1 or 2 Bearings?

Wildcards · 03-02-2012, 08:49 PM

In the boom on the torque tube?? what are you guys using? I am starting the slow rebuild and I have an extra bearing, does this actually help with vibs at all?

snjbird · 03-02-2012, 09:14 PM

I use two...

Wildcards · 03-02-2012, 10:15 PM

Quote:

Originally Posted by snjbird

I use two...

And so did I

duytang · 03-02-2012, 10:52 PM

did you guys notice any differences with having 2 bearings?

Deet · 03-02-2012, 11:05 PM

One

Always have, in the specified spot

Never a vibe issue, never failed.

Every vibe issue I have tracked down has never been solved by adding another bearing to the TT

pxpep · 03-03-2012, 01:58 AM

Quote:

Originally Posted by Deet

One

Always have, in the specified spot

Never a vibe issue, never failed.

Every vibe issue I have tracked down has never been solved by adding another bearing to the TT

This is so true.
Why not 3 bearings ot maybe 4?

wanderer56 · 03-03-2012, 06:09 AM

Of the 3 TT shafts I've purchased since converting, not one has been very straight. And for the money, I'm not going to do the "Roll it on a flat surface to straighten it out" technique.

Mateyhv · 03-03-2012, 07:41 AM

Tail belt is the way to go, you will never look back and spend money again

Deet · 03-03-2012, 03:21 PM

I have never seen a bent TT , new in packet

Wildcards · 03-03-2012, 05:54 PM

I just never check. I like to assume its straight

Deet · 03-03-2012, 08:18 PM

even if it is bent, 2 bearings can't fix that

tomd27858 · 03-03-2012, 08:49 PM

Quote:

Originally Posted by Deet

One

Always have, in the specified spot

Never a vibe issue, never failed.

Every vibe issue I have tracked down has never been solved by adding another bearing to the TT

same here.

NRPY · 03-03-2012, 09:07 PM

Since I was curious, and my 500 Pro is equipped with an SK-720, I tested the "two TT bearings reduces vibes" theory. The attached screenshots are from the SK-720's vibration spectrum analyzer. The big peak in each plot corresponds to the tail rotor RPM, which is where tail vibes show up.

Bottom line: no significant difference in tail vibes with an additional TT bearing. In fact, two TT bearings resulted in slightly higher vibes, but the results are close enough such the difference can be ignored.

Tomy. · 03-04-2012, 01:02 AM

I had a strange noise a few months back so I added another bearing but it did not help (turned out at the end it was old Boca beraings in the motor). I did not take it out but I don't think there's a significant advantage. I never had a bent torque tube, always checked when pulled a new one from the package.
As for the belt, it was the part that cost me the highest repair cost ever when broke so I ditched the belt setup and never looked back. YMMV.

03-02-2012, 08:49 PM	#1
Wildcards Registered Users Join Date: Apr 2011 Location: San Diego CA.	1 or 2 Bearings? In the boom on the torque tube?? what are you guys using? I am starting the slow rebuild and I have an extra bearing, does this actually help with vibs at all? __________________ USMC - EXPEDITIONARY AIRFIELDS - MCAS MIRAMAR To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. Align Trex 500 Scorpion 3226-1400 powered missile

03-02-2012, 09:14 PM	#2
snjbird Registered Users My HF Map location Join Date: Feb 2008 Location: Kissimmee, FL USA	I use two... __________________ No Plankers were injured in the making of this post! TOY BOX contents Mcp x, 450 Pro VBar, 500 VBar, 12S 600CF VBar... Mikado Logo 6003D VBar Proudly flying KBDD, MKS, Castle, Scorpion and some planks too To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

03-02-2012, 11:05 PM	#5
Deet Registered Users My HF Map location Join Date: Dec 2009 Location: South Australia	One Always have, in the specified spot Never a vibe issue, never failed. Every vibe issue I have tracked down has never been solved by adding another bearing to the TT __________________ Dave Goblin 500, Vbar, BLS153, BLS251, Kontronic Jive & Piro MutliWiiCopter Scarab Stealth Armour, Scarab TriiKopta, Scarab Octa, Scarab Vampire

03-03-2012, 06:09 AM	#7
wanderer56 Registered Users My HF Map location Join Date: Oct 2009 Location: Lafayette, LA., USA	Of the 3 TT shafts I've purchased since converting, not one has been very straight. And for the money, I'm not going to do the "Roll it on a flat surface to straighten it out" technique. __________________ Trex 500-3226-1600, 13T, Koby 90LV, HS-5245MG, DS520, AR7200BX, DFC Trex 450 Sport-450M, 13T, RCE-BL35X, HS-5065MG, HSG-5084MG, DS760 DX8

03-03-2012, 03:21 PM	#9
Deet Registered Users My HF Map location Join Date: Dec 2009 Location: South Australia	I have never seen a bent TT , new in packet __________________ Dave Goblin 500, Vbar, BLS153, BLS251, Kontronic Jive & Piro MutliWiiCopter Scarab Stealth Armour, Scarab TriiKopta, Scarab Octa, Scarab Vampire

03-02-2012, 10:52 PM	#4
duytang Registered Users Join Date: Nov 2011 Location: Edmonton	did you guys notice any differences with having 2 bearings?

03-03-2012, 07:41 AM	#8
Mateyhv Registered Users Join Date: Mar 2011 Location: Spain	Tail belt is the way to go, you will never look back and spend money again

03-03-2012, 05:54 PM	#10
Wildcards Registered Users Thread Starter Join Date: Apr 2011 Location: San Diego CA.	I just never check. I like to assume its straight __________________ USMC - EXPEDITIONARY AIRFIELDS - MCAS MIRAMAR To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. Align Trex 500 Scorpion 3226-1400 powered missile

03-03-2012, 08:18 PM	#11
Deet Registered Users My HF Map location Join Date: Dec 2009 Location: South Australia	even if it is bent, 2 bearings can't fix that __________________ Dave Goblin 500, Vbar, BLS153, BLS251, Kontronic Jive & Piro MutliWiiCopter Scarab Stealth Armour, Scarab TriiKopta, Scarab Octa, Scarab Vampire

03-03-2012, 09:07 PM	#13
NRPY Registered Users Join Date: Aug 2009 Location: California, USA	Since I was curious, and my 500 Pro is equipped with an SK-720, I tested the "two TT bearings reduces vibes" theory. The attached screenshots are from the SK-720's vibration spectrum analyzer. The big peak in each plot corresponds to the tail rotor RPM, which is where tail vibes show up. Bottom line: no significant difference in tail vibes with an additional TT bearing. In fact, two TT bearings resulted in slightly higher vibes, but the results are close enough such the difference can be ignored. Attached Thumbnails

03-04-2012, 01:02 AM	#14
Tomy. Registered Users Join Date: Aug 2010 Location: Redmond, WA	I had a strange noise a few months back so I added another bearing but it did not help (turned out at the end it was old Boca beraings in the motor). I did not take it out but I don't think there's a significant advantage. I never had a bent torque tube, always checked when pulled a new one from the package. As for the belt, it was the part that cost me the highest repair cost ever when broke so I ditched the belt setup and never looked back. YMMV. __________________ I am a HeliCoholic! To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. Fusion50FBL μBeast TRex500FBL μBeast Blade 130X Blade Nano Spektrum DX8 Blade 120SR handbuilt Coastguard AW109 see my avatar For the winter:Reflex XTR

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