3D Rebuilding the Compy MX2.

[Bunky.F.Knuckle]

I have been going back and forth with this since the other nite.... So much, that I started to clean off a storage shelf in my basement, in which I have placed my 35% Carden and 42% Dalton on. I actually have a shop floor, somewhat now! Had to have something to distract me from the MX2 servo locations.... But I still need to mount the Rx, batteries and finalize the engine mounting.

I have decided to mount the servos in the tail. I know that having 12 oz worth of batteries on the nose won't get the CG back in spec. But, guess what else I have up front to shift weight..... I have a big honkin, fire breathing, Falcon eating 3W QS 150. At a mere 8#, it would be easiest to shove it out another 1/4". I have a spinner gap of 3/32" already. So, 3/8" may look like ass, but it will be worth it NOT to glue on dead weight. Plus, this way, I won't have to beg, borrow and plead for some Comp ARF 2.9M MX2 rudder servo trays and mounts. And if this ends up nose heavy again, I can thin the mount by 1/16" at a time. Talk about fine tuning it.

 

[reyn3545]

Sounds like a plan! This 157 CS TS is the first 3W I've owned in 3 or 4 years. They do have amazing power, and it starts very dependably.. can't ask for more than that!

 

[Bunky.F.Knuckle]

Now, just to get another 1.75" servo arm...... Or do I dare go 2" or step back to 1.5"???

 

[Bunky.F.Knuckle]

I went thru with it. I cut 2 holes in the back of the MX2 for rudder servos. Have some 1/8" backer plates drying in the fuse now for the servos. Had Chad and Tash @Taildraggerrc send me a pair of 2" servo horns to fit my Savox 2231s. I would hope that a push pull set up with 2 servos at 555oz would be enough for the small MX2 rudder. If I could KE loop the airplane on 8911s and again on 2270s in pull pull config, surely the 2231s will be enough!

I didnt want the servos back that far, but that is where it really looked the best at. Plus, a shorter linkage will be less prone to bend or break when I touch the rudder on the ground.

Considering I have broken 2 6" long SWB (supposedly) titanium turnbuckles. 1 by just barely touching the ground on my 330SC and the other was when the vertical fin blew off in flight.

Then I finished up installing my fuse protectors from a fellow in Estonia, I think. They are cut out reverse on a vinyl cutter and plotter. Had to do just hint of trimming for the fwd anti rotation pin.

 

[Bunky.F.Knuckle]

Started programming rudder servos and installing them. Looks like there may be a hint of flex with tail mounted servos.... I may have to make up some sort of bulk head for the tail for the servos. Can't have that flexing back there. But 4-40 pushrods in 3mm ball links don't cut it. You wouldn't think that .009" is that big a difference in sizes, but it surely is.

Ordered some 70mm long 3mm thread turnbuckles from HH just a bit ago. Hope they will be here on Thursday. That will give me Friday to play, and then Sat morning drive to a wedding in Indiana. By friends oldest daughter is getting married. Gonna be a 10 hour drive, round trip and 4-6 hrs there. Gonna be a long ass day, I tell ya what.

 

[reyn3545]

The holes in the rudder horns are definitely drilled for a 3mm bolt, and a 4-40 will wobble justenough to annoy you. I usually use titanium 4-40 turnbuckles.... I put a 4-40 ball link on the servo end, and a 3mm link (supplied by carf) on the rudder control horn end. I also do the same for ailerons and elevator. Works great an eliminates any slop.

 

[reyn3545]

Can you send me a link to the guy who supplied the fuse protectors?

 

[Bunky.F.Knuckle]

I got his info from Craig Beavery in England. The fellows name is Norman Toth.

Craig is the cat who does alot of Krills testing on the other site. I dont think he has a screen name here.....

 

[Bunky.F.Knuckle]

Dur...

 

[Skyluc]

I got his info from Craig Beavery in England. The fellows name is Norman Toth.

Craig is the cat who does alot of Krills testing on the other site. I dont think he has a screen name here.....

His mail is
normanair1@gmail.com
He made me some fuzz protectors for my krill extra and they are very fine