Today I went ahead and countersunk the trailing edge wedge after much setup and practicing on scrap.
Here is a picture of the setup:
I followed the section 5 instructions, but used the cleveland tool to aid in countersinking perpendicular to the faces. I have seen others incorrectly countersink along the chord of the wedge, but this is incorrect. The dimples are parallel to the skin, and therefore the surface of the wedge, so the countersinks need to be perpendicular to the wedge. I drilled a #40 hole into the cleveland tool, as support for the pilot, as i found it was easy to get chatter without some support for the pilot below, and i used the Cleveland Modified Countersink.
I initially set the cage so that a rivet sat flush (or at least mostly flush as the hole it is in is not normal to the face of the wedge). I then went approximately 10 thou deeper. This allowed the dimples to sit nicely, and took the holes so that the aft edge was **just** knife edged, without making the hole oval. This took a few practice countersinks on the scrap wedge to get this depth correct. The wire stops the cage from spinning to allow me to guide the pilot into the centre of the hole.
When doing the countersinking, the pressure applied really affects the depth of the countersink - so i focused on keeping the same pressure on the drill press handle each time, and measured the countersinks periodically, as i had read they can change depth as the cutter tightens on the thread. In fact, i had the opposite. At one point it looked like the pilot was wobbling, and when i checked it, it needed to be tightened back in a little. In between every hole, i blew the swarf away with the air gun - saving weight!!!
Here is a couple images of the finished product.
Today i also test fit the VS cradles my dad made up for me - with a bit of easing of the front cradle they fit well. This should help the riveting of the VS together. They are simple chipboard shapes made by tracing around the ribs, and adding a gap. Then they are covered in duct tape, and some foam door and window seal applied.
Here is a picture of the setup:
I followed the section 5 instructions, but used the cleveland tool to aid in countersinking perpendicular to the faces. I have seen others incorrectly countersink along the chord of the wedge, but this is incorrect. The dimples are parallel to the skin, and therefore the surface of the wedge, so the countersinks need to be perpendicular to the wedge. I drilled a #40 hole into the cleveland tool, as support for the pilot, as i found it was easy to get chatter without some support for the pilot below, and i used the Cleveland Modified Countersink.
I initially set the cage so that a rivet sat flush (or at least mostly flush as the hole it is in is not normal to the face of the wedge). I then went approximately 10 thou deeper. This allowed the dimples to sit nicely, and took the holes so that the aft edge was **just** knife edged, without making the hole oval. This took a few practice countersinks on the scrap wedge to get this depth correct. The wire stops the cage from spinning to allow me to guide the pilot into the centre of the hole.
When doing the countersinking, the pressure applied really affects the depth of the countersink - so i focused on keeping the same pressure on the drill press handle each time, and measured the countersinks periodically, as i had read they can change depth as the cutter tightens on the thread. In fact, i had the opposite. At one point it looked like the pilot was wobbling, and when i checked it, it needed to be tightened back in a little. In between every hole, i blew the swarf away with the air gun - saving weight!!!
Here is a couple images of the finished product.
Today i also test fit the VS cradles my dad made up for me - with a bit of easing of the front cradle they fit well. This should help the riveting of the VS together. They are simple chipboard shapes made by tracing around the ribs, and adding a gap. Then they are covered in duct tape, and some foam door and window seal applied.
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