Flap Support Frames (page 1)

The Flap torque tube is supported through a couple of bearings welded to the Flap Support Frame and the Wing Root Torque Support tube.  The bearings are simply some 7/8" diameter tube and the Flap Torque Tube which is 3/4" diameter is a slip fit inside the 7/8" bearing tube.  Even though the plans do not show it, there must be some means of greasing these slip fit bearings.  In looking at the prototype photos and the wing log I bought from Mike Meador, I see that grease fittings have been attached to the 7/8" bearing tubes.

I bought some grease fittings at the local Auto Zone.  These were threaded with 1/4 - 28 threads.  I also picked up some 1/4 -28 nuts while I was there.  

After welding the nut on, a small hole was drilled through the 7/8" bearing at the center of the nut to allow the grease to enter the bearing.

Here is the bearing cut to length and the grease fitting screwed in place:

The bearing is attached to the Flap Support Frame by a couple attach plates with 7/8" holes in them to accept the bearing.  The holes in the attach plates were made with a 7/8" bi-metal hole saw with drill mandrel at the center.

I found it easiest to leave the attach plates uncut from the sheet of 4130.  I marked where the holes should be and drilled them first.  The attach pieces were then cut from the sheet and shaped to their final shape.

Here is a picture of the finished bearings ready for welding to the Flap Support Frame:

Aligning the bearings properly on the Flap Support Frame for welding is very important.  Here is a picture of the first one in place and ready to weld:

The picture above shows several of the items used to assure alignment.  

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