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130X Blade 130X Helicopters Information and Help

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Old 03-26-2013, 11:15 PM   #1 (permalink)
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Default How do you adjust gear mesh?


Can it be adjusted? What am i looking for?

Last edited by Bodge; 03-27-2013 at 08:36 AM..
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Old 03-27-2013, 09:44 AM   #2 (permalink)
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Old 03-27-2013, 10:14 AM   #3 (permalink)
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I adjusted mine by loosening and pulling the tail out slightly so there was no back and forth play in the tt. It reduced the slight vibration I was having at the time.
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Old 03-27-2013, 12:17 PM   #4 (permalink)
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Default Gear mesh

Here are my opinions based on my recent teardown & rebuild of an initial model 130x that is on at least it's third owner. I apologize for the length, but find it a complex matter.

You want to strive for a sweet spot between things being too tight and too loose. Too tight and things will bind, grind, and lead to bearing wear. Too loose and things will rattle around (leading to vibrations) and maybe lead to chipped gear teeth (like on the metal A-gear that arrived on my used heli).

Fine tune things by looking at the gear mesh and, preferrably without the motor engaged, feeling things as the main shaft is rotated. In looking at things, edges on the teeth of mating gears would idealy line up (ie, forward edge of B-gear lines up with inside edge of the teeth on A-gear, outside corner of C-gear should line up with outside corner of D-gear. In feeling things, you want the main shaft rotation to be as smooth as possible. Any notchiness to the rotation means something isn't optimal.

There are many variables involved, and no setup is going to be exactly same because of manufacturing tolerances, use of aftermarket parts (which likely have their own tolerances on top of the OEM part they copied), installation methods, wear, etc. The parts we're using here aren't exactly made with swiss watch precision, so a certain amount of flex in the drive train is likely necessary. For example, in my case, the new Xtreme A-gear isn't perfectly round when it rotates, and every Blade C-gear I've tried has had a bit of angular tilt to it.

1) I started with the main shaft. Any vertical play in the main shaft will change how the A-gear meshes with the B-gear. In my combination of OEM and after market parts, I found I needed to add 4 of the Lynx main shaft shims to eliminate the vertical play. That's quite a bit. I then had to figure out whether the shims should go between the collar and upper bearing, or between the upper bearing and the A-gear. Putting them above the bearing will raise the A-gear, disengaging it slightly with the B-gear. Putting them below the bearing will push the A-gear down onto the B-gear. Experimentation with how the A-gear and B-gear mesh with the main shaft and torque tube components in an empty frame led me to thinking my best approach was to put all the shims above the bearing.

2) Then I looked at lateral movement of the B-gear (which I replaced with an Xtreme gear). It seemed to me that there's more movement allowed on the B-gear than there should be. In my teardown, I could actually see where the B-gear had pushed back and was rubbing against the frame. Regardless of what I ended up doing at the tail end or to fasten the B-gear to the torque tube, I wanted to prevent the B-gear from rubbing against the frame. I did this by using one of the small washers from the Blade 130x feathering spindle kit as a shim behind the B-gear. I used blue threadlocker to hold the B-gear on the torque tube, but I'll come back to that. I noted that the Xtreme A-gear has a slightly smaller diameter than the metal gear (HH I assume, but I don't know) it replaced. This is part of the reason why I felt I should add a shim to the B-gear.

3) I wanted to minimize end-to-end play in the torque tube. With the B-gear now shimmed and riding on the forward torque tube bearing, I felt the C-gear should be fairly snug against the bearing in the tail case, with the tail case placed on the tail boom so the torque tube stuck through the C-gear but still cleared the spacer on the tail shaft. Regardless, make sure the tail case isn't fully seated on the tail boom, or the end of the tail boom may be rubbing against the inner race of the aft torque tube bearing. I noticed that can happen with my RKH tail case. EDIT: In a later repair, I left just a bit of end-to-end play in the TT.

4) I then wanted to minimize end-to-end play in the tail shaft while optimizing how the C-gear and D-gear teeth appeared to mesh. Experimentation led me to adding a Lynx main shaft shim to the flange bearing by the D-gear (another perfect fit for a part intended for another application). EDIT: In a later repair, I found sanding down the nub on the C-gear just a bit further improved on this.

