craig1410
|
| posted on 17/3/10 at 11:02 PM |
|
|
quote:
Originally posted by locoboy
They look very similar to the ones i bought from GTS tuning.
Dont GTS supply rally design?
Isn't Darren a poo hot suspension designer................................
Strikingly similar to these
and these
I'd inform Rally Design if I were you because I think you did fit them as intended (wrt to BT) and they have failed due to poor design. I agree
that Ally is a bad material when connected between a steel drag link with steel locknut and steel wishbone. Rally Design should withdraw these from
sale and refund your £9.50. To be honest, £9.50 is way to cheap for something like this if it was designed properly.
Edit: If you look closely at this picture from the GTS Tuning
website you can see a camber adjuster fitted to the top wishbone. Click on the image of the car to enlarge. Looks to me like you did fit it
correctly.
All in my humble opinion of course...
Craig.
[Edited on 17/3/2010 by craig1410]
[Edited on 17/3/2010 by craig1410]
|
|
|
|
|
andyharding
|
| posted on 18/3/10 at 08:06 AM |
|
|
Looks like a bad design to me, over tightening the lock nut is most likely the cause of failure but because the part is hidden you can't tell
you've damaged it until it fails. Can't believe they are made of ally.
Think I'd be bringing small claims against the supplier...
Are you a Mac user or a retard?
|
|
|
alistairolsen
|
| posted on 18/3/10 at 08:40 AM |
|
|
I considered these, but having looked at them, they fit inside a one inch tube from memory giving an OD of about 22mm and are 18.5mm bore across the
outside of the threads leaving a 1.75mm wall thickness with a nice cut thread as a stress raiser. I wouldnt build that in steel never mind alloy.
That said I would always install them with the nut outwards and a half nut on the inside end to lock them. That way they can only fail in a relatively
safe manner.
My Build Thread
|
|
|
boggle
|
| posted on 18/3/10 at 08:44 AM |
|
|
why would you use these over a piece of threaded material welded into the top wishbone???
just because you are a character, doesnt mean you have character....
for all your bespoke parts, ali welding, waterjet, laser, folding, turning, milling, composite work, spraying, anodising and cad drawing....
u2u me for details
|
PLEASE NOTE: This user is a trader who has not signed up for the LocostBuilders registration scheme. If this post is advertising a commercial product or service, please report it by clicking here.
|
iank
|
| posted on 18/3/10 at 08:59 AM |
|
|
quote:
Originally posted by boggle
why would you use these over a piece of threaded material welded into the top wishbone???
Because that would only be adjustable by a whole thread, these give infinite adjustment.
--
Never argue with an idiot. They drag you down to their level, then beat you with experience.
Anonymous
|
|
|
alistairolsen
|
| posted on 18/3/10 at 09:00 AM |
|
|
because you can adjust them by a tiny amount, without removing the ball joint. With threaded bones you're restricted to a full turn of the ball
joint on asymmetric wishbones (which they will be on a book locost chassis with appropriate castor) which i s~1mm
My Build Thread
|
|
|
boggle
|
| posted on 18/3/10 at 10:29 AM |
|
|
i see......
just because you are a character, doesnt mean you have character....
for all your bespoke parts, ali welding, waterjet, laser, folding, turning, milling, composite work, spraying, anodising and cad drawing....
u2u me for details
|
PLEASE NOTE: This user is a trader who has not signed up for the LocostBuilders registration scheme. If this post is advertising a commercial product or service, please report it by clicking here.
|
eddie99
|
| posted on 18/3/10 at 11:11 AM |
|
|
As said earlier, I think this is a one off problem and maybe something else caused it. Lots of people run these adjusters on their cars and i
haven't heard of a problem before and i bet alot of them have been thrashed around a track!
http://www.elitemotorsporteng.co.uk/
Twitter: @Elitemotoreng
Facebook: http://www.facebook.com/pages/Elite-Motorsport-Engineering/153409081394323
|
NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
|
Liam
|
| posted on 18/3/10 at 11:28 AM |
|
|
HOLY POO!! This is shocking!
They could be made of chocolate if the ball joint went all the way through and there were nuts on both sides as BT describes, but looking at the
pictures this doesn't seem to be the case. In fact it's definately not the case or it couldn't have failed and come apart like that
at all!
Given that this design therefore relies entirely on the tensile strength of the adjuster to stay in one piece, it just beggars belief it's so
thin and made of anodized ally!! In fact of course it's far weaker even than the part's tensile strength when you consider
fatigue/endurance - a double whammy against choosing ally.
I take it it snapped pretty much right where the ball joint shank ended? I literally can't believe this product was sold. Wouldn't even
trust a steel one that thin personally.
Eeek!
Liam
|
|
|
alistairolsen
|
| posted on 18/3/10 at 11:35 AM |
|
|
I suspect this was how it was fitted when it failed:
and IMO it should be reversed and the half nut on the inboard side but as stated earlier you would need a short housing tube or a very long track rod
end to have enough thread.
