x400 Front Shaft, Gear and Pulley set

[fedex]

I'm running x400 cf ccpm frame with align 3550kv motor 12T pinion 325mm blades, all trex head. Not sure what the blade rpm is but I run the motor at a flat 85 - 90% to 100%. I wonder about the x400 Front Shaft, Gear and Pulley Set, could this be a problem, its still stock, and the bearings are old. Has anyone stripped any of these in flight?

Heli wasn't flying like it should today so I ordered the precision front shaft gear n pulley set along with metal blocks for the main and front shaft. The parts come with new bearings, so I figured what the hey, 65$ is what it cost me after buying a few extra screws. My heli makes a ticking noise when I spin it by hand, for every revolution it makes, and I'd like to solve this problem. Bearings in tail casing look ok
...
After flying a bit more, Btw did my first piros inverted today... YEAH BABY!! I really had to set my mind to it. After the second one I came across a roaring sound. I landed right away, noticed the x400 metal tail casing was coming apart. It was seperating in flight, the belt pully was extremely loose all the sudden, and all the screws were backing out. You can bet I'll be going over it with loctite tonight

I think that this was the problem the whole time, everything seemed tight. But in fact it wasn't. After spinning the rotor by hand I hear no noise anymore, and spins freely as Finless Bob's trex!

[fedex]

ell the next day came to fly, I had the belt kinda tight, but no problem, the tail casing bolts were snug. I put threadlocker on them the day before. I took er out did some inverted piro pushes, I guess you can call em that. Anyway, I heard anothering roaring sound like when the tail casing bolts came loose.. This one was different, it was the one holding the tail fin in place, and the tailcasing to the tube. It broke right in the center of the bolt (about where the threads start). DAMNIT gime a break here.. Looks like I'll be working at trying to get the bolt out. It may need a new tail casing by the time I'm through, must be vibration from the stock front shaft drive gear and pully. Still waiting on my replacement. But I may need more than that:/

Well, operation complete, salvaged the tail casing this time. I had to drill it out and put a long bolt through it with a nut. Lets see what else works loose on this tail :/

Seems the speed I'm pushing with the 430L might be a little much for the aluminum mx400 pro tail. I still hear some kind of ticking inside the tail. All bearings look ok, I'll have to have a new tail before long.

[Gizmo6035]

If blue loctite isnt holding try cleaning the parts with acetone of laquer thinner before assembly.
Check the whole bird for vibes and eliminate all you can, if things keep coming loose use red loctite on the problem areas but you will need to use heat to take them back apart at next service/ repalcement.

I haven't started shaking the screws loose but I was on the third set of tail bearings and second set of side plates, neither item is cheap to be replacing.
I finally gave in and put the T-rex tail assembly on to include the new tail rotor and metal pitch plate set. Big difference, smoother operation, more rudder authority, and reasonably priced replacement prices for bearings and shafts, and the piro rate is scary, cant count the revolutions its so fast.

[fedex]

Originally Posted by Gizmo6035

If blue loctite isnt holding try cleaning the parts with acetone of laquer thinner before assembly.
Check the whole bird for vibes and eliminate all you can, if things keep coming loose use red loctite on the problem areas but you will need to use heat to take them back apart at next service/ repalcement.

I haven't started shaking the screws loose but I was on the third set of tail bearings and second set of side plates, neither item is cheap to be replacing.
I finally gave in and put the T-rex tail assembly on to include the new tail rotor and metal pitch plate set. Big difference, smoother operation, more rudder authority, and reasonably priced replacement prices for bearings and shafts, and the piro rate is scary, cant count the revolutions its so fast.

yeah, I don't think it was made for this kind of rpm from the 430L, I sure hope they changed the design from the x400 to the 450 tail assembly. I never started having problems until I started bumping my headspeed up to 85 - 90 %. I think some vibration could be coming from the front counter drive gear. Should have my replacements today, however I hate fixing a bird that will fly as is, I may wait until I have another problem. Just hope it isn't too late. I like my piro rate slow for now
I've been thinking about the upgraded tail. I guess the align is the one to buy? or did you get the microheli upgrade? Did you get the one with plastic casing? It will prolly take one more problem with the tail before I replace it. All I need is one good reason

[Gizmo6035]

No plastic parts here I am more concerned with strength and durability, these are the parts I used.
http://www.grandrc.com/inc/sdetail/24969
http://www.grandrc.com/inc/sdetail/49346

[CRJ]

Hey Fedex,

I had the same problem with my new mx450 right out of the box. The tail case was loose on the carbon fiber tail shaft so I tried tightening the case screws and the upper one broke! Just about the same place you described it by the threads. Anyways being a new bird, I sent that part back for replacement. Still waiting, It should be here today. I'm gonna try some dubro socket head screws for the case screws when I put it back on (no more Japan standard phillips head!)