This gives me zero play throughout the tail drive, but I wouldn't say it's perfect. I now sort of wished I had not bonded the B-gear to the torque tube. That's really the only place to leave a little tolerance in the system, since the A-gear is tight to the main shaft, and both C and D gears are essentially tight fits on their respective shafts. Leaving the B-gear free would allow the B-gear to shift a bit as the out of round A-gear rotates, and allow the torque tube to shift in and out just a bit as the imperfect C-gear wobbles in it's rotation.

EDIT: With the newly added bit of play in the TT and the nub sanded on the C-gear, things are now pretty much as good as they can probably get.

Good luck!

Last edited by helibus; 04-10-2013 at 03:43 AM.. Reason: Clarifications and further improvements
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Old 03-27-2013, 01:22 PM   #5 (permalink)
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Gear lash at the A & B gear can be adjusted by using shims above and/or below the upper main bearing (between the main shaft collar and bearing, or between the A gear and main shaft bearing). This will move the A gear up or down to get the right lash between A & B. The shims are from Lynx. I haven't tried the shims yet, even though my main shaft does have about 0.3 mm up/down movement. The lash between C & D is pretty much fixed.

I let everything float and I have seen no wear on any of my gears after 80+ flights (using metal A gear supplied from HH). The original plastic A gear only lasted a few dozen flights.

EDIT: If you're talking about main gear/pinion mesh, it's not adjustable unless you do a mod to elongate the motor mount screw holes.

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Last edited by Smok1n; 03-27-2013 at 01:24 PM.. Reason: edit
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Old 03-27-2013, 03:04 PM   #6 (permalink)
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A-B mesh is set with the shims from Lynx. I have 3 shims on the top of the top main bearing (between bearing and main shaft collar).

C-D mesh is set with moving the boom in or out of the frame so the TT is not pushing C into D.

Good way to check gear mesh is to pull the main gear down a little so it is not touching the motor pinion, and not dragging on the bottom of the frame.

If your mesh is good but still have drag, check the tail shaft retaining collar, and back it out .1mm
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Old 03-29-2013, 04:14 PM   #7 (permalink)
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Cheers gents. Been having a play and i think ive got it all dialed in
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Old 03-29-2013, 05:38 PM   #8 (permalink)
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Outstanding post. SOME of us go into great detail to make thing as clear as we can. Kudos for that. I too have gone through many hours on the work bench getting my gear mesh perfect. Even gone as far as cutting a metal shaft colar and standing it down to fit perfectly to remove the vertical play in the main shaft while making my mesh between A &B perfect. My B gear is loctite 'd to my T.T so there is very very little horizontal play that has been adjusted by the amount of Boom that is backed off in the frame which leaves the perfect amount of shaft holding the C gear in place. Gear mesh is a big key when your using battery power to be your fuel for flight time. The smoother it is the longer your flight time. Same goes for all parts moved by servos. Keep things moving freely. less amp draw means more flight time. Enough said .
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Old 03-29-2013, 06:02 PM   #9 (permalink)
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from another thread:
i machined the "A" gear to the point it's considerably more concentric (true) than from the factory. you can probably use a drill motor with a tight chuck. this allows additional space if needed to shim the "B" gear and a constant mesh throughout the entire circumference. i shim the "A" gears so that pushing AND pulling with considerable force does not change the mesh. the result is dramatic. this may require shimming on multiple surfaces and possibly splitting the frame to achieve. test all your changes without the blades.

yeah,,, lynx for "A" gear.
feathering shaft shims for "B":... the msrx ones are just a tad too small and need very little material removed to work sweet. they r they same OD as the "B" gear shoulder and will not interfere with the bearing and or frame . at first i messed around with a bunch of other stuff.
get the "A" gear solid and smooth and you can run the "B" gear looser (float) without the risk of the gears pushing apart and stripping. if your "A" gear has to be turned down a little more, then you will need to shim "B" for sure.

the mesh up front will effect how well the copter will run.... from the TT to the tail resonating.

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