My Build Thread
|
|
|
eddie99
|
| posted on 18/3/10 at 11:36 AM |
|
|
quote:
Originally posted by turbodisplay
I can't believe it is ali, it looks like it due to being anodised. I`m not a material designer but i wouldn`t use ali, nor would I anodise it,
that makes it more brittle!
Darren
Where did you get that from? Anodising doesn't make a material more brittle!!!
http://www.elitemotorsporteng.co.uk/
Twitter: @Elitemotoreng
Facebook: http://www.facebook.com/pages/Elite-Motorsport-Engineering/153409081394323
|
NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
|
iank
|
| posted on 18/3/10 at 11:41 AM |
|
|
quote:
Originally posted by eddie99
quote:
Originally posted by turbodisplay
I can't believe it is ali, it looks like it due to being anodised. I`m not a material designer but i wouldn`t use ali, nor would I anodise it,
that makes it more brittle!
Darren
Where did you get that from? Anodising doesn't make a material more brittle!!!
http://resources.metapress.com/pdf-preview.axd?code=mj50343764u6001m&size=largest
The anodised film is brittle and if it cracks they propagate into the base alloy.
[Edited on 18/3/10 by iank]
--
Never argue with an idiot. They drag you down to their level, then beat you with experience.
Anonymous
|
|
|
eddie99
|
| posted on 18/3/10 at 11:44 AM |
|
|
Oh ok i stand corrected. My thoughts were that yes the coating is more brittle but it doesn't affect the actual ally.
http://www.elitemotorsporteng.co.uk/
Twitter: @Elitemotoreng
Facebook: http://www.facebook.com/pages/Elite-Motorsport-Engineering/153409081394323
|
NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
|
Liam
|
| posted on 18/3/10 at 11:50 AM |
|
|
quote:
Originally posted by eddie99
quote:
Originally posted by turbodisplay
I can't believe it is ali, it looks like it due to being anodised. I`m not a material designer but i wouldn`t use ali, nor would I anodise it,
that makes it more brittle!
Darren
Where did you get that from? Anodising doesn't make a material more brittle!!!
The surface is harder and more prone to cracking, or there can be surface defects caused by the anodizing process itself. Either of these can be
nucleation points for cracks propogating further into the component, eventually leading to failure.
Edit: Darn beaten to it!
[Edited on 18/3/10 by Liam]
|
|
|
eddie99
|
| posted on 18/3/10 at 12:05 PM |
|
|
Thinking about it some more....
I actually suspect that the tube of your wishbones was too big and not the correct size for the adjuster. Therefore it would twist and could fail. But
i suspect thats the only thing. Where did you get wishbones from?
Regards
Ed
http://www.elitemotorsporteng.co.uk/
Twitter: @Elitemotoreng
Facebook: http://www.facebook.com/pages/Elite-Motorsport-Engineering/153409081394323
|
NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
|
boggle
|
| posted on 18/3/10 at 12:20 PM |
|
|
so im thinking you have to have a special top wishbone to take these, or do you have to drill out the tube???
just because you are a character, doesnt mean you have character....
for all your bespoke parts, ali welding, waterjet, laser, folding, turning, milling, composite work, spraying, anodising and cad drawing....
u2u me for details
|
PLEASE NOTE: This user is a trader who has not signed up for the LocostBuilders registration scheme. If this post is advertising a commercial product or service, please report it by clicking here.
|
eddie99
|
| posted on 18/3/10 at 12:23 PM |
|
|
quote:
Originally posted by boggle
so im thinking you have to have a special top wishbone to take these, or do you have to drill out the tube???
Maybe not a "special" one. But obviously it was designed for a certain type etc.. etc.. It's not designed for any wishbone if you
get me....
http://www.elitemotorsporteng.co.uk/
Twitter: @Elitemotoreng
Facebook: http://www.facebook.com/pages/Elite-Motorsport-Engineering/153409081394323
|
NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
|
Peteff
|
| posted on 18/3/10 at 12:38 PM |
|
|
To put a nut on both ends the track rod thread would have to be 6" long and the thread protrude both ends. They would have to be specially made
but if you could do that you would not need to buy the adjuster, just use a close fitting top tube.
yours, Pete
I went into the RSPCA office the other day. It was so small you could hardly swing a cat in there.
|
|
|
craig1410
|
| posted on 18/3/10 at 12:57 PM |
|
|
quote:
Originally posted by eddie99
quote:
Originally posted by boggle
so im thinking you have to have a special top wishbone to take these, or do you have to drill out the tube???
Maybe not a "special" one. But obviously it was designed for a certain type etc.. etc.. It's not designed for any wishbone if you
get me....
Perhaps more importantly you would need to be sure that the inboard end of the wishbone tube had been squared off properly in a lathe to ensure that
it wasn't placing all the compression load caused by the locknut into one point.
