Worked on This and That - 7 hours

Today was the first big day on the plane in quite a while. I managed to order a few needed parts and tools last week, which put me back on track for the project. First off I got to work on the VS808pp spar doubler. This section has given me a bit of grief for a variety of reasons; 1 - Countersink depth, which is a little bit of a trick to get. 2 - Setting those rivets that are in the VS-410PP brackets that are soo close to the vertical portion of the bracket. 3 - Removal of poor rivets is extremely difficult through the thick material. I've wreaked a piece trying to punch out a rivet, without the use of the handy tool that I was told about after the fact. So...Round Three...Here we go.

I set out by cleaning up the entire piece...Something that I have now mastered. I used a Dremel with a small sanding drum on the holes and on the inside radius's. I then used a file to break all other edges.

I then set up the countersink using a test piece that I have made and dimpled. The correct setting results in a countersink depth so that a 426AD4-X rivet sits just ever so slightly below the surface of the material being countersunk. Note to self: Order more countersink cages!

Now, on to the next piece, The rudder counterweight. Again the original one was countersunk way too deep. Changed the bit on the cage and re-set up the countersink. After much monkeying around, the proper countersink was done. Note to self: Order more countersink cages! I tried to mark out the area where the six rivets on rudder counterbalance rib interferes with the weight. Note to self: Next time mark the six rivet holes on the weight before you set rivets into the counterbalance rib.

I then used files to remove areas of the lead weight that interfered with the counterbalance rib and rivets. I also cleco'd on the horn brace.

Next, I moved on to the elevator trim.  After reading a few build logs about hove everyone notices that the dimension callout of 1-3/8" is wrong (See Electric Trim Assembly Detail on drawing #4). I found that a dimension approximately 1.275" is closer to the correct one. 

The above picture shows how the trim sits if I used a 1.375" dimension

The above picture shows how a reduced dimension allows the trim to sit centered in the opening.

Building tools

A handy tip that I learned from one of the guys at the EAA meeting is to build some guides for both drilling operations and rivet removal operations. A little drill guide using a piece of round bar with either a #30, or #40 hole is a handy tool that ensures that when drilling a hole with a hand held drill, the drill bit is perpendicular to the piece. If you can have a tab welded to the side it will allow you to have a place to use a clamp on it.

A similar guide is great for using under a piece when you need to use a punch to remove a rivet.  The trick is to have a hole in the tool that is just slightly larger than the shop rivet head. If you ever need to punch the rivet out, the tool used would support the aluminum around the rivet and is helps you avoid bending the aluminum while driving out a particularly stubborn rivet.

I had ordered a few round bar pieces last week. All were 2" long and I got some 1" diameter and some 1-1/2" diameter. In retrospect....the 2" length is just too long.

I think I will re-order some pieces that 1" long and get some 1" dia, and 1-1/4" diameter. and use those as my drill guides. (Update....This is an excellent size 1" diameter and 1" long. Drill some on center, and some off to one side. The ones drilled off to the side come in handy for those tight areas)

I decided to use my 2" x 1-1/2"dia piece to make a guide for punching out AD4-X rivets. Driving these rivets out of the thick spar doublers has been a cause of much frustration for me. Hopefully this tool will safe grief for me in the future. I started out by marking center on a piece. I then set up the drill press and made a pilot hole with a small 1/16" bit.

 I then enlarged the hole with a 15/64" bit. Turns out that this hole size will allow removal of both a AD4-X and AD5-X rivet.