Pitot Tube - IN WORK (Updated 2/19)

I have been working on the pitot tube design/install process during several short work sessions over the last several months.   I will have information and pics as I get closer to installation of the various pieces of this process.   
I will be using the Garmin GAP-26 Heated Pitot Tube with AOA (unregulated) with the Dynon pitot mount bracket.

More later.


This is the Dynon pitot tube mount.   Here, I'm just filing down some of the corners.

Before cutting the hole in actual wing skins, we practiced on a scrap piece of aluminum.    Here, neighbor Scott traces the hole using the template provided with the mount.   

I used a step drill bit to make the initial holes.

Here's the dremel attachment I used to further enlarge the holes after using a step drill bit.



Practice run worked out well.  Time to move on to the real thing.

This is the template that comes with the Dynon pitot mount.   I used spray on adhesive to secure it on position for drilling and cutting.

First, a drill bit is used to make a hole so the step drill bit can be used next.

Using step drill bit to remove as much metal as possible.

Holes drilled with the step drill bit.   Next, I used the dremel attachment previously shown to make the final shaping.







I had some difficulty inserting the Garmin GAP 26 into the dynon mount.   It would fit, but it was very tight.   Here, I wrapped a piece of sandpaper around my deremel sanding attachment and lightly sanded the interior of the mount until I had a nice fit for the pitot tube.

The pitot tube fits nicely in the mount.     Also seen here is the small piece of angle that comes with the Dynon mount.  It is used to secure the mount to a wing rib to provide additional support.   For a couple reasons I will discuss later, I ended up using a longer piece of angle in place of the one supplied.  

This is how the Dynon pitot mopuint is secured.   Just on the slight chance the mount ever needs to be removed, I wanted to make that possible.    Instead of riveting small support angle to the wing rib.   If this piece is riveted to the rib, it would be difficult to remove the rivets if mount removal was ever necessary.   Using the bolts, I can easily remove the angle bracket, then drill out the rivets that attach the mount to the bottom wing skins and the mount can be removed.   Additionally, for installation, if the angle is riveted in place the mount would have to be installed before bottom skin installation.    For a few reasons,  I want to wait to install the mount until bottom skins are in place.   Also shown here is the larger piece of angle I used instead of what was supplied with the mount.    A couple reasons I had for that: First, because I was using screws instead if rivets, I needed a little more surface area to work with.   Also, if you use the smaller piece of angle it may be more difficult to set the rivets that attach the angle to the mount.  The rivet on the angle would be easy, but the other two could be tougher because the angle piece would restrict access for the bucking bar.    With the larger angle, all three rivets are on the angle which should make riveting a little easier.    During installation, I will set the rivets first then install the screws.   

Pitot tube and mount temporarily in place.   Later, I changed my mind and used AN hardware instead of the stainless shown here.    The stainless screws were fully threaded and I didn't like the fit through the drilled holes in the ribs.

As mentioned above, I changed the mounting hardware from stainless to AN.   I selected a bolt length that provided the proper grip  so that no threads would be in the drilled holes in the ribs.