I still say it is a bad design and when a pair only costs £9.50 from Rally Design you can tell that it isn't going to be aircraft spec alloy or
quality which is what I would be wanting before I would entertain such a poor design.
|
|
|
flak monkey
|
| posted on 18/3/10 at 01:04 PM |
|
|
IIRC the OD of the adjuster is about 21mm (normally fitted to 2mm wall, 25mm od tube) and the thread is M18, so that gives you 1.5mm radially which
should be more than enough strength wise if the adjusters are steel or 6063T6 or similar. Yes there is a potential for fatigue and galvanic corrosion
if ali adjusters are used, but I doubt this would be a problem on our style of car due to the low milage and general dry, summer only use.
RE stress raisers - the tips of the thread are far from sharp, they will have a root radius of around 0.25mm which is enough to prevent a stress
raiser in that area. It should also be pointed out that this becomes a moot point if the adjusters are fitted correctly.
Its also worth checking the length of the adjuster. If the adjuster is too long for the tube then the assembly wouldnt be clamped tight in the wihbone
allowing some play which would cause premature failure. The adjuster should sit at least 0.75mm inside the wishbone tube.
I havent heard of any other failures, and there are a lot of these fitted to cars now and they have had a lot of track use too.
I wont be changing mine in a hurry.
[Edited on 18/3/10 by flak monkey]
Sera
http://www.motosera.com
|
|
|
iank
|
| posted on 18/3/10 at 01:04 PM |
|
|
quote:
Originally posted by craig1410
quote:
Originally posted by eddie99
quote:
Originally posted by boggle
so im thinking you have to have a special top wishbone to take these, or do you have to drill out the tube???
Maybe not a "special" one. But obviously it was designed for a certain type etc.. etc.. It's not designed for any wishbone if you
get me....
Perhaps more importantly you would need to be sure that the inboard end of the wishbone tube had been squared off properly in a lathe to ensure that
it wasn't placing all the compression load caused by the locknut into one point.
...
Well worth checking the wishbone tube is true before fitting another - even a steel replacement.
Ideally they would be made from a steel forging.
--
Never argue with an idiot. They drag you down to their level, then beat you with experience.
Anonymous
|
|
|
eddie99
|
| posted on 18/3/10 at 01:07 PM |
|
|
Heres some figures:
OD of the camber adjuster is 22mm
Thread is 18
AREA = 502.65mmsquared
Tensile strength - 120n/mmsquared
So 6 tons
600kg car?
70% under weight at front under breaking? 210kg then per corner
Lets say the stress raiser in the corner and the thread is a factor of 6, the camber adjuster can handle 6000 kg's divide by 6 = 1000kg
add in some factor for Fatigue etc.. and still well in????
http://www.elitemotorsporteng.co.uk/
Twitter: @Elitemotoreng
Facebook: http://www.facebook.com/pages/Elite-Motorsport-Engineering/153409081394323
|
NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
|
flak monkey
|
| posted on 18/3/10 at 01:17 PM |
|
|
You need to factor in G, but your factor of 6 is more than adequate to encompass that too.
[Edited on 18/3/10 by flak monkey]
Sera
http://www.motosera.com
|
|
|
Toltec
|
| posted on 18/3/10 at 01:54 PM |
|
|
quote:
Originally posted by eddie99
Heres some figures:
OD of the camber adjuster is 22mm
Thread is 18
AREA = 502.65mmsquared
Tensile strength - 120n/mmsquared
So 6 tons
Pi times radius squared so
Pi x 121 - pi x 81 = 125.66mmsquared
So following the rest of your calculations we get 250kg not 1000kg.
More marginal?
|
|
|
craig1410
|
| posted on 18/3/10 at 02:25 PM |
|
|
quote:
Originally posted by flak monkey
You need to factor in G, but your factor of 6 is more than adequate to encompass that too.
[Edited on 18/3/10 by flak monkey]
It's not actually that simple. You need to look at lateral loads at the contact patch which will be approximately vertical load times tyre
friction coeff. Then you will have a leverage ratio to contend with where the upright will pivot about the lower balljoint and therefore apply
compression and tension loads to the upper wishbone. You also have the upper wishbone angle to contend with although it will be less of an issue.
However, having said all that, you don't (to my knowledge) know what the breaking strain of the camber adjusters actually is or even what
material they are made from. There are also no instructions (that I know of) about which way around to fit them other than the picture I mentioned
earlier from the GTS website showing the head of the adjuster inboard which is how most people seem to fit them. And there is no information on
suitable wishbone tube sizes or torque settings for the locknut. Dynamically you need to think about maximum steady state loading and then add shock
loading factors and then a safety margin. You also need to think about fatigue effects which can significantly lower breaking strength over time.
Far too many variables to consider this in any way, shape or form and "engineered" solution.
Sorry in advance, not meaning to wind anyone up with my comments...
|
|
|
