After the edge preparation of the previous days it's time to matchdrill the left elevator.The left elevator is pretty much the same as the right elevator. The only difference is the presence of the trim tab.
First matchdrill the reinforcement plates with the the nutplates to the rear spar.
Then edge preparing and fluting on the end ribs. As you can see, the ribs rest nicely against the table top. The flanges of the E703 are a bit wider towards the end, so don't get fooled when straightening. That's why in the picture, the end is over the table end.
Mate the 703 and 704
Just like with the right elevator, here also, the holes do not align well once clecoed to the skeleton.
Then matchdrill the end ribs to the rear spar. The best here is to use the 12" drill.
Then position E713 and E714, counterbalance weight and skin in place. Similar story as before, terrible alignment when putting these in place.
With a bit of work, you get the clecoes in place.
To drill the 2 #10 holes through the counterbalance weight, I used a wooden block to secure the construction to the workbench.
Then drill the 2 holes using the pilot holes as drill guide. First dril #40, then #30 and finally with #10.
Lot's of lubricant are required as lead is a terrible material and clogs the drill constantly. I received my tapping fluid from avery last week and this works much better then the normal air drill oil.
The holes align very well in the other end. Plenty of space for the washers on both sides.
Then matchdrilled all holes of the skin to the ribs and spar. There is an additional support rib in the left elevator where the trim tab piano hinge attaches. This part is the E-606PP. Remember this number, there is a hole story coming up about it later on.
I'm really happy with the V-blocks jigs. It takes a bit of time to make them but it's really worth it. Much easier to hold everything in place.
I still have a lot of problems with my "tennis elbow". I found a new way of dimpling that is much easier and lighter on the muscles in my right elbow.
I clamped the pneumatic dimpler in the vise. Much easier. I'll do this again.
Then dimpled #12 the holes in front of the counterbalance skin using the vise dimpler set. Tightening the nut will press the material in the dimple dies.
Then countersunk the rear spar connecting points . This is again where the elevator horn attaches so the rivets must be flush.
The middle 2 are done with the countersink cage. The outer 2 manual.As you can see, the bottom one turned out not that smooth. The rivet fits nicely so I decided not to mess with it anymore.
Also countersunk the counterweight with #10.
Since I was out of work after that I had a look at the bending process for the elevator tabs and made a first effort on drawing a bending line perpendicular the to trim tab cutout line.
I also dimpled all ribs and skin as it said on the plan.
This is where I found out why Vans tells you to read the plans through completely, re-read them, and then start working.
In my enthusiasm of dimpling, I dimpled all ribs and skin... just like it said in the plan description.
Then you find out 4 or 5 lines below. 'Now, countersink the top flange of the E-606PP and dimple the bottom flange"
"AAAAAaaaaaaahhhhhh !!!" followed by a lot of nasty words again.
I first thought of scrapping the piece. Then sent a mail to Vans support asking what to do. Gus Funell told me to use the dimple dies in reverse and squeeze back the dimple until the material is centered again.
This needs to be done with the dimples and not with the flat dies because the aluminum will spring back when bent so you have to slightly overbend.
I got new courage and squeezed back the already made dimples.
They looked reasonable but I was not satisfied with the flatness of the material around the holes. After all, this will hold the piano hinge for the trim so it better be nice and flat.
I decided at that point to use the flat dies for rivetting in my pneumatic squeezer and apply some force to the holes. Did a couple of them, and indeed, worked out great !!, nice and flat. Wow... looks like we are going to save this piece after all !
After squeezing all of them, I felt convinced all was fine now... Until I layed the piece down on the workbench to check the straightness.
Recovering ??? Forget it !!! Straight to the scrapyard...
What I didn't realize was that the flat dimples squeezed so hard that the material underneed got pushed in a little and extended the surface at that spot. Doing this in all the places made a big difference in the end and created a nasty bend in the material.
No way to recover from this... straight to the bin.
It had to happen sometime so now I can officially say that I ruined my first piece and will order a new one.
I will hang this one to the ceiling of my workshop as to remember what stupidity leads to.
Lessons learned :
1. Don't flatten aluminum with flat dies on the pneumatic squeezer. You may get away with doing it at one local place, but you will be punished for doing it multiple times on the same piece.
2. Read the whole description of the plans and read them again before starting. Even if the piece is identical to the part you just completed.