Yet another burst tail bearing

[Tachead]

Another thing too is when you tighten the tail case sides, you have to be careful how you do it. I found that if I just tightened them, due to the slight play between the screws and plate holes you could make the bearings side load slightly. I was able to correct this by pressing the tail case down on a perfectly flat surface, keeping the side plates perfectly aligned, and not letting it move as I tightened the sides. The main thing is that when the side plates are tight, you need to spin the tail shaft and check for bearing side load or notchiness. The tail shaft should run butter smooth. If it doesn't you need to re-tighten the tail case sides until you get it smooth or it will wear the bearings faster

[Luigi_tuga]

Originally Posted by Tachead

Another thing too is when you tighten the tail case sides, you have to be careful how you do it. I found that if I just tightened them, due to the slight play between the screws and plate holes you could make the bearings side load slightly. I was able to correct this by pressing the tail case down on a perfectly flat surface, keeping the side plates perfectly aligned, and not letting it move as I tightened the sides. The main thing is that when the side plates are tight, you need to spin the tail shaft and check for bearing side load or notchiness. The tail shaft should run butter smooth. If it doesn't you need to re-tighten the tail case sides until you get it smooth or it will wear the bearings faster

+1

The check for free spin should be done with belt off, to feel the bearings without interference.

It crossed my mind that when i built my Warp, i used a file to carefully grind a bit of plastic from the lip in the shaft pulley, to get that perfect and free spin.
Without doing this very slight grind, it was'nt bad but not perfect.
I like to give the shaft a good spin (only the shaft) with the finger tips, and see the shaft performing several revolutions. Then it's free and good to go.

[birchbore]

I don't think it hurts to get a bearing buddy and make sure theres grease in them, my latest warp build I greased every single bearing and a few had almost nothing in them

[fjoe]

Can you post a link to the bearing buddy that works on these small bearings?

[birchbore]

I cant but you could search it and find it, its on the freak somewhere

[Tachead]

Originally Posted by birchbore

I don't think it hurts to get a bearing buddy and make sure theres grease in them, my latest warp build I greased every single bearing and a few had almost nothing in them

Grease is not the best option in a non-sealed bearing that is turning 10000rpm plus. The best way to lubricate a bearing like this is how I stated earlier in the post. Oil them every 5 flights or so with a drop or two of high speed bearing oil like Scorpion motor bearing oil or Trinity bearing oil

[birchbore]

I grease them, spin them on a drill to remove excess, works good for me,last longer. also fjoe, use washers with small holes for small bearings with buddy if you get one

[Tachead]

Originally Posted by birchbore

I grease them, spin them on a drill to remove excess, works good for me,last longer. also fjoe, use washers with small holes for small bearings with buddy if you get one

You have to take them out to do that though and the grease will not lubricate very long as it is thrown out as the stock bearings are only shielded and not sealed. Grease is not ideal for this purpose. Trust me on this one, it is a proven theory. The tail bearings are turning at over 15000rpm with the 17 tooth tail pulley and 3200rpm head speed. Oil is the way to go on a high speed shielded bearing unless you want to take apart the tail and grease constantly Grease is best suited to low speed sealed bearings.

[birchbore]

Originally Posted by Tachead

You have to take them out to do that though and the grease will not lubricate very long as it is thrown out as the stock bearings are only shielded and not sealed. Grease is not ideal for this purpose. Trust me on this one, it is a proven theory. The tail bearings are turning at over 15000rpm with the 17 tooth tail pulley and 3200rpm head speed. Oil is the way to go on a high speed shielded bearing unless you want to take apart the tail and grease constantly Grease is best suited to low speed sealed bearings.

I understand the theory, i hear what your saying. i fly all year and disassemble in the winter to check or replace my bearings and there is still grease in my bearings. works for me

[crf69]

throw some abec5 in the tail and be done with it

[Tachead]

Originally Posted by birchbore

I understand the theory, i hear what your saying. i fly all year and disassemble in the winter to check or replace my bearings and there is still grease in my bearings. works for me

The grease gets thrown to the sides of the bearing and is no longer lubricating after a while. The excess comes out as you probably see it oozing out the sides at first. You still find it in there as it is stuck in the cup of the back of the metal shields and is no longer doing anything. There is a reason high speed shielded bearings in almost all applications, even others then RC, call for oil. If you swap the bearings for non-contact sealed bearings then the grease will stay in from the factory and you don't need any grease. It's your heli and you can do as you please but, understand that you are not going to see the same service life unless you grease the bearings often or oil regularily.

Sent from my SGH-I337M using Tapatalk

[Tachead]

Originally Posted by crf69

throw some abec5 in the tail and be done with it

For sure, I think I am going to order a nice set of Bocas for it.

Sent from my SGH-I337M using Tapatalk

[velocity90]

High abecs are nonsense in helis. The possible cause i explained earlier. Safe your money and loctite the shaft with blue. It explodes due overheating

[crf69]

for the warp tail....its absolutely necessary. ask me how i know!!

Sent from my Samsung S4 using Tapatalk 4 because Tapatalk2 just vanished........

[velocity90]

[ARM_Coder]

Well, I tested my Warp last weekend and it flew like a champ. No burst bearings or any other issues.

The repair I made - while waiting the new parts to arrive - became quite ugly, but fully functional. I think the key here was to secure the shaft against the inner bearing races with a tiny drop of 242 threadlock. And apply a good deal of lube into the bearings.

The most impressive here is how the tail pulley shows signs of melting at the side of the bearing that failed in the last incident. Fortunately the pulley hasn't become warped with the excess heat.

Can't wait the new parts to arrive so my Warp can get back its nice look...

Cheers!

[Jeff_Barrett]

Do yourself a favour and use both metal tail side plates. It will save you a lot of grief in the future.

There's a reason Compass released and ships only the metal side plates now.

[Tachead]

Originally Posted by ARM_Coder

Well, I tested my Warp last weekend and it flew like a champ. No burst bearings or any other issues.

The repair I made - while waiting the new parts to arrive - became quite ugly, but fully functional. I think the key here was to secure the shaft against the inner bearing races with a tiny drop of 242 threadlock. And apply a good deal of lube into the bearings.

The most impressive here is how the tail pulley shows signs of melting at the side of the bearing that failed in the last incident. Fortunately the pulley hasn't become warped with the excess heat.

Can't wait the new parts to arrive so my Warp can get back its nice look...

Cheers!

Nice, its a Hybrid Warp tail

[ARM_Coder]

Replacements are already on their way, this is really to be a short-lived solution. I won't wait it to fail before fixing it the right way.

Cheers!

Enviado de meu GT-I9300 usando Tapatalk

[lowey79]

Originally Posted by Tachead

Another thing too is when you tighten the tail case sides, you have to be careful how you do it. I found that if I just tightened them, due to the slight play between the screws and plate holes you could make the bearings side load slightly. I was able to correct this by pressing the tail case down on a perfectly flat surface, keeping the side plates perfectly aligned, and not letting it move as I tightened the sides. The main thing is that when the side plates are tight, you need to spin the tail shaft and check for bearing side load or notchiness. The tail shaft should run butter smooth. If it doesn't you need to re-tighten the tail case sides until you get it smooth or it will wear the bearings faster

Another thing to check for is that the side plates are parallel to each other when mounted To the tail block. Otherwise the bearings will not run true. I carefully filed the tail block to true up the side plates, and then shaved the shoulders on the pulley down to fit perfectly between the bearings.