MX2 Mystery Unfolds...

I started work on rebuilding the MX2 this afternoon. I immediately noticed a combination of problems that may have been the cause of the funky flight characteristics and the final spin to crash. I had just added CA hinges as the plastic miniature hinges were failing one by one. While I had tested control surfaces before flight after the repair, today I found the range okay, but they were difficult to move. I worked them loose. I subsequently found the elevator servo and one of the aileron servos had stripped gears at center. They would move the surfaces but slipped about center. Curiously, I also found the rudder servo with the same center stripped gears that still moved the rudder, but I didn't put any CA hinges on the rudder and it moved freely. There is no damage to the surfaces that might indicate crash damage, so I suspect the gears stripped trying to move the surfaces in flight.

The repairs moved along fairly easily.

The servo mount board for the elevator and rudder. This piece keeps me from using spars as I will have to slide the ends together side to side, instead of being able to push them together end to end. I will likely run spars crosswise instead lengthwise.

I replaced both 9gm aileron servos even though only the right one failed. The cover for the wires is glued into place and at first I didn't think I could slide extensions I don't have down the wing. I wasn't even sure if there were extensions in the wing already I could plug in. It didn't matter, I like soldering the wires anyway. I installed TP 90MG digital servos and plan to replace the rudder and elevator servos with TP MG19 digital servos. Digital all around, ordered from HeadsUpRC.

BananaHobby's website says the servos are all 9gm, but as can be seen here, the one on the left, the elevator and rudder servos, (one shown here) are clearly larger. They are as big as the MG19's I ordered. The TP 90MG is in the center, the right one is the stock aileron which is a 9gm.

Better seen from the top.

Silvering the tips.

Two soldered and covered with heat shrink.

All 3 leads soldered and shrink wrapped.

While the servos are the same size, I had to cut a little out on the fuse side to fit the tabs in the wing. 

Post cutting the fuse end.

I also had to cut a little from the rotor end to give just a little more space.

Aileron servo glued into place all 90'd up.

I glued the forward fuse halves back together as they were parting and the firewall was loose. I used epoxy to secure the firewall and the wheel base wood to the fuse, and to bind the larger section below the wings together, and foam safe CA for everything else. I dry fit the ends of the fuse together and as I noted above, it won't be possible to easily place spars between the glued parts. I have to think about that a bi, but I think I will go widthwise. I am also trying to decide if I should use the Beacon 3-in-1 glue I have very reliably used with the Cubby, or if I should use epoxy, which might add a bit of weight aft of the already aft CG. Waiting for the MG19 servos and a new prop adapter to arrive (ordered today) from HeadsUpRC before I join the fuse as it is easier to replace the servos into the plate before it is installed. I will need to use an standard 3 blade spinner as the original one is damaged, and requires a custom prop shaft (the original bent). I have written BananaHobby a couple of times (in regards to the MX2 and to cancel another order) and they are selective about responding. The decal and paint on the MX2 peels so easily that anywhere I put packing tape to hold the fuse together will have to have the tape on it permanently or it will pull the paint and decals. Its already looking a bit ratty, and I truly hope it doesn't become another Cubby with funky flight characteristics after these repairs...