Tight Flap bar

[comfortcat]

In my 9A, I'm installing the flaps and the bar is really tight, even with the center support unbolted.

Best way to fix that? Can I sand the white support blocks?



Dkb

 

[Kyle Boatright]

Did you paint the bar? What I found on my -6 was that the rudder bars and the flap bar were all stiff for a few hours because of paint thickness, but after a few hours, they self-machined and began moving freely.

 

[Rupester]

My flap bar came with the center 2" or so unpainted ... that is, no powder coat at all. It fits and pivots perfectly. I suspect it would be very snug with a coat of powder paint in that area.

 

[Don Jones]

Be sure and check the ends of the bar, mine had some burrs around the entire circumference. It appeared they were cut with a pipe cutter, a few seconds on the scotchbrite wheel and they were not tight anymore.

 

[comfortcat]

Bar is clear and burr free. Also, the ends and center seem to have a slick Silicone like solid black material. I assume it was a factory material to help with movement. I did not want to sand THAT away. Am I missing something?

My flap bar came with the center 2" or so unpainted ... that is, no powder coat at all. It fits and pivots perfectly. I suspect it would be very snug with a coat of powder paint in that area.

 

[airguy]

When you cut the delrin block in half for the bar, you remove a section of that block the same width as your bandsaw blade. Without that section, when you put the two pieces together the hole is now smaller and out-of-round and won't fit well on the flap bar, causing it to bind. If you assemble the cut delrin blocks around the flap bar with washers on the bolts between the delrin blocks, the washers will take up the missing space and prevent them from binding on the bar. This is mentioned somewhere in the drawings or instructions, I remember seeing it once but can't remember where.

 

[Don Jones]

Bar is clear and burr free. Also, the ends and center seem to have a slick Silicone like solid black material. I assume it was a factory material to help with movement. I did not want to sand THAT away. Am I missing something?

Mine was bare crome molly tubing on the ends and in the middle. Maybe it's something to keep it from rusting??
It doesn't need a coating to run smooth and free in the delrin.

 

[MarkW]

Greg,
That was the center rudder control support where the washers were shown.
I don't believe the outside rudder control support or the flap delrin get this treatment. Also I think the center rudder support is the only one that gets cut in half. I believe the block are snug by hand but with the leverage of the flap control it is a good snug.

 

[airguy]

Be sure and check the ends of the bar, mine had some burrs around the entire circumference. It appeared they were cut with a pipe cutter, a few seconds on the scotchbrite wheel and they were not tight anymore.

Ditto on this, I found the same thing.

Greg,
That was the center rudder control support where the washers were shown.
I don't believe the outside rudder control support or the flap delrin get this treatment. Also I think the center rudder support is the only one that gets cut in half. I believe the block are snug by hand but with the leverage of the flap control it is a good snug.

The center flap bar support is the F-680, which does get cut in half - or at least it is on my kit (ordered February 2009). The same logic applies to the rudder center support as to the flap center support - you are still removing one kerf-width of material, making it out of round and it will bind when the bolts are snugged. I installed mine with the washers between the blocks and it's happy-happy. The outside supports (flaps and rudder pedals) do not get cut, they are recessed-hole blocks that slip on the end of the round weldment. I knew there was a good reason I take all these pictures as I go!!