Turbine bearings - RCCanada - Canada Radio Controlled Hobby Forum
RCCanada - Canada's Radio Control Hobby Forum
Jet Aircraft Discuss Jets in Canada

Reply
 
Thread Tools Display Modes
Old 08-09-2020, 03:50 PM   #1
Major Bladebreaker
RCC Junior Contributor
 
Major Bladebreaker's Avatar
 
I am: Mark I
Join Date: Jun 2009
Location: Hamilton Ontario
Radio of choice:
Multiplex Evo 12 2.4g
# of RCs: 15

Feedback: 21 / 100%
Posts: 183
Total Props: -2
Turbine bearings


       Remove this ad - become a site supporter!
Where do you guys get turbine bearings? I bought some online from the u.s. but is there someone in Canada?
Major Bladebreaker is offline   Quick reply to this message.

Sponsored Links - Subscribe to remove this ad.
Old 08-09-2020, 06:56 PM   #2
Cougar429
Level 3 Supporter
★ Site Supporter ★
 
Cougar429's Avatar
 
I am: Gary L
Join Date: Aug 2008
Location: Tecumseh, Ontario

Feedback: 102 / 100%
Posts: 7,339
Total Props: 48
Re: Turbine bearings

Are these ceramic? If so, my own experience would preclude servicing at home. Also, final balancing should be performed, something not likely available in the field.
__________________
I know there's money in aviation........I put it there!
Cougar429 is offline   Quick reply to this message.
Old 08-09-2020, 11:19 PM   #3
stegl
RCC Supreme Contributor
 
I am: Len S
Join Date: Mar 2009
Location: Kelowna
Radio of choice:
DS16 And still use my trusty SD-10.
# of RCs: 10

Feedback: 167 / 100%
Posts: 6,863
Total Props: 43
Re: Turbine bearings

Yes, they would be ceramic bearings and should be available to order at any descent bearing supply place but they would have to know the specs of the bearing and as Gary says then there is balancing .
stegl is offline   Quick reply to this message.
 
Old 08-10-2020, 09:26 AM   #4
darkith
RCC Junior Contributor
 
I am: David L
Join Date: Jul 2010
Location: Fredericton, NB

Feedback: 14 / 100%
Posts: 129
Total Props: 1
Re: Turbine bearings

Ceramic/stainless hybrid angular contact bearings. They have to be rated for both the high speed and the axial loading from preload and thrust.

I’m sure their are other places to find them, but I’ve really only seen decent selection from Bocabearings in the US and Xicoy in Europe. Expect to get dinged for brokerage fees from Xicoy’s shipper...

There was somebody on RCG selling turbine bearings in the Classifieds, but they only had one or two sizes, and no clue on quality.
darkith is offline   Quick reply to this message.
Old 08-10-2020, 11:28 AM   #5
Canadian Man
RCC Contributor
 
Canadian Man's Avatar
 
I am: Jonathan G
Join Date: May 2010
Location: Calgary, AB
Radio of choice:
JR28x

Feedback: 3 / 100%
Posts: 390
Total Props: 1
Re: Turbine bearings

BOCA Bearings online
__________________
Check out my YouTube Channel for Build/Repair Videos.
https://www.youtube.com/c/TheLighterSideOfUs
Jonathan
​​​​​​​
Canadian Man is offline   Quick reply to this message.
Old 08-10-2020, 11:45 AM   #6
stegl
RCC Supreme Contributor
 
I am: Len S
Join Date: Mar 2009
Location: Kelowna
Radio of choice:
DS16 And still use my trusty SD-10.
# of RCs: 10

Feedback: 167 / 100%
Posts: 6,863
Total Props: 43
Re: Turbine bearings

Even BOCA sells varying quality bearings (same size) with different ratings , I have found.
stegl is offline   Quick reply to this message.
Old 08-10-2020, 12:14 PM   #7
darkith
RCC Junior Contributor
 
I am: David L
Join Date: Jul 2010
Location: Fredericton, NB

Feedback: 14 / 100%
Posts: 129
Total Props: 1
Re: Turbine bearings

Boca’s search engine seems to narrow things down to a specific bearing PN for a given turbine model (at least the ones I checked), hopefully they’ve got the right rating/spec chosen in each case.

