MSR - How I went from having massive TBE to rock solid stable

[Thewyzardofdogz]

There were times when my MSR flew so erratically and wandered around so much I didn't even want to fly it anymore. And now it's as solid as a rock and that's because I don't have any loose AND binding parts anymore. If you really want your TBE to go away forever you might need to spend some money but definitely do something with that useless stock flybar. Get this - I bought a BNF yesterday that flies really great out of the box but my 3 month old RTF never ever flew anywhere close to that good until I fixed it (and now it's better than new). A few of the stock plastic MSR parts are designed to wear and break. There is too much play (or not enough) in the case of the flybar and that's no good.

If you want to eliminate your TBE for once and for all do this:

1) Microheli makes a fairly expensive carbon fiber/aluminum flybar that I'm willing to bet doesn't work as well as this mod. You need to fix that poorly designed stock flybar that's constantly hitting the main shaft as it rotates - bore a 13/64" hole through it and take the steel ball from a plastic swashplate and slide it down the shaft so it is centered on the flybar. If you are willing to do this mod you will probably have eliminated your TBE and guaranteed made your MSR 2-3 times more responsive - you can stop on a dime. There's just not enough travel in the stock flybar and because it makes constant random contact with the main shaft the result is lost stability. But the flybar has so much movement now that at rest it will lay down on the canopy - won't it hit the canopy when it's spinning? Nope. No matter how aggressive you fly it, the new flybar will never make contact with the canopy - it's impossible. But the EQMOD thread says that the steel ball is not completely spherical and that it is better to use a brass ball with o-rings that dampen the travel. Well, that's true. The steel ball is not completely spherical but it does not need to be. Sure, at rest it looks like it could hit the main shaft but when the rotors are spinning it will never hit the main shaft because the hole is so much bigger than stock and it's got a nice smooth steel ball to rotate around. The only way it could possibly go past the ends of the steel ball is if it hit the canopy (which is impossible while it's spinning). Furthermore, if you use the brass ball with o-rings you are adding a lot of friction. The steel ball is way smoother (less friction, what you want). There is no need for o-rings above and below the ball to dampen the flybar movement because during flight the flybar can not travel that far. This was the biggest single improvement in stability that I noticed.

2) Get rid of those silly plastic parts and make your helicopter tight. Do you know why your helicopter comes with that red swashplate tool? Because they made the plastic swashplate so that part of it (the steel ball) is very snug against the main shaft (because it has an o-ring on the inside of it) and the rest of it just pops apart because there is no give. Once that ball starts getting loose in the outer bearing race, you get slop. A brand new plastic swashplate has quite a bit of bearing slop already. A brand new microheli swash has zero bearing slop and the inner ball is allowed to slide freely up and down the shaft. Because of these two features I don't see how it could ever come apart the like stock swash and I can't see ever having to use that red tool again. Another advantage is the aluminum vs. plastic balls on the swash. Though I've never broken a plastic ball off, the aluminum is definitely going to be stronger. It might not survive a crash into the pavement - so don't crash it into the pavement and you should be all right. I also got the microheli anti-rotation collar and the rotor head. These parts are so much tighter than the stock plastic parts. Some people swear by the plastic parts but I consider them to all be very sloppy when I compare them to the microheli parts. The microheli parts contain no imperfections as they are cut by a computer-guided, laser-guided water jet, not stamped into moulds.

3) Make sure that tail boom is secure. If it ever moves or vibrates or the tail fin vibrates that can send incorrect data to the gyro which will in turn tell the computer to make false adjustments to the servos which will reduce stability. I put a drop of hot glue where the boom connects to the main frame and I also hot glued the tail fin (on the side with the two clips) so there is zero movement there.

4) Make sure there is no up and down play in the main shaft (and that the shaft is not cracked).

5) Make sure (take them off and look at them) your servo arms are not bent and that the servos are tight to the board.

6) How old is your MSR? Get a new tail boom and a new main motor.

7) Make sure your main blades are not bent and that they are tracking properly. The blades should be perfectly straight (touch from end to end on a glass table). If they are not straight and don't track properly your heli will vibrate. If your heli is vibrating the gyro is receiving incorrect information and is trying to compensate for it.

So basically if you fix your flybar, get rid of all the slop associated with the plastic rotor parts and make sure your tail boom is secure, your heli will not have TBE I guarantee it. There's no such thing as 100% TBE free but 95%-98% free is definitely possible. A note about the new hole in the flybar. It may be slightly noisy (screechy) for the first little bit until that steel ball has a chance to polish it nice and smooth.

[Thunder]

Sounds like a good mod. Do you have any video?

[Thewyzardofdogz]

I haven't made a video yet but I am definitely going to this weekend because my 2 MSR's just fly so good.

[dacaur]

some pics of the flybar mod would be cool