bolts are through double thick material and most bolts for the FAB are also through the doubler. |
| All times are GMT -6. The time now is 12:26 AM. |