Thrust bearings for tail rotor

[Mark A Smith]

Hello to all,I just received the upgrade kit for my 550.CNC main grips,head block,
lightweight f/bar paddles and thrust bearing tail grips.Well I thought i would look into one of the grips to see what GAUI had done compared to the stock 2 radial
bearing arrangment.To my suprise I found the thrust bearing at the hub side of the blade holder???:confused: Am I nuts or is this backwards to what it really should be???:shock:
I feel that the t/bearing should be on the blade side of the holder due to centrifuge
forces going outward toward the T/R blades?????? HELP!!!!!!!

Thanks
Mark Smith

[bugdozer]

Bob brought this up in one of his videos on the main blade grips. As long as the inner race on the outer bearing is resting against the thrust bearing, it should work fine. If the outer bearing is able to move in the blade grip, transitioning the lateral forces to the thrust bearing, this is actually a good design as the outer bearing is providing better support by being out further on the tail hub shaft.

[Sunkan]

I have bought those "upgrade" thrust tail grips too..

But since I don't have any problems yet I have not started using them.
I just bought them in case I get problems when I raise the headspeed.

But I noticed that there is a massive side to side play withe the thrust bearings compared to without.

Is this normal for thrust bearing tail grips?

[slo_dave]

I just received the new thrusted tail grips and am having problems..

Just received them today
I see two problems
(1) When screwing down to the hub, the grip binds/locks up against the hub at even hand tight
(2) When tightened down all the way the screw protrudes into the hole for the tail output shaft preventing the hub from even being able to be installed.

I'm installing these as shipped:
From blade side I have bearing/small OD race/thrust bearing/large OD race...although I reversed with same result.

Anyone else having same problem or ... no problem with new grips?

[Happy|Harry]

I just received the new thrusted tail grips and am having problems..

Just received them today
I see two problems
(1) When screwing down to the hub, the grip binds/locks up against the hub at even hand tight
(2) When tightened down all the way the screw protrudes into the hole for the tail output shaft preventing the hub from even being able to be installed.

I'm installing these as shipped:
From blade side I have bearing/small OD race/thrust bearing/large OD race...although I reversed with same result.

Anyone else having same problem or ... no problem with new grips?

try putting it on the tail shaft and then tightening down the grip screws :)

phil

[mjdee14]

HH is correct...put it on the shaft first...it's actuallu a good set up because you have 2 allens and the 2 bolts holding it on the shaft.....

Now if we could just figure out the vib problems..

[red_z06]

Here is the schematic (in words cause I'm lazy) of how thrust bearing unloads either outer or inner race of R-B.

A Config
1. Grip flange (the part that stops the outer inner most R-B near hub) applies axial load ( along the axis of the shaft )
2. Outer race of the R-B is pushed by the grip. That means inner bearng should not see the axial load.
3. washer is needed so outer race is contacting the T-B and clearance for inner race (free to slide back and forth)
4. washer contacts T-B and Outer race of R-B
5. T-B is installed
6. T-B is constrained by means of nut or bolt with any size washer.
(inner race is not loaded axially)

B. Config
1. Grip applies axial load
2. T-B is pushed by the grip
3. washer is needed so T-B transfers axial load to ONLY inner race
4. washer of same ID as the shaft and small OD so it never contacts the outer race of R-B
5. outer R-B is installed and the force from T-B is transferred to only inner race by means of small washer
6. Outer R-B is constrained by means of not or bolt with a small washer so it only contacts inner race.
(outer race is not loaded axially)

The key component that determines the T-B and R-B position is the washer (shim) that is placed between the two bearings.

Big washer with big inner hole to clear inner race of R-B means T-B has to be placed nearer to the blade
Small washer with small outer diameter to clear outer race of R-B means T-B has to be placed nearer to the root or hub.

[Mark A Smith]

Hey Guys,I hovered mine with the thrust set up,:thumbdown: Took em back off and threw em in the gaui spare parts can! The play is tremedous and the control in flight was terrible.Felt
like the tail on a old original shuttle:shock: Bought the tail set up from cnc and it is perfect.Can run the higher h/s (2100) and the tail is spot on.Now my 401 is working the way it should.:happyd had the same problem as far as the base of the holder hitting the hub when the bolts were snugged down.I have to say though,after all the cnc upgrades,tweaking and such,I still really like this heli.I'ts the perfect size and the performance will scare the S--- out of me if I get a little to cocky:wow2: "I AINT GOT IT"

Mark Smith:cheers

[slo_dave]

I agree, what a waste of damn money :mad::mad::mad:
There is no way to tighten up the grips and get rid of the EXCESSIVE play without locking up the hub.
Poor design,,,,junk

I KNEW I should have bought the Align thrusted tail...had my Readyheli order up...had the align tail in the cart then backed it out and said..let's stick with Gaui.

It's almost like they forgot a step. It is the same grip but they just swapped out one of the 4mm radials for a 3.5mm thrust setup and there is no way to get rid of the slop.
Took em back off and threw em in the gaui spare parts can!

Mine are going in the garbage

[Tom Viper]

The align hub is the same, sloppy as h_ll. But, in flight they straighten out, just like the Gaui one.

[istandalone]

i got the align e600 thrusted tail assy and it's tighter then...well i'm not going there. this is pg-13 forum.

[slo_dave]

Just a follow up to put this to bed.

