Elevator’s Installed

Time: 6 Hours

I got started today by retrieving the elevators from my storage so that I could install them and drill the horns. Before startinging I removed the VS so I could clean, debur, scuff and prime the forward spar attach bracket and spacer. When that was done I grabbed the left elevator and put it in place with my temporary pins. I needed to trim the elevator skins where they met the counterweights of the elevator.  I marked them and cut the skins and filed it down to a good edge.  I repeated the process on the right side. 

      Next I needed to trim the lower flange of the rear spar on the HS to allow for clearance on the elevator horns. 

 I marked the flange with a sharpie and then removed both elevators and the HS from the fuselage. I also removed the hinge so that it was not damaged during the cut.  I needed to be real careful when I cut this so that I did not damage the spar support bar underneath. I grabbed a scrap piece of .025 and drilled a hole so that I could Cleco it into position to protect the bar.  

 The cat went pretty easy with no damage, I cleaned up the corners, touched up the primer and reinstalled the hinge. 

 I put the HS back into position and rebolted it down.  Next up was the process of drilling the bolt hole through both horns of the left and right elevator for the center hinge bearing. This bolt is a 1/4″ AN4 but I would start with a #40 hole. To get the whole centered I used a drill bushing that I bought from McMaster-Carr that had an O.D. of 1/4″ and a #40 I.D.  I did have to sand down the outside edge just a little to get it to fit inside the bearing. I did this by chucking the bushing in my drillpress and using sandpaper as it turned. 

   I reinstalled the left elevator only so that I could drill its horn. The process is fairly simple, you just need to put the elevator in line with the HS by clamping the counterweight so that it is even with the HS.  

   Once it’s in place in aligned I slid the bushing back in the bearing and slid it tight up against the elevator horn.      I grabbed my 12″ #40 drillbit and drill the hole in the horn. 

 I removed the elevator and enlarged the hole with a #19 drillbit followed by my 1/4″ reamer.  

 I repeated the process on the right side.  

 I grabbed the AN4 bolt, nut and a few washers to attach the elevator horns. There is a gap between the horn and the bearing and it varies due to the welding. You just use a combination of washers to fill the gap. I ended up with 3 washers on the left and 2 and 1 thin on the right.  

 Putting these washers was made easy with my washer wrench set I bought last year.  

 With the bolt tightened down I was able to move the elevators together which was pretty cool.   

       A very common thing is to have the elevator horns be off a little as the welding process can vary from lot to lot. Mine was no different from other builders  

   The bottom of the horns is where the elevator controls connect via a rod end. The measurement is 3/8″ up and 3/8″ back to give good edge distance. You just choose the aft most horn for these measurements. That way the edge distance on the other horn is even better. In my case the right horn was the aft most one. I marked the whole and drilled a #40 hole and followed that with my 3/16″ reamer. Since there is a gap between the two horns the plans how do you make a wood drill spacer to help align the drillbit for the other horn. I grabbed a piece of oak and sanded it down to just fit between the two horns which was approximately 7/8″. I drilled a #12 hole in the wood block and slid it into place with a clamp. 

 I used that would block to drill the left horn to match the holes.  Now they are ready to connect to the elevator controls. Before that can happen I needed to put the center control tube in place. This tube will rotate left and right to control the ailerons and will house a control are in the center for a forward and aft movement to control the elevators. It was a little tough getting it into place through the center section rectangular hole. Once it was through I added the rod ends to it and temporarily bolted them in the supports.  

   It was getting late so that’s where I decided to call it a night.l after another great day in the hangar. 

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