More Hardware, and Bellcrank Setup

Today (saturday and sunday roll up) I spent some time playing with the new hardware I bought from ACS. I had ordered a bunch of new bolts. KP3’s for the Aileron Slave strut arms, AN665 forks for the drag wires ect. I also bought some 0.063 4130N to make backing plates for the Aileron hinges that I will rivit 1/4-28 nut plates into so that I can tighten the aileron block down the road without cutting a hole in the fabric in the future.

I also spent a bunch of time playing with the geometry of the 90 deg bellcrank location. It’s a rather tight area between the drag wire and the bell crank. I studied the photos on raven’s website a bunch and finally came to the conclusion that that the aileron hinge needs to be on the inboard side of the I-strut hole. I also figured out how far inboard after figuring out where center was. The edge of the outboard side of the aileron hinge block will be set 0.3125″ inboard of the I-strut hold centerline. And the aileron attach bolt centerline will be 0.8125″ inboard of the I-strut hole centerline. With the aileron hinge on the inboard side of the the I-strut hole pushes the 90 deg bellcrank past the I-strut 1/4″ doubler by about 0.5″ so I will have to glue in a small amount of 1/4″ to extend the doubler a little to accomdate the new location of the 90deg bellcrank.

After figuring all this out I realized I had made a mistake assembling the wings originally. The ribs unfortunatly matter which way is up on the lowers. This wouldn’t normally matter on a symetrical rib (and doesn’t for the top wing) but the way the truss is set up there happens to be a nice gap as the truss goes the opposite side for the control push rods. One wing I got resonably lucky and only screwed up 2 ribs the other wing I screwed up 3 ribs.

I have two courses of action here both are just fine one is easier both are likely the same strength.

Option 1: Cut the last trust cross member and install one going the other way (really easy) Likely my choice
Option 2: Cut the last truss cross member and sheet the last rib truss area with 1/16″ ply cut the hole for the control tube

Time spent 6 hours
Total time spent 70 hours

2 Responses to More Hardware, and Bellcrank Setup

  1. macwolf says:

    Howdy. I came to a different conclusion about the aileron hinge location, and have it on the outside of the i-strut hole – seems to work better with the location of the bellcrank/drag wire spacing, and keeps the bellcrank nicely centered on the i-strut doublers…. keen to understand how you worked it out (in case I got it wrong – heh)

  2. acropilotbret says:

    yeah I went with it on the inboard to get the bellcrank to arm to sit square with the hinge arm i would have to place the bell crank with in 1/8″ of the wire and I didn’t like that. I referenced robs picture on the Raven website and he confirmed my suspicions on Andy’s wings he put the lower hinge on the inboard and the upperwing hinge on the out board. Also looking at the Model 12 they do the same.

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