I replaced the new Guai tail with an Align thrusted tail.. H60109T to be exact.
HUGE difference. Just the right amount of play.
I know a thrusted tail is not a rigid as a radial only one but the Guai tail was horrible...maybe I just got a "Monday" one.

Oh well, happy now

Dave

[istandalone]

i think all of the gaui tails were made on monday, the monday after the chinese new year.

[HighNear90]

I just received the new thrusted tail grips and am having problems..

Just received them today
I see two problems
(1) When screwing down to the hub, the grip binds/locks up against the hub at even hand tight
(2) When tightened down all the way the screw protrudes into the hole for the tail output shaft preventing the hub from even being able to be installed.

I'm installing these as shipped:
From blade side I have bearing/small OD race/thrust bearing/large OD race...although I reversed with same result.

Anyone else having same problem or ... no problem with new grips?

To fix #2 I used shorter screws with locktite. There is very little play now. If you put the hub on the shaft and tighten down the stock screws, you will have LOTS of play (too much IMO). About #1, I'm hoping the centrifugal force and the small amount of play will make these perfect. But, in case it doesn't go well, I have the T-Rex 600 tail on stand-by.

Thanks,
Leo

[kahn10]

read this in relation to thrusted tail set ups......him makeum sense.....justin chi's old man



Here is the schematic (in words cause I'm lazy) of how thrust bearing unloads either outer or inner race of R-B.

A Config
1. Grip flange (the part that stops the outer inner most R-B near hub) applies axial load ( along the axis of the shaft )
2. Outer race of the R-B is pushed by the grip. That means inner bearng should not see the axial load.
3. washer is needed so outer race is contacting the T-B and clearance for inner race (free to slide back and forth)
4. washer contacts T-B and Outer race of R-B
5. T-B is installed
6. T-B is constrained by means of nut or bolt with any size washer.
(inner race is not loaded axially)

B. Config
1. Grip applies axial load
2. T-B is pushed by the grip
3. washer is needed so T-B transfers axial load to ONLY inner race
4. washer of same ID as the shaft and small OD so it never contacts the outer race of R-B
5. outer R-B is installed and the force from T-B is transferred to only inner race by means of small washer
6. Outer R-B is constrained by means of not or bolt with a small washer so it only contacts inner race.
(outer race is not loaded axially)

The key component that determines the T-B and R-B position is the washer (shim) that is placed between the two bearings.

Big washer with big inner hole to clear inner race of R-B means T-B has to be placed nearer to the blade
Small washer with small outer diameter to clear outer race of R-B means T-B has to be placed nearer to the root or hub.

[tornet999]

Just curious about this one, is someone using the GAUI thrusted blade holders and happy with it ?
I have installed it but not sure if I want to try ...

[manos]

http://www.helifreak.com/attachment.php?attachmentid=54735&stc=1&thumb=1&d=1215963748
try this

[HighNear90]

Just curious about this one, is someone using the GAUI thrusted blade holders and happy with it ?
I have installed it but not sure if I want to try ...

I flew a few flights and didn't like them, THere was too much slop. I went with the Align 600 tail and it works great.

[JaggedEdge]

Align 600 tail here too. Got to try it this weekend and works great.
Its a direct swap to the 550 tail shaft and tail pitch slider (cnc or plastic).

$16.
http://www.readyheli.com/H60109_New_Tail_Rotor_Holder_p/h60109.htm

http://www.readyheli.com/v/vspfiles/photos/H60109-3.jpg

[ukgroucho]

... Quick UK Raptor 30/50 thrusted tailgrips. CNC (choice of colors) and very nicely made. They bolt straight on. Mine have done a couple of hundred flight so far with no issues, no slop.. in fact absolutely no drama at all.

[JaggedEdge]

... Quick UK Raptor 30/50 thrusted tailgrips. CNC (choice of colors) and very nicely made. They bolt straight on. Mine have done a couple of hundred flight so far with no issues, no slop.. in fact absolutely no drama at all.

Good to know thanks. After screwing around with the Gaui CNC thrusted tail I ended up leaving a bad review of them at readyheli. It's been too long but I want to return them.

[tornet999]

Wanted just to say that I tested the thrust bearing GAUI tail rotor and it was rock solid. I installed it as described by someone else here on forum, used the hub for the blade screws instead.

[JaggedEdge]

Wanted just to say that I tested the thrust bearing GAUI tail rotor and it was rock solid. I installed it as described by someone else here on forum, used the hub for the blade screws instead.

Whats "the hub for blade screws"? It shouldn't require any extra steps especially for the cost. Compared to any other tail hub and grip setup it's not good.

The short hub puts a lot of stress on the bolt. Have you seen the pics of the bolt sheered off where it enters the hub?

[tornet999]

Check this, there is an instruction to how to mount this stuff.
http://www.helifreak.com/showthread.php?t=77567&highlight=tornet999

[JaggedEdge]

Yes, I did that with mine without reading his instructions, wasn't hard to figure that out. For the $$ thats not right.

JMO but the gaui tail is junk. Sorry if that offends you but $40 spent and mine are on the bench and not on the heli because we have to set grip freeplay with the bolt and depend on loctite to hold it there. Not the case with the other side OR with the Gaui stock plastic grips. Sad that the plastic tail is more precisely made than the metal!

The fact that its that way with one grip shows that the other grip could have been machined right. Also, the same hub is used on the Gaui plastic grips and it doesnt have to be setup that way. Pay more for less. <sarcasm> NICE! :thumbup: </sarcasm>