Extra bearing on Torque Tube--Trex 450L

[cobieg]

Originally Posted by weav01

May I ask where you bought the extra TT bearings? I only own one and think that another or two in the tail might help. Sure can't hurt!


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Helidirect

[weav01]

Originally Posted by cobieg

Helidirect

Thanks.


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[Crashtestheli]

I thought this was common knowledge - maybe not...

make sure the TT is straight - especially the ends.
make sure the gears on the ends have the TT "slots" in the middle.

take the main blades off
take the tail off.

put one bearing one in the stock location.
spool up the heli slowly without the tail on - watch the TT - Not full head speed - past 50% for sure

if it spins straight you are done.

add the second bearing one inch from tail end - spin up heli
move to 1.5" ...
move to 2" ...

use a felt tip marker to mark the TT tip and move the bearings until it spins straight
put the tail back on and go fly.
Each TT and gears will have different locations for the bearings

[Hemant T]

I had noticed by skids were wobbling so inspected my heli more closely and noticed the vibes are coming from the end of tail section … Have decided to put additional bearing for TT. Hope this will solve the problem coz there is no other place I can see the vibrations coming from.

I plan to keep one bearing at the stock location(as per manual) & other one mid position between the stock location & tail end… or you’ll advise keep it close to the tail end section?

[FrankFuss]

Check that there is not too much play in the tail shaft bearings. This can be a source of vibration, even if the tail is balanced well.

[Hemant T]

Guys, I'm in highly frustrated with the Dominator
Tried out all ticks and no success

Let me explain... Following items have been changes so far,
- Main Shaft
- Tail Shaft
- Feathering Shaft
- Additional Bearing added, One bearing added at the stock location & other one added 1inch to 2inch from the end of the tail hub.

After all these changes and trial’s, there has no changes in wobble. Please guys give a solution. I've noticed if i spool up the heli with no tail section there is no vibe and even after putting the tail hub without tail blades there is no vibes. As soon as I put the tail blades the Vibes are back... so changes the tail blades also still NO difference

...Pls Help!

[scooty]

Wow reading this thread I have the same issue with my 450L. I just built it and cant get it off the ground. Terrible vibration and wobbling. Will try the recommended fixes posted here and let everyone know how it goes. Thanks for all the tips.

[Hemant T]

Originally Posted by scooty

Wow reading this thread I have the same issue with my 450L. I just built it and cant get it off the ground. Terrible vibration and wobbling. Will try the recommended fixes posted here and let everyone know how it goes. Thanks for all the tips.

My problem still not sourted...
Have put two bearing also changed shafts but not improvement. Plan to change the TT and see now.

[Hemant T]

Originally Posted by Sefrez

Assuming good bearing placement, my guess is that these problems are not initiated by curved or mis-balanced torque tubes. It is probably the umbrella gear in the front gear box. I know the one I have installed is not perfect. Where the TT inserts, it is not aligned with the rotation of the gear. This causes the TT to flex in a direction with respect to the gear, and as it spins, so does the flex. Increase the RPM and then the flex is larger.

I try to back the TT out from the front umbrella gear as much as I can without making the rear one suffer. So about in the center of its back and forth freedom. I haven't had any problems yet with over 50 flights and a single bearing. Some umbrella gears are going to be worse than others though, and I may be lucky.

Definitely glue the bearing to the TT. Otherwise your just giving for another degree of freedom.



Put the bearing nearer the front by a few millimeters. It seems the front of the TT is worse off than the back.

Buddy I really need Help.

After all this experiment I’ve not been able to solve my vibration issue on 450L. I've changed main, feather, tail shafts along with TT and boom, also added one extra bearing. One is installed at the stock location and other one 1-2inch from the end of the tail.

But still not difference.

But I’ve realised a problem... when I spool the heli without Main & tail blades the vibes are not there, as soon as i put the tail blades on the vibes are back. Tried changing the tail blades still no difference. So i tried checking how the tail end gears are (Gears which are 90degrees to each other) & noticed they are not moving smooth... so you think that is what creating the vibrations?

[Hemant T]

Originally Posted by Sefrez

Assuming good bearing placement, my guess is that these problems are not initiated by curved or mis-balanced torque tubes. It is probably the umbrella gear in the front gear box. I know the one I have installed is not perfect. Where the TT inserts, it is not aligned with the rotation of the gear. This causes the TT to flex in a direction with respect to the gear, and as it spins, so does the flex. Increase the RPM and then the flex is larger.

