Sunday, February 21, 2010

Reinforcing my hanging rudder pedals

I came full circle on which rudder pedal setup to use. I had bought hanging rudder pedals from Dave early on in my build process. Then came the discussion of why they wouldn't be approved in Europe. The concern is that being attached to the hanging mechanism from only one side at the top and bottom is weak due to the twisting forces introduced when using them. I discussed this issue with my local EAA Chapter 80 Tech Counselor and he agreed that over time there might be a problem of the weld breaking due to the design. He related a story about another local Chapter 80 member and his RV6. The early RV6's had a similar hanging design. The twisting side loads from using the pedals eventually broke the weld and near disaster happened. Our fellow chapter member was on take off roll when the pedal broke. He did manage to stay on the ground, but did significant damaged his aircraft. Van's actually changed the rudder pedal design because of this incident. They added another vertical tube to the other side of the rudder pedal to make a "box" frame that evenly distributed the loads when using the pedal.

So, after I heard this story I went about trying to "fix" my hanging pedals in the same way. However, after a conversation with Dave Thatcher, it was determined that I could not use the "box" design because the additional vertical tube would interfere with the fuel tank that sits just in front of the pedals in the CX4. Darn!

By this time Dave had come up with his floor mounted rudder pedal setup and I was headed in that direction. But I’m a little hard headed when it hits my pocket book and I kept coming back to the hanging pedals I had already had purchased. Why throw away good hard money when some of the early builders who have the hanging pedals say they like them and don’t intend to switch. So, after further discussion with my Tech Counselor, we came up with a plan to reinforce my hanging pedals.

Click on image to enlarge



You can see in the photo’s that we welded a couple of triangles to both sides of the upper joint and welded a strap to the lower joint to help take the twisting forces that will be applied when using these pedals.





Are these necessary? Maybe not, but now I personally have more confidence in them. As they say; “It’s my butt in there”. Be assured, checking these welds will still be on my annual inspection list!

 

Sunday, February 7, 2010

That took longer than I thought it would!

I finally finished my forward access panels. It took longer than I thought it would. Mainly because it is tedious work.

Once I got the flange made and shaped the way I wanted it, I then needed to rivet it to the forward side skin. I postioned it on my workbench near the edge and clamped it in place. I marked the position of the holes and drilled through both the skin and the flange at the same time. After drilling the first hole I used a cleco as another way to hold everything in position. I used a 2nd cleco in the second hole and then drilled the rest of the holes.


Click on image to enlarge

I used a similar method for drilling the holes for the cover panel and the flange. For instance, after the first hole was drilled, I used a screw and a nut to hold the position of this hole while I drilled the second hole and used another screw and nut while I drilled the remaining holes.

The nut plates were way to tight, so after a call to my friend and technical counselor, I used a tap and carefully opened them up slightly. If you over do it and make the nut plate too loose, just simply use pliers to squeeze it back to the tightness needed.

I took everything over to my friend's house and used his dimple die and rivet squeezer to put everything together.


I was not pleased with the gap around my cover plate, so I made them over again. My second attempt is better, but I won't be winning any Lindy awards with them either. It certainly looks hand made to me.



I'm glad I made these access panels and I'm glad the work is done.