britishtrident
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| posted on 14/3/05 at 08:28 AM |
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quote:
Originally posted by gazza285
I know shot peaning is used to reduce stress raisers but to toughen alloy surfaces, that's a new one on me.
Bead blasting rather than shot on alumium I wiuld expect Same thing really it should introducescompressive residual stress and gets rid of tensile by
physically impacting the surface -- as aluminium work hardens it must harden the surface layers in the process.
[Edited on 14/3/05 by britishtrident]
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Deckman001
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| posted on 17/3/05 at 02:21 PM |
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Chaps, might be able to get a deal on the Bearings if i can get enough interest , can also get the cnc shop to fit them as well at a cost,
havn't found that bit out yet though as i was after peoples thoughts on me getting the whole package first
Jason
Eek,lasses as welll,,, sorry
[Edited on 17/3/05 by Deckman001]
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ned
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| posted on 17/3/05 at 02:31 PM |
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well, i've only just put new bearings in the iron hubs, but the last lot were a bitch to get out i think (it was so long ago now) how much extra
would it be?
Ned.
beware, I've got yellow skin
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Deckman001
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| posted on 17/3/05 at 02:50 PM |
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Won't know till i get an idea of how many to order, if it's 50 bearings kits then it will be under £10 each plus fitting, which i
don't have a cost for
Jason
eek, bearing price has gone up to £12.50
[Edited on 22/3/06 by Deckman001]
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MikeR
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| posted on 17/3/05 at 02:57 PM |
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i think its the fitting cost that i'm most curious about. Darrens web site lists them at 15.50 each so any figure less than that is a bargin
(unless you've already got your bearings like me!)
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Deckman001
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| posted on 17/3/05 at 03:01 PM |
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I'll get a set next time i pass the place and when the first set are ready, I'll get them to fit em and then get a definate cost for each
hub
Jason
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ned
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| posted on 17/3/05 at 03:05 PM |
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Jason,
when the first set is done can you get an approx weight? i know it makes little difference as they'll be shed loads lighter anyway but i saw a
set the other day that were slotted between the wheel stud holes to lose even more weight. may have been the racedla ones..
Ned.
beware, I've got yellow skin
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Deckman001
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| posted on 17/3/05 at 03:10 PM |
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Yep, will do 
Jason
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robby
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| posted on 17/3/05 at 04:19 PM |
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definite for me too, if they're still there! cheers!
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Deckman001
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| posted on 17/3/05 at 04:22 PM |
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robby, you have been added
Jason
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robby
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| posted on 18/3/05 at 12:10 PM |
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cheers man!
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jcduroc
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| posted on 30/3/05 at 02:59 PM |
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quote:
Originally posted by NS Dev
It's nothing to worry about, no need for peening etc, as long as the fit is tighter than that used on a steel housing, that's all, ...
How tight a fit, I mean, in terms of tolerances?
JCM
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cymtriks
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| posted on 30/3/05 at 09:03 PM |
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Fitting bearings...
quote:
Originally posted by James
quote:
Originally posted by NS Dev
That sounds right, yes. The alloy will tend to get "hammered" by the bearing outer race as it rotates and then allow the outer race to
"walk" around in the hub.
So yes, the race will probably want to be a shrink fit or good press fit.
Haing said that, I havent done it so I don't know!
It would be easy and cheap to get the bearing area of the hub shot peened to toughen it up if it's a worry.
Cheers,
James
[Edited on 11/3/05 by James]
Do not shot peen. This will increase the diameter of the bore which may make the problem worse.
Fit the outer rings with an appropriate fit. If you want to work it out for youself it's easy to do. Just take the difference between the
expansion coefficient of the alluminium and of the steel bearing (this difference will be about 11 x 10e-6) and multiply it by the diameter of the
bearing OD and by the temperature rise in the hub.
so that's
11 x 10e-6 times OD times temprise
add this to the interference fit on the bearing as fitted to the steel hub (measure a couple of steel hubs with an internal micrometer)
At this point you'll be asking how you get the temperature of the hub?
There are some pointers to this:-
Use thermal paint that changes colour according to the temperature reached.
Splash a little water on a hub that's just done a few miles. No hiss and it's under 100C.
Check for the thermal limits on the grease recommended for the original hub bearings.
So if the hub is at 70C then the rise is about 50C assuming that the bearings and hubs are fitted at 20C.
One important point. If the fit is too high you'll crush the bearing and it will fail early.
Why not investigate which bearings are used on an existing proven design of alloy hub such as an Elise or Westfield hub? I've heard the Elise
uses MGF bits in the hubs.
NSdev, you mentioned brinelling and you live in Stroud. Do you work at Aerospace Bearings in Stonehouse by any chance? I used to work there!
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Deckman001
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| posted on 6/4/05 at 07:38 AM |
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Hi peeps, am looking at the Bearings options at the moment, looks like either 'cheap' ones or Timken, can the people on the list on page 4
u2u me their preference , I'm going to need a group buy for these to get a discount to pass on !!