I try to back the TT out from the front umbrella gear as much as I can without making the rear one suffer. So about in the center of its back and forth freedom. I haven't had any problems yet with over 50 flights and a single bearing. Some umbrella gears are going to be worse than others though, and I may be lucky.

Definitely glue the bearing to the TT. Otherwise your just giving for another degree of freedom.



Put the bearing nearer the front by a few millimeters. It seems the front of the TT is worse off than the back.

Buddy I really need Help.

After all this experiment I’ve not been able to solve my vibration issue on 450L. I've changed main, feather, tail shafts along with TT and boom, also added one extra bearing. One is installed at the stock location and other one 1-2inch from the end of the tail.

But still not difference

But I’ve realised a problem... when I spool the heli without Main & tail blades the vibes are not there, as soon as i put the tail blades on the vibes are back. Tried changing the tail blades still no difference. So i tried checking how the tail end gears are (Gears which are 90degrees to each other) & noticed they are not moving smooth... so you think that is what creating the vibrations?

[Luigi_tuga]

So, you may change those gears, they could be defective, or not properly set on the tt.
I don't have experience with tt, I'm a belt man, but it seems those gears could be the guilty parts.
You could also put a new boom, it may have a tiny bend and force the tt to spin off center.
Also a new tt if possible.
It's the best to try these parts once at a time to find that guilty part

[FrankFuss]

Originally Posted by Hemant T

But I’ve realised a problem... when I spool the heli without Main & tail blades the vibes are not there, as soon as i put the tail blades on the vibes are back.

Make sure you do not have play in your tail shaft bearings. Sloppy tail shaft bearing can cause vibrations even if the tail is balanced perfectly. I fixed such a tail vibration problem by replacing my tail shaft bearings with good bearings. I used ABEC-3 bearings from HeliDirect, but any quality bearing, like from Boca Bearings, would be a good choice.

[HawkySvk]

My vibrate too. Source is definitely tail drive assembly.Umbrella gears are out of round. I am disappointed. I expected better quality. Waiting for parts to change....

[CrashNburn420]

Make sure the tt gears are set correctly, it's easy to compress them together too tight. On the gear on the tail box, push the gear the tt goes in with you finger and thumb to make sure it's seated right. If it's to tight it will give you issues.

I have the 450dfc, for the front gears I can try pushing back the gear with a flat head screwdriver through the frame.

If the gears still to tight they could be messed up. Try new gears

[Hemant T]

Will try out all these tricks & get back to you'll.
Thanks for your suggestions guys!

[truckermusic]

Originally Posted by Hemant T

Will try out all these tricks & get back to you'll.
Thanks for your suggestions guys!

Herman
I don't have the 450L but I do have the 450 DFC Pro V2 which I have rebuilt so many times I have run out of fingers and toes....

Here are some of my suggestions if you will....
1. I have two bearings on my Torque Tube.
I mark my TT into thirds, on the 1st third that goes to the front Gears I put the bearing slightly off my mark and towards the center of the TT.
On the mark closeset to the tail I glue my bearing off set of my mark toward the center of the TT meaning away from the tail......
nothing in the middle.

2. Next I would very lightly spray Lube (with like a silacone spray that is nice to rubber) the inside of the Boom.

3. Oil the bearings very well...make sure they are BUTTER SMOOTH....if not replace......put some grease on the inside of the rubber bearing housing and make sure it is seated correctly around the bearing....This will keep the bearing lubed as it works....

4. carefully slide the TT into place into the boom...as you slide the TT slowly spin it inside the boom.....

now put the boom into the transmission case and seat the TT......( take your main blades and your tail completely off..) this way you can see the tail end of the TT sticking out of the back......

now very carefully spool up the heli....watch the tail end of the TT.....it should spin very smoothly and be as close as possible to being centered....if it does not then gently remove (pull) the TT and Rotate it to the right 1/4 turn....

Do the same proceedure....if it spins smoothly then put your tail case back on....if not then repeat until it does......One of the positions will spin smoother than the others so pick the smoothest one


5. Next, I would try to Balance the tail blades.... Just like you would the Main Blades...no different.....also try different style of blades.....this made all the difference for me......

Also take the tail blade grips apart and see if the thrust bearings need to be cleaned and greased / lubed

6. clean and lube the entire tail section (all the bearings) very carefully......what I am thinking here is that you may have a bad bearing some where in the tail case that needs to be replaced.....remeber a bearing should be butter smoooth...if not then replace it with fresh ones......that would cause you the vibration......

