Tuesday, February 4, 2014

Roll Bar Assembly Mounted

Work in the shop was a mixed bag of small events that paved the way for the fitting of the roll bar structure onto the RV-12 fuselage. The first chore of the day was to finish up riveting the cockpit light bracket on the forward roll bar frame and rivet the canopy latch onto the aft roll bar frame. AN470AD4-7 rivets were used on the canopy latch and AN470AD4-6 and 5 rivets were used on the cockpit light bracket.
Finished forward and aft roll bar frames riveted into the F-1231E splice plates with canopy latch and cockpit light bracket in place.

One of the small tasks that needed tackled prior to mounting the roll bar assembly was riveting the longerons onto the bottom of the roll bar mounting plates.
Riveting the left longeron onto the bottom of the left F-1205B roll bar mounting plate.
Earlier in the week, a trial fit was made to see if the roll bar assembly with bases would align with the bolt holes in the roll bar mounting plate. They did. The plans call for riveting the roll bar assembly together first, then place the assembly onto the roll bar bases after they have been bolted onto the mounting plates. The roll bar bases are a VERY tight fit in the bottom of the roll bar assembly.
Knowing some builders have had issues with the finished width of the roll bar, the DOG Aviation assembly department decided to try a different tact.  Rather than rivet the roll bar components together first, then force it onto pre-installed F-1231D bases … decided to Cleco the entire roll bar assembly together, then install the F-1231D roll bar base inside the structure.
Using Clecos to attach the F-1231C roll bar strap onto the aft roll bar frame.
Attaching the F-1231B roll bar strap to the forward and aft roll bar frames with Clecos.
Clecoed roll bar assembly ready for the F-1231D roll bar bases to be inserted.

After inserting the roll bar bases inside the roll bar structure, the whole assembly was then bolted onto the fuselage and the fit was perfect.
Jan helping to hold the roll bar assembly in position on top of the F-1205B roll bar bases as the mounting bolts are installed and tightened.

I see no problems doing the roll bar this way because the nine holes in each of the left and right forward roll bar halves define the position of the roll bar base inside of the structure. So the entire roll bar assembly will be riveted together in position and the sides of the F-1231D roll bar bases will be match drilled in this position as well.

Before beginning the riveting of the roll bar assembly, there were a couple of items that need to be done. There is a support frame that needs to be attached between the roll bar assembly and the canopy deck, but the Clecos holding the canopy deck onto the longerons were in the way … so just went ahead and riveted both canopy decks onto the longerons.
Riveting the F-1234L canopy deck onto the left longeron.
Mounting the F-1254-L support frames between the roll bar assembly and the left canopy deck.
Support Frames and roll bar assembly in position and ready for riveting.