Week 242 - Fin/Rudder gap, Horz Stab Gap and mod, Oil door

Hours to date: 2400.25

I'm happy to report that the cowling is done (virtually!)

Onto some other jobs.

Following the manual technique for making an even 2mm gap in the fin to rudder junction works very well. Make sure to use more runny micro than usual - although even mine ended up with some tiny air bubbles here and there.

I finally got to finish the oil door. The hinge has to be as far away as possible from the opening for the door to swing up and clear the edge.

Just some body filling on the flush rivets and a little more primer and the oil door job will be done.

Onto my tailplane securing mod. As well as the pin I am making a fail safe connection using a piece of solid carbon sheet bonded into the tailplane and another into the root end of the fuse. There will be a thread cut into them both and then a dome head allen bolt will be screwed and Loctited into place from below (on the outside).

Also with the pin rather than having it go underneath the elevator pushtube I am running the pin from the front instead - thereby eliminating the possibility of the pin and its nylon sleeve from being worn and failing - as happened on a UK Twister a while back (see my previous post about it from February 2014).

As I plan to keep my Twister permanently rigged then the internal pin is not a hassle for me - it would be if you derigged often as you have to take the rudder off to get to the pin.

The other job I did was fill the gap between the tailplane and fuse - again as per the manual's technique. We will see how that turns out next post...

Leveling top of fin using a sheet of Ali (waxed) and a heavy weight on top with runny micro underneath as a filler. Make sure you level the fin top first will a spirit level.

Cowling all done and with a coat of white primer to see how it looks when it is the same colour as the fuse.

Nice curves don't you think?

Rudder after same treatment as the fin - the runny micro gives a smooth uniform finish.

Even 2mm gap between the rudder and fin now.

Bonding in a solid lump of carbon for the tailplane fail safe connection.

This shows the location. I made it slightly too deep so I can sand it down flush later.

Inside - the pin is now going in from the front rather than the back as before.

Masked off tailplane root with packing tape as a release and then flock on the tailplane in the honeycomb to fill the gap. All pins and exposed stuff that is not bonded is waxed too.

Ditto. Using micro and same technique as the rudder/fin on the elevator gap.

After pushing together (and putting the pin in). Will be sanded back to profile when set.

Oil door finally finished. Just have to fill, sand and then prime the flush rivets and we're done.

Oil door gives good access to the dipstick.

Good gap between the cowl and door when open.