After the inboard W-1210-L rib’s rear flange was match drilled to the spar’s flaperon hinge bracket, the rear spar was removed to allow deburring of the holes just drilled. Once the holes were deburred, the rear spar was clecoed back onto the rear flanges of the W-1210 ribs and the assembly is now ready for riveting.
Finishing the clecoing of the left wing’s rear
spar onto the aft flanges of the W-1210 ribs.
A quick check revealed the pneumatic squeezer
fitted with a longeron yoke is able to access the rivet holes nicely.
Admittedly, I did not check the clearance at the flaperon hinge … it looks
tight there, but since all the other rivet holes can be riveted with solid
rivets, that is what I’ll be doing and will deal with the hinge later. Using a rivet gauge, it was determined the proper
size of rivet to rivet the rear spar onto the W-1210 rib flanges would be an
AN470AD4-4 rivet … so they will be used in place of the LP4-3 pop rivets the
plans call for.
Squeezing the first of many rivets attaching the
rear spar onto the W-1210
ribs with the pneumatic squeezer using AN470AD4-4
At first it appeared to be a good idea to keep
the wing assembly vertical (as in the above photo) so I would not have to hold
the mass of the squeezer with my still quite sore right arm. While this was a
good idea and did work, it was very difficult and time consuming to keep the vinyl
tubing over the rivets (remember the vinyl tubing trick from a previous post?) and
position the squeezer while gravity is working against you. Tomorrow will try
to lay the skeleton assembly horizontally so the vinyl won’t slip off the
rivets … will just have to tough it out with my sore arm or try holding the
squeezer mostly with my left hand.
The vinyl tubing I’m referring to has been
discussed earlier, but basically is a small piece of tubing a little longer than
the rivet which is slipped over the shaft of the rivet prior to squeezing. The
idea here is as the pneumatic squeezer’s piston begins to pushing out, it hits
the vinyl tubing first and compresses it into the flange of the rib keeping it
tight to the rear spar before the rivet begins to be compressed. This keeps the
parts compressed tightly together before the rivet begins setting. Since the vinyl
is malleable, it just collapses under the pressure and does not interfere with
the proper setting of the rivets. I’ll try to remember to post a photo tomorrow
of the vinyl tubing in use.