Rotor Mods:

Ball Joint Repair Mod
Author: MicroBuilder
Author Email: Micro Builder at RC Universe
Specs: N/A
Material Required: CF Rod, micro size drill bit
Downloads available:
Notes: I've got a little fix here for anyone who's broken a ball off their mCX.
I broke the ball off one of the arms of the swashplate, and CA wouldnt hold it.

I drilled out a hole in the broken ball end, and in the end of the arm of the swash where
the ball should've been. I then put a peice of CF rod in the drilled hole of the broke
ball, trimmed the CF to length, and then put the CF and ball in the drilled hole of the
swash plate arm. Now the ball is attatched the swash arm by CF, not plastic, and its
very strong.
It takes a small drill bit (.60mm / .024" ) and some small CF (.65mm / .025" )
and drilling the hole in the ball is a pain, but its worth it, as this ball will never break off.

End Play Removal Mod
Author: Piper J3
Author Email: Piper J3 at RCGroups
Specs: N/A
Material Required: Canopy Glue, Brass Washers
Downloads available:
Notes: Add Canopy Glue to ball link on upper blade to prevent shearing off from flybar during crash. See photo - glue is white but dries clear.

Found brass washers from McMaster-Carr that are 1/8 OD x 1/16 ID x 0.018 thick. P/N 95395A101 ($3.83 for pack of 25) to be used to eliminate end play on both upper and lower blades. See pics.

Fast Flight Mod
Author: Martyn McKinney
Author Email: Martyn McKinney at RCGroups
Specs: N/A
Material Required: CA Glue
Downloads available:
Notes: With a pair of sidecutters, I cut the flat portion of the right-hand arm going to the right hand servo (PASSENGER SIDE IF YOU DRIVE IN NORTH AMERICA) extending from the swash, in half.

There is a center reinforcing ridge on the top of the remaining arm (stub) which I removed with a sharp X-Acto knife.

I then mounted the cut off piece, still attached to the servo, on top of the stub connected to the swash and glued it with a drop of CA.

I didn't even have to remove the body and the trims barely needed adjusting.

The fix took about 5 minutes.

BE CAREFUL WITH THE CA GLUE! Don't let any get into the swash.

Fast Flight Mod 2
Author: Dealwagon
Author Email: Dealwagon at RCGroups
Specs: N/A
Material Required: Spare Set of Upper Rotors
Downloads available:
Notes: OK, so I wanted some zip with my mCX. I bought a spare set of upper rotors, then drilled the swash (while on the mcx) and put the screws in.

Here's where I departed from the previous methods. I took an old cx2 rotor, heck you could use carbon (which I may buy some and redo this) and I cut 4 SMALL sections. Then I used CA and glued them on top of the lower head ball rod guide arms. This looks a little more stock and mainly, I couldnt find any tubing that small.

The screws were a little loose, so I am trying to find the perfect thing to dip them in thats quick and coats them enough.

Now this thing zips now. IF you havent done this, do it. I CANNOT believe the difference this makes.

Thanks to those that came up with this. It is definately a MUST DO MOD if you are doing anything to your mCX.

Flight Mod
Author: Xrayted
Author Email: Xrayted at RCGroups
Specs: N/A
Material Required: Walkera 4#3 paddles,flybar weights
Downloads available:
Notes: This heli moves slower in some directions partially because of the poor angled position of the servo to swash connections. I removed the PCB board and cut the frame mounts in half to move the board all the way up against the frame. This puts the links to the swash much closer to the correct 90 degree position and gives linear swash throw in all directions.

You must remove the lower canopy mounts as well as snip off the lower portion of the aileron servo arm because it will hit the front of the landing gear in the full down position. The battery must also not be pressed into the holder all the way either or it migh contact the servo gears. Some of my batts fit all the way just fine and others are a little close for comfort. Im using a cut down MIA Walkera 4#3 canopy so I didnt need the lower canopy mounts anyway for my application.

CAUTION....the above mod can cost you some expensive parts if you screw up so do this at your own risk!!!!

Next I cut the flybar down much shorter and are using Walkera 4#3 paddles as the 4#3 flybar is the same size.
The shorter, lighter flybar will cause the heli to death roll so I added tiny little ally MIA flybar weights made for the 4#3 as well. The flybar now weighs just a bit over the stock flybar weight but the flybar will not smack the blades no matter what and the shorter flybar takes longer to take the heli back out of FF.