Choose “Model Seaech”, then “Rc Jet Turbine bearings”, then manufacturer and model...
darkith is offline   Quick reply to this message.
Old 08-10-2020, 01:14 PM   #8
Major Bladebreaker
RCC Junior Contributor
 
Major Bladebreaker's Avatar
 
I am: Mark I
Join Date: Jun 2009
Location: Hamilton Ontario
Radio of choice:
Multiplex Evo 12 2.4g
# of RCs: 15

Feedback: 21 / 100%
Posts: 183
Total Props: -2
Re: Turbine bearings

Hey Folks! Sorry I took so long to get back with you all. In fact, I bought my bearings from boca and you're right, it is a very slick site. They even have a live chat app which I used to make sure I was making the right choice. I have an old Simjet 2300 which I believe is discontinued so parts may be hard to find.
Anyway, you guys have convinced me to go back to Boca in the future. Doesn't look like there's anything reliable/affordable in Canada. Thanks again for your input, all!
While I have your attention, being new to turbines, I'm wondering why I would have to rebalance the turbine shaft after just replacing the bearings? If it has been previously balanced, I'm not changing the mass of anything that that would affect balance greatly, no?
Major Bladebreaker is offline   Quick reply to this message.
Old 08-10-2020, 01:28 PM   #9
HAL9KPCM
Level 3 Supporter
★ Site Supporter ★
 
HAL9KPCM's Avatar
 
I am: Dave Z
Join Date: Jul 2012
Location: Regina, Saskatchewan
Radio of choice:
Futaba 18MZ
# of RCs: 9

Feedback: 17 / 100%
Posts: 2,711
Total Props: 40
Essentially there is little, if any chance of reassembling the shaft to the intake and exhaust vanes exactly the way they were originally assembled. With the RPM involved, you will have vibration that if you're lucky will lead to just premature failure. If you're not so lucky, the failure could be much more damaging.
__________________
Two wrongs don't make a right, but two Wrights will make an airplane.

My Heli: Futaba 18MZ 2x(JR GSR260Z Sports FBL, Zenoah G26H, Futaba CGY750 Gyro, Futaba BLS-351 cyclic, BLS-251 tail, Futaba BLS-451 Throttle. Gryphon voltage regulator).
HAL9KPCM is offline   Quick reply to this message.
Old 08-10-2020, 01:44 PM   #10
darkith
RCC Junior Contributor
 
I am: David L
Join Date: Jul 2010
Location: Fredericton, NB

Feedback: 14 / 100%
Posts: 129
Total Props: 1
Re: Turbine bearings

It’s not just the shaft, it’s the whole rotating assembly.
So, the shaft, turbine wheel, wheel nut, compressor, compressor nut, rpm sensor magnet in the nut, and any bearing spacers on the shaft all have to be in balance. Usually each component is somewhat balanced as a isolated part, but the whole assembly needs to be balanced as unit. (E.g. if the hole in the compressor wheel is off by a minuscule, it may balance independently, but put it on a perfectly balanced shaft and the assembly is off balance, so the assembly also needs to be rebalanced). So, usually one or more parts are ground down (eg compressor nut)to balance the assembled unit. If they’re reassembled with different relative “clocking” angles after bearing replacement, the balance is out. At 150,000-250,000 rpm, a “little off” can be fatal to the turbine.

It is possible to mark the “clocking” of each part (with a fine sharpie) on the shaft, dissemble, then reassemble and maintain adequate balance (if you ensure everything ends up *exactly* back where it was relative to everything else), but it’s quite tricky. For example, if you put the compressor wheel lined up exactly on its marks and then torque the compressor nut to spec, you’ll probably find that the nut has drug the compressor off it’s mark...so remove it, advance it a handful of degrees, try again, repeat, etc. Tedious, but doable. This can get you into adequate spec if done *well*, but is not going to be as good as a proper computerized core balancer job.

There’s also a procedure in the Wren54 home build kit manual (Google it if you’re interested) to hand balance a turbine, involves building a jig on a glass plate and then “spinning/rocking” the shaft to find the heavy point, grinding a bit off, repeat, etc. also tedious, but pretty much the only way to hand balance a core if it’s out of balance. Again, not as good as a computer balancer, and you still have to mark everything, remove it from the jig, and realign marks to install in the bearing tube.

There’s a good thread “ Do It Yourself Turbine Stripdown & Maintenance” on RCU about the topic....for a turbine that’s not worth much, might be worth doing, but in most cases probably too risky.

D.
darkith is offline   Quick reply to this message.
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the RCCanada - Canada Radio Controlled Hobby Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

Member names may only be composed of alpha-numeric characters. (A-Z and 0-9)

!!ATTENTION ADVERTISERS!! If you intend on advertising anything on this forum, whatsoever, you are required to first contact us here . Additionally, we do NOT allow BUSINESS NAMES unless you are an Authorized Vendor. If you own a business, and want to do sales on this site via posting or private message, you will need to follow the rules. Shops, Stores, Distributors, Group Buys without being authorized will see your account terminated.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Radio of choice?
Which radio is your current favorite to use?
Number of RC Vehicles?
How many boats, cars, planes do you own?

Log-in



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
vBulletin Message

Thread Tools
Display Modes

Forum Jump


All times are GMT -5. The time now is 05:07 AM.


vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.