Mike

[fedex]

Originally Posted by CRJ

Hey Fedex,

I had the same problem with my new mx450 right out of the box. The tail case was loose on the carbon fiber tail shaft so I tried tightening the case screws and the upper one broke! Just about the same place you described it by the threads. Anyways being a new bird, I sent that part back for replacement. Still waiting, It should be here today. I'm gonna try some dubro socket head screws for the case screws when I put it back on (no more Japan standard phillips head!)

Mike

yeah those screws just suck. Then they charge you over a buck for 4 of them. Its kind of ridiculous if you think about it.

Gizmo: nice deal on the tail casing, I have the matching trex head for it


Btw guys, I spun it up today and the other bolt just broke right before I switched to idle up.. Around 70% throttle. So I ordered those parts Gizmo listed. Seems like a pretty good deal. I spent extra on the overnight shipping, but I need this! Precision front shaft and pully, along with blocks and bearings should be here tomorrow as well. DAP!
Don't think I'll be drilling out this bolt. I'll end up selling it for cheap, or more than likely chunking it because its not worthy! All I can say is they should change the design on the 450. Even though I probably have a slight front shaft wobble which is causing these bolts to break, they still shouldn't break. Anyway.. all will be changed soon enough

[fedex]

Front shaft installation was a success, I'm impressed with the quality. Its micro heli's x400 shaft front gear shaft and pulley, seems real straight compared to the stock. The mesh is tight. But should work back loose, or at least I hope. New bearing blocks have been added along with the bearings, both front and main. I should have my new tail assembly tomorrow. I noticed my belt is frayed just a little on the edge where the edge of the tail casing pully was rubbing it, this i hope will be ok

Man this thing is almost 95% trex se after the tail assembly gets here

[Gizmo6035]

I noticed my belt is frayed just a little on the edge where the edge of the tail casing pulley was rubbing it, this i hope will be ok

I would keep a close eye on it, take note of which side the belt wants to ride and put the fray towards the opposite side.
Next order get another Helimax long belt for a spare, they cost more but don't seem to wear as fast as the Align belts.

I'm impressed with the quality. Its micro heli's x400 shaft front gear shaft and pulley, seems real straight compared to the stock.

I cheat, I use the Microheli front gear on the Helimax stock shaft and gear, nice and smooth on top but still have a little wobble on the plastic gear,
Don't waste your money on the Microheli rear gear and hardened shaft with the Align tail assembly, it is too long and causes pitch plate links to bind. I had to grind a flat closer to the hub to eliminate the over travel. When this shaft needs replacement I will use the newer Align metal pully and shaft whick look much better up close than on Grand's web site.

[fedex]

Well I get the rest of my parts today, Almost couldn't figure the linkage out, but man it works now. Smooth as silk, looks like you can swing alot more pitch into the blades, I may have to drop the limit until I get used to it. Haha, this is going to be cool. Only wish I told the guy to include a gray tail blade grips, the blue ones just don't look as good on this bird. I was sticking to gray and red

I'll probably never upgrade spindles or main shafts, I'd rather them bend in the event of a crash. shafts are easy to replace. Its the grips and everything else I don't want to replace.

Next thing is to get these stock fins off. I'm making the vertical out of cf, should be pretty cool. I tried a razor but it was impossible. Nothing the dremel can't handle.

Backwards flight should be easy with this tail setup using the Gy401 - 9650, but the winds would be blowing 25 mph after the setup. Isn't that how it always works out?

[Gizmo6035]

Next thing is to get these stock fins off. I'm making the vertical out of cf, should be pretty cool. I tried a razor but it was impossible. Nothing the dremel can't handle.

jig saw, band saw, or hack saw and a file are safer options than high speed tooling on carbon fiber. What ever you decide to use wear a respirator or good quality dust mask, long sleves, and work out side if possible.
Graphite aka Carbon Fiber is not known to be a carcinogen (yet) but it is an irritant and the less you ingest the better off you will be, but it sure does make some nice fins.

[fedex]

Originally Posted by Gizmo6035

jig saw, band saw, or hack saw and a file are safer options than high speed tooling on carbon fiber. What ever you decide to use wear a respirator or good quality dust mask, long sleves, and work out side if possible.
Graphite aka Carbon Fiber is not known to be a carcinogen (yet) but it is an irritant and the less you ingest the better off you will be, but it sure does make some nice fins.

I wore some gloves, and dust mask, with a fan blowing out the window 3 foot away. I got the outside pattern cut, but I gave up on it as its just too messy. I may use a drill / wood bit for medium to large holes in the center to cut down on the weight, for now I'll be using the x400 fins.