The result is a lot better and faster cyclic commands in all directions with no blade clack no matter how hard I jerk it around. Its not so fast that its no fun but definitely more agile than my stock heli.

Fly Wheel Weight Removal Mod
Author Email: J-MICHAEL at RC Universe
Specs: N/A
Material Required:
Downloads available:
Notes: I wouldn't recommend cutting the spokes on the gears down to two spokes... I do recommend though on cutting 4 out, and leaving 4 though... There just as strong with 4 as with 8... And less stress to the motors... It will give the motors a bit more power thrust to the rotors, while also providing a slight longer running time, while also helping the motors from generating heat...

Forward Speed Mod
Author: MMCGinnis
Author Email: MMCGinnis at RCGroups
Specs: N/A
Material Required: Spare Set of Upper blades, .035 CF Rod, CA
Downloads available:
Notes: Cut the linkage balls off of the extra set of blades. File the ball peg length so the leg and ball are about .09 inch long.

Disassemble your heli as follows:

Start by loosening the two screws on the drive gear that is on the bottom of the heli.
This allows you to pull the upper blades along with the inner shaft out the top of the heli.
Pull the inner shaft bushing and holder off the top of the outer drive shaft.
Remove the lower blade linkages from the swashplate.
Remove the lower blades secured by two screws.
Loosen the two screws that secure the lower blade holder to the outer shaft.
Slide the lower blade holder off the top of the outer shaft.
Remove the two servo linkages from the swashplate and remove the swashplate.

Now that he heli is disassembled we can start the mod:

Glue one ball to the tip of the existing linkage ball on either side of the swashplate, extending the effective swashplate ball outwards by .09 inch. You now have a swashplate with two balls on each side. Only the outer ball will be attached to the linkage when we reassemble the heli.

If you look at the pictures, you will see that I added these two balls to the existing balls, in such a way to make sure that the 4 balls lie in a straight line. After I assembled the heli, I noticed that the swashplate is not a bit loose, due to the fact that the linkages are now parallel. They no longer have to be as long to reach the swashplate. Strangely, my heli does not feel loose in flight. It feels just as locked in as it did before. I do suggest a simple fix for this that I have not yet done, and I do not plan to do it until I break one of the balls off the swashplate from some future crash. It flies so well now, I don’t want to take the time until I need to. To correct the issue, simply glue the balls on at a slight downward leaning angle. This will place the balls further away from the upper blades, taking up the slop in the linkages.

The next step is to extend the 4 pegs on the lower blade shaft holder so the blade pitch linkage will remain captured by the pegs after they have been moved outwards on the swashplate. This is really quite easy to do. Take the carbon rod and score the outer circumference about .05 inch from one end with a dremel tool and a cutoff wheel or something similar so that the rod piece is just barely hanging on the remainder of the rod. Put a tiny drop of CA on the tip of the .05 inch rod piece and glue it to the end of one of the 4 pegs on the blade holder. Once dry (zapped), finish off the cut with the dremel or simply break it off. Do this for the 3 remaining pegs.

Lastly, remove about 1 mm off the top of the swashplate anti-rotation pegs. Failing to do this could result in your extended swash balls coming into contact with these pegs. This is especially important if you took my advice and glued the balls on at a slight angle. I just touched my cutoff wheel to them to shorten them a bit.

Reassemble your heli in the reverse order described above. Take care when tightening the two screws that affix the lower blade holder to the outer shaft. If you do not get the two screws to go into the center of the holes in the outer shaft, you will booger up the holes. This will also cause more or less slop in the blade linkages depending on weather you are too high or low here.

You should notice the lower blade linkages are near parallel now.
Bench test the linkages with your remote to check for binding before you fly by slowly spooling up and moving the cyclic to all extremes. If there is no binding, it’s time to fly.
Pop the heli up into a hover and you'll immediately notice the heli is hard to move slowly. It wants to go everywhere. I found that 30% exponential on the elevator and aileron fixed it right up. Now it still flies exactly like stock around center stick, but flies quite fast at the outer edges.