7. Next I would look at the TT Rear Gears.....the umbrella gear may need to slide BACK into the housing a tiny bit more...( I know cause mine had to be done last night).....just take a flat head screw driver and place it between the umbrella gear and the rear drive shaft and "CAREFULLY and GENTLY" twist the screwdriver.....you will feel the gear slide back ever so gentle.....all you need to do is put a little tiny space in there so it does not rub up against anything other than the transfrer gear....

8. lastly put a small dab of grease on the umbrella gear and spin the drive shaft.....it may smooth out any binding......


Hope these help
Clifford

[Hemant T]

Originally Posted by truckermusic

Herman
I don't have the 450L but I do have the 450 DFC Pro V2 which I have rebuilt so many times I have run out of fingers and toes....

Here are some of my suggestions if you will....
1. I have two bearings on my Torque Tube.
I mark my TT into thirds, on the 1st third that goes to the front Gears I put the bearing slightly off my mark and towards the center of the TT.
On the mark closeset to the tail I glue my bearing off set of my mark toward the center of the TT meaning away from the tail......
nothing in the middle.

2. Next I would very lightly spray Lube (with like a silacone spray that is nice to rubber) the inside of the Boom.

3. Oil the bearings very well...make sure they are BUTTER SMOOTH....if not replace......put some grease on the inside of the rubber bearing housing and make sure it is seated correctly around the bearing....This will keep the bearing lubed as it works....

4. carefully slide the TT into place into the boom...as you slide the TT slowly spin it inside the boom.....

now put the boom into the transmission case and seat the TT......( take your main blades and your tail completely off..) this way you can see the tail end of the TT sticking out of the back......

now very carefully spool up the heli....watch the tail end of the TT.....it should spin very smoothly and be as close as possible to being centered....if it does not then gently remove (pull) the TT and Rotate it to the right 1/4 turn....

Do the same proceedure....if it spins smoothly then put your tail case back on....if not then repeat until it does......One of the positions will spin smoother than the others so pick the smoothest one


5. Next, I would try to Balance the tail blades.... Just like you would the Main Blades...no different.....also try different style of blades.....this made all the difference for me......

Also take the tail blade grips apart and see if the thrust bearings need to be cleaned and greased / lubed

6. clean and lube the entire tail section (all the bearings) very carefully......what I am thinking here is that you may have a bad bearing some where in the tail case that needs to be replaced.....remeber a bearing should be butter smoooth...if not then replace it with fresh ones......that would cause you the vibration......

7. Next I would look at the TT Rear Gears.....the umbrella gear may need to slide BACK into the housing a tiny bit more...( I know cause mine had to be done last night).....just take a flat head screw driver and place it between the umbrella gear and the rear drive shaft and "CAREFULLY and GENTLY" twist the screwdriver.....you will feel the gear slide back ever so gentle.....all you need to do is put a little tiny space in there so it does not rub up against anything other than the transfrer gear....

8. lastly put a small dab of grease on the umbrella gear and spin the drive shaft.....it may smooth out any binding......


Hope these help
Clifford

Thanks Buddy ... Will try out each step and hope ths problem is resolved.
Coz i'm quite feedup and not happy how Align is loosing quality on their products.

[TRAXXAS6606]

Originally Posted by AlvaSpeed

I dont know if this have been posted before.

Today I was chasing an electrical problem with the esc and spooled up the heli (without blades of course) and felt a large vibration at high rpms.
Took the tail assy (boom-tail) out and spooled the heli again and it was vibration free.
Took the Torque Tube out and saw some scratches on it (rubbing against the boom).
Installed a new Boom and Torque Tube, (glued the bearing per Align instructions) spooled up and after a couple of seconds it started to vibrate again.
Took the new Toque Tube out and it was scratched in the same place as the older one.
I think the TT is too flexible.
So I went and installed an additional bearing on the torque tube on the same spot it got scratched and problem solved.
Check out the pics......

My brand new 450L has the same problem! And when I put it on flight mode 2, the vibe was so much that it made my Vbar go crazy and my new Heli banked hard to the right and into the dirt. I'm thinking that was the cause because I had bag tail vibes that I finally was getting out. I'll try that. Thanks!

[genuine]

Originally Posted by cobieg

I did not know you were supposed to "glue" the bearing. What glue is used for this?

never have I glued a ttb bearing in.you put oil on the rubber boot an push it in the boom. Its not gonna go anywhere.it lodges it self.

[Helique]

Originally Posted by genuine

never have I glued a ttb bearing in.you put oil on the rubber boot an push it in the boom. Its not gonna go anywhere.it lodges it self.

Instructions state to glue the bearing to the TT with a drop of thin CA. If you are not doing this, the TT could be spinning in the bearing’s inner race, causing vibrations.