Tuesday, June 18, 2013

Yet another fuel tank jig

For the last couple of work sessions I have been struggling with getting the left fuel tank ribs cleco'd to the skin.  The skin is just not pre-bent enough and it requires a LOT of downward force to get the rivet holes to align properly.  The clamping jig I used on the right fuel tank didn't work as well this time and in fact it started to bend the rib flanges/webbing at the base (flat side).  So, I struggled with it and finally came up with a new jig.  This one allowed me to use the center lightening hole with a broom stick to apply the needed amount of downward force.

Edit 8-4-2013  I want to say that I think this jig may be unnecessary.  If you use the cradle with boards supporting the entire length of the leading edge, and then use 2 cleco's in the front and 2 in the aft before you fully seat the skin into the jig you will have a much easier time.  I did this later in the process and described it in a little more detail there.