You might also try mixing the aileron and elevator with the throttle so that when either aileron or elevator inputs are given, the throttle is increased About a 9-10 % mix seems to work. This is not necessary but it helps with or without this mod to keep the heli from descending when you apply cyclic inputs.

Extra note: I’ve now flown 4 batteries on this mod will no ill effects. I do have a fear though. I am concerned that the tiny drop of CA glue that is securing the extra balls to the swash plate will someday give way and I’ll be seeing my beautiful heli come crashing to the ground. While a preflight check should help elimate my fears, I suspect one will break off quite easily in a crash. Nothing that can’t be fixed, but I wonder if there might be a better glue to use here. Maybe contact cement or epoxy. I think Contact cement might work best as it remains a bit more flexible and holds well once it is very dry. Epoxy kinda scares me as it seems to set up too brittle.

I thought about reinforcing the balls by imbedding a bit of a steel needle through them. But the balls are so tiny that I do not have a drill small enough to core them out. And pushing a heated needle through them will surely destroy these tiny balls.

Inner Shaft Head Trim Mod
Author Email: J-MICHAEL at RC Universe
Specs: N/A
Material Required:
Downloads available:
Notes: You know how the flybar attaches to the top head, and clicks into place right ? You also see how its in there pretty tight to eh ? Well, I removed the top-screw and tossed it in the can, and even shaved a bit off the top head until it just about meets the top of the flybar top-piece... The MCX doesn't need it at all... I put a good 20 flights into her doing this, and all is fine... You'll see... Tracking stays good also. Its in there still tight as ever, since its braced into position anyway by the little locking stub and hole...

The benefit : A tad more energy that one motor gains as it now has less to crank-over... during the hard crashes, the flybar will usually unlock, and eject from the rotor-head assembly putting hopefully less stress then on the flybar, but mainly the weak inner-shaft that would take the blow the most during a crash from the upper-blades striking along with the flybar at the same time....

The disadvantages : ...shaving the top-portion of the head down some puts the flybar itself closer in relation to the ceiling, and makes it more interesting...
... Also... On your blade tracking for the uppers... Do the normal balancing and applying tiny pieces of tape if need be, but also try switching the flybar ball-link onto the otherside, and trying the other ball that you would attach it on the OTHER blade... Mine was off quite a bit a few times before... I switched sides, and then perfect tracking...

Inner Shaft Mod
Author: Bill Glover
Author Email: Bill Glover at RCGroups
Specs: N/A
Material Required: Dremel, paper
Downloads available:
Notes: Well my inner shaft was rubbing on the battery holder with one of my packs fitted (obviously fractionally fatter than the others). Rather than trimming the cross bar on the battery holder I'm going to Dremel off the surplus bit of the shaft.

Linkage Adjustments 2
Author: Metieval
Author Email: Metieval at RCGroups
Specs: N/A
Material Required:
Downloads available:
Notes: FROM FACTORY Because the horn on linear servo is already 2/3 of the way down. We get less travel pulling the swash down for forward flight. Because of the max travel distance on servo.

AFTER SHORTENING LINKAGE ROD When shortening the linkage rod it pulls the swash at a downward angle. Yes this causes forward flight. But now we add trim to re-balance the swash. This now puts the swash plate LEVEL for hands off hovering, and allows for equal travel front , or rear.

If you do shorten linkage rod "turn it a full 360 degrees" the linkage only fits onto the ball one way. This method works for those that have more rear travel than front travel. If you already have equal travel, try one of the other mods instead.

Linkage adjusments
Author: grnbrg
Author Email: grnbrg at RCGroups
Specs: N/A
Material Required:
Downloads available:
Notes: The servo rod lengths control where the range of swash movement is centered. This means that by adjusting the rod length, you can increase performance in one direction at the cost of the other. Out of the box, my mCX had fairly balanced performance front and back, but I wanted more speed, so I took the right ball link off and gave it 5 or 6 full turns. I then needed to add in a significant amount of back trim to get a stable, hands-off hover. However, my forward flight is now much faster than it was OotB, backward somewhat slower.

Changing the left link will similarly allow you to increase flight speed to the left or right, but only at the expense of the other direction.