I'm guessing the other option would be to get these Hubs plain, and let you all fit the bearings yourslves,,, your call
Cheers peeps
Jason
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Deckman001
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| posted on 7/5/05 at 02:11 PM |
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The test Hubs are being finnished today and then being fitted with Timken Bearings, I'm picking them up on tuesday ,ready for the testing,
I'll post a price on tuesday after i speak to the miller 
Jason
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WIMMERA
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| posted on 8/5/05 at 12:53 AM |
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I would be more concerned about the prospect of losing bearing running clearance as the hubs warm up and the distance between the bearing cups
increases as the alloy expands, reducing bearing clearance, which generates more heat and so on.
Wimmera
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Deckman001
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| posted on 8/5/05 at 07:27 AM |
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I would be too , if it wasn't for the fact that Cater*** sell them ,Westf**** sell them and so do lots of other companies, also the company that
are making mine are ISO certified and also make components for the aero industry
Jason
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WIMMERA
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| posted on 8/5/05 at 11:51 AM |
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What maximum temperature did you specify to the manufacturer.
Wimmera
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Deckman001
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| posted on 8/5/05 at 12:12 PM |
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I gave them the spec for Gp4 rally hubs which includes a heat treatment, they said it was a med quality material spec , aviation spec being the best,
I'm keeping to the GP4 spec as these cars won't be used with the same loading forces as used by production cars (hopefully)so should last
a long time in normal use
Only testing will prove this so it's off to the tester on tuesday Allthough i do have a ex F1 engineer interested in seeing them as well
Time wil tell i guess
ATB
Jason
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Deckman001
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| posted on 9/5/05 at 07:15 PM |
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For Ned's information, and other's i guess,, The weight of the bare hub is 1.08kg
Jason
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Northy
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| posted on 9/5/05 at 07:19 PM |
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pictures?!
Graham
Website under construction. Help greatfully received as I don't really know what I'm doing!
"If a man says something in the woods and there are no women there, is he still wrong?"
Built 2L 8 Valve Vx Powered Avon
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Deckman001
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| posted on 9/5/05 at 07:30 PM |
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Tomorrow, after i get to see them !!
apparently they do look smart !!
Jason
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NS Dev
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| posted on 10/5/05 at 07:38 AM |
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quote:
Originally posted by cymtriks
quote:
Originally posted by James
quote:
Originally posted by NS Dev
That sounds right, yes. The alloy will tend to get "hammered" by the bearing outer race as it rotates and then allow the outer race to
"walk" around in the hub.
So yes, the race will probably want to be a shrink fit or good press fit.
Haing said that, I havent done it so I don't know!
It would be easy and cheap to get the bearing area of the hub shot peened to toughen it up if it's a worry.
Cheers,
James
[Edited on 11/3/05 by James]
Do not shot peen. This will increase the diameter of the bore which may make the problem worse.
Fit the outer rings with an appropriate fit. If you want to work it out for youself it's easy to do. Just take the difference between the
expansion coefficient of the alluminium and of the steel bearing (this difference will be about 11 x 10e-6) and multiply it by the diameter of the
bearing OD and by the temperature rise in the hub.
so that's
11 x 10e-6 times OD times temprise
add this to the interference fit on the bearing as fitted to the steel hub (measure a couple of steel hubs with an internal micrometer)
At this point you'll be asking how you get the temperature of the hub?
There are some pointers to this:-
Use thermal paint that changes colour according to the temperature reached.
Splash a little water on a hub that's just done a few miles. No hiss and it's under 100C.
Check for the thermal limits on the grease recommended for the original hub bearings.
So if the hub is at 70C then the rise is about 50C assuming that the bearings and hubs are fitted at 20C.
One important point. If the fit is too high you'll crush the bearing and it will fail early.
Why not investigate which bearings are used on an existing proven design of alloy hub such as an Elise or Westfield hub? I've heard the Elise
uses MGF bits in the hubs.
NSdev, you mentioned brinelling and you live in Stroud. Do you work at Aerospace Bearings in Stonehouse by any chance? I used to work there!
Crikey, quotes on quotes on quotes!
No, it wasn't me that mentioned the brinelling, although I do have a bit to do with bearings, as I work for Timken! Not in the bearing division,
but in the Alloy Steel division, as a process improvement engineer in a tube piercing mill, formerly TI Tubes Desford Ltd.
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Kissy
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| posted on 10/5/05 at 12:21 PM |
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Ready with the readies!
I'll take 'em as they come, would prefer
1. Timken
2. Bare
3. Cheapies
Like I said, if you need some dosh to get rolling I'd be happy to stump up in advance.
What are the chances of anodising? I'm aware this may change dims.
Cheers.
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Deckman001
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| posted on 10/5/05 at 06:44 PM |
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The bearings are Very hard to fit without the use of a press, so i am going to advise that i supply the hubs with the bearings fitted, the test hubs
do have Timken, so i will try again to get a price on the bulk buying of them so as to be able to pass on the cost saving.
The cost of each Hub will be £47.50 EACH + bearing, i will advise people of the cost of these as soon as i get a reply from the supplier
I hope this makes things a bit clearer
I will be placing the order in about a months time and delivery will be soon after that, I can also order as many extra as i need if your orders are
placed to me before i give the final order to the supplier, No money will be required until i get a delivery date from the supplier, so you can all
keep your money earning interest on your bank accounts
Pictures will follow as soon as i get my proper comp back to life, this laptop won't reduce the pic size sorry
ATB
Jason
[Edited on 16/3/06 by Deckman001]
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