Changing the flybar length or weight will improve the response speed, so you'll be able to change directions faster, but I don't think it will have a significant effect on total speed. And of course, the tradeoff for increased responsiveness is reduced stability.

Paddle Mod
Author: superdave42
Author Email: superdave42 at RCGroups
Specs: N/A
Material Required: Cutters
Downloads available:
Notes: I just cut the paddles in half. NOTE: Paddles are on backwards in the photos.

Pitch Rod Mod
Author: av8rOC
Author Email: av8rOC at RCGroups
Specs: N/A
Material Required:
Downloads available:
Notes: I found that by shortening the pitch linkage rod one full turn the Forward Flight (FF) was much improved. I can get it going both fwd and backward rather quickly now with no problems. No need to mod the flybar IMO

Simple Fast Flight Mod2
Author: MarioIArguello
Author Email: MarioIArguello at RCGroups
Specs: N/A
Material Required: N/A
Downloads available:
Notes: You can achieve fast FF or RF by simply sliding the battery forward or rearward without modifying or possibly destroying the swashplate (SP) arms in cutting and pasting them to make them shorter. In this manner, you use the standard cyclic control, to calibrate the flight attitude and let the weight of the battery do the FFF or FRF for you. You still have total control and it will feel great! give it a shot.

Simple Flight Mod
Author: Kilo60
Author Email: Kilo60 at RCGroups
Specs: N/A
Material Required:
Downloads available:
Notes: BY far the best fix for FFF (Forward Flight) is removing the right ball link from the swash plate and giving the servo rod ball link 2 full 360 degree turns....

Much faster FF and due to the fact that it makes the elevator control throws greater/higher, Rearward flight doesn't suffer much at all...

It's so simple and there is nothing to it...

Speed Up Mod
Author: RFpro
Author Email: RFpro at RCGroups
Specs: N/A
Material Required:
Downloads available:
Notes: This mod really can be done in 10 minutes at no cost. It is very effective and
reliable. IMHO: a must.

In contrast to the mod Sasha26 did, I used longer screws. For the details
please refer to the picture.

The small screws come with every spare blades. The small holes (diameter
0.8mm) should be drilled into the swash directly opposite to each other, not
to close to its upper edge.

The extension of the guide for the blade linkage can be realized by sliding
some extended insulating sleeve (ID appr. 1.2mm) over it.

Some screw heads are slightly to small for a tight fit of the linkage. Dipping
them into paint or some epoxy material solves the problem.

Modifying the flybar (shorter/lighter) will further improve the mobility.

Swash Plate Mod
Author: Okinchi
Author Email: Okinchi at RCGroups
Specs: N/A
Material Required:
Downloads available:
Notes: 1) Unscrew the tiny 2 screws on the lower drive gear (1~2 turns should be enough), to remove the upper blade.
2) Remove the linkage between the swash plate the lower blade, on the blade side only. Remove the tiny screws holding the blade to the shaft, now you can remove the lower blade.
3) Unhook the linkage from the swash plate, remove the swash plate.


Unfortunately, I did not take any picture during the modification. I hope, the drawing and the pictures of the swash plate in the heli will clarify what I mean.
I cut the arm in the middle of the part going straight out of the swash plate, and removed using sand paper (on the flat surface-my desk), from both ends, about 1/10 –th of an inch in total. (I think, it was a bit more, about 3 mm in my case). The original arm, measured from the ball to the other side of the swash plate, measures abount 1 inch, I measured 25.4 mm.
I glued carefully the arms back to the swash plate one by one, using first a bit of CA glue to fixate the shortened arms. I then, applied epoxy from each side to make the arms strong again. There is plenty of space on both sides to do that. The only thing you have to be careful about is not to glue the 2 plates of the swash plate together…
The modified arm is now 0.88 inch (22.4 mm) measured the same way.

It took me about an hour, and I made the first test. The heli moved fast to the back, and it required a mechanical adjustment on the linkage to the swash plate, as it did not move forward enough
The electronic trimming was not enough. Check, by pushing the go ‘forward stick’ on the transmitter, which linkage you need to adjust. Disconnect it from the swash plate, I needed to shorten it by about 6 full turns (clock wise, and .... there is a thread on the tiny links… yeah!).
The heli flies now about 3 times as fast forwards as before, it is faster going backwards and sidewards too.