Liam
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| posted on 12/10/02 at 07:05 PM |
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What we're talking about here is loading in the direction of pulling the ball out of the socket. You RWD people are all OK cos you use a cortina
lower bj which is designed to take load in this direction (cos in a cortina the lower wishbone operates the spring like in a locost).
However us 4x4 people cant use a cortina bj cos it would foul on our front driveshafts and doesn't fit into the sierra 4x4 uprights anyway. We have
to use a lower bj from a FWD car, most of which are McPherson strut. These bjs are NOT designed to take large loads in the
pull-the-ball-out-of-the-socket-direction, cos in a maccy strut car the loads all go through the strut - the bj just takes all the sideways loads of
braking and acceleration and it's designed to do so.
We're wondering whether these bjs will be strong enough to take the pulling suspension loads they would be subject to in a Locost.
...
Anyway - I went down to Halfords today to look at some bjs. They had fiesta ones and told me it is the same part as escort ones. It's the same 17mm
as the sierra 4x4 and has a nice mounting bracket - would be easy to mount it to a wishbone. Actual bj is about the same size as the sierra one.
Here's a picture of the bj - I apologise for the filesize but it needed to be really high quality to show all the detail  ...
But is it strong enough?? Probably. Wish I could remember how beefy the Dax ones were. I'm gonna use these but then mine dont have to take the
load!
Liam
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Cheffy
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| posted on 12/10/02 at 08:16 PM |
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Liam, any photo's or plans anywhere of how you're gonna do your front suspension? Also, how much were the Fiesta/Escort balljoints?
Cheers,
Mart.
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Liam
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| posted on 12/10/02 at 08:30 PM |
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Cheffy,
Bjs were 15 quid each. Haven't got any plans yet but I'll see if I can take a photo of the front of my chassis and draw on what I haven't made yet
so you get the idea! Might work...
My chassis is totally different to the book but my mate did a similar thing (inboard shocks) by slightly modifying the front of a standard chassis.
Liam
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Cheffy
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| posted on 12/10/02 at 08:59 PM |
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Thanks Liam,
Mart.
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stephen_gusterson
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| posted on 12/10/02 at 10:56 PM |
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quote:
I am bit confused by all this about the bottom ball joint taking no load and the strut taking it all. When the car is static or in uniform
motion, yes, this is correct. The difference is when the car is under braking or acceleration. No car on earth can accelerate faster than it can
decelerate and ALL the braking force acts on the lower balljoint on a McP system wheras on a double wish bone system, the load is shared between the
upper and lower joints. Work it out for yourselves, which balljoints have the greater load coefficients.
Also the inertia of a 950cc fiesta (approx 875kg)braking from seventy, will be more that a 500kg locost braking from ninety. I also aked a QH rep at
work about the safety threshold of a standard balljoint, he said they fail at about 7 times their design load.
Basically I aint losing any sleep about balljoint loadings!
Accelleration and braking loads are all sideways or TWISTING loads on the bottom joint.
Acceleration will tend to try and rotate the hub as well as the wheels. A twisting load. Braking will try and rotate the hubs. A twisting load.
Braking will also make the car dive at the front, and that goes into the strut.
The strut takes most of the load - thats where the spring is.
On a locost, the spring goes to the bottom wishbone - therefore the weight of the car is taken there.
Cornering (scrub) forces will also tend to load the bottom joint in a SIDEWAYS loading.
I cant see any normal situation that makes a lower ball joint on a modern ford have to withstand a force thats trying to pull the stud upwards.
If you look at the top wishbone on a locost, its a lot more wimpy than the bottom one - just a tube with a couple tubes welded to the side. The bottom
one had re-enforcement plating at the bottom.
The bottom joint just might have a wonderful load factor. Its just that no one seems to know. And in such a key application, it would be a good idea
to have that info!
atb
steve
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theconrodkid
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| posted on 12/10/02 at 11:03 PM |
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these balljoints are designed to carry a lardy car and ocupants over all manner of road surfaces with iregular check ups and last for many years ,on a
light car with less than average milage and a lot more checking i cant see them going to wear out or break 
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Liam
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| posted on 12/10/02 at 11:50 PM |
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Cheffy - I've put a sophisticated CAD picture of my front suspension in my photo archive. Hope the jpeg compression doesn't make it look like
something a school kid drew...
I'd tend to agree with Conrod bout the strength - production car stuff, especially steering/suspension, is generally extremely overbuilt. Steve -
what about a big high-speed one-wheel bump, say kurbing a wheel in your lardy escort. That pretty instantly twists the 3/4" (or thereabouts) thick
roll bar with an awful lot of force - and all of that force will be acting to pull that lower bj apart - so they will definately be designed to cope
with that kind of load.
Cheffy - dont worry - Ewan will have been on the road for several months before you, using the Sierra lower BJ. So if he still has four wheels on his
wagon you'll probably be OK too  . Maybe ask Tiger about their use of the golf upright/bj on their 4x4 bike engined beast. Or if you've got
80-90 quid, I got Dax's parts department number.
Liam
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Cheffy
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| posted on 13/10/02 at 11:31 PM |
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Cheers Liam. Seriously impressed with the CAD design. Must've taken years of serious study to become that good!!!
Think I'm goin' to look into the 'inboard' idea myself. Will keep you posted.
Cheers,
Cheffy.
Farts are like Rock'n'Roll. You love your own but you hate everybody else's. Lemmy, Motorhead.
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Liam
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| posted on 14/10/02 at 09:20 AM |
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Well why not, but I hereby take no responsibility for further headaches you may experience! But then if you're brave enough to do 4x4 you must have
what it takes.
Couple of things to bear in mind - lots of upwards load on the top wishbone brackets (I might brace mine a bit). Plus my engine is much further back
than a book design which is why I can (comfortably) fit the inboard shockers between the front axle and the engine. The fact it's a V6 helps too.
Good luck. By the way - just had a quick look at your website. That donor car looks a bit nice to cut up! Bet you didn't get that for 50 quid eh?
(if you did can you get me one too?)
Liam
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Cheffy
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| posted on 14/10/02 at 01:44 PM |
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£250 with a weeks MOT - just able to drive it home!!! Had been checked over for MOT but needed new nearside sill, otherwise very tidy.
Like you I'm also movin' the engine back quite a bit. Have had a preliminary look and I'm pretty sure I'll be okay for space.
What are you going to use for top balljoints. With them taking more weight than they would with a traditional wishbone set up d'you reckon the
transit track rod ends will be up to the job?
Re: web site. Between work and building the Locost I'm tryin' to learn how to use Frontpage. Not making too much progress so far but once I do I'll
see about gettin' a decent web site set up.
Cheers,
Cheffy.
Farts are like Rock'n'Roll. You love your own but you hate everybody else's. Lemmy, Motorhead.
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Liam
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| posted on 14/10/02 at 02:12 PM |
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Blimey that's pretty good - I paid 200 for my C-plate MK1 XR4x4 from a couple of criminals in Sheffield. Thought it was a bargain cos it had 10
months tax but the disc turned out to be forged! MOT certificate probably was too. Still I reckon it was still a pretty good buy given that it had a
box of brand new rear wheel bearings in the boot and everything else worked fine.
I keep threatening to do a website too - got plenty of photos and a digicam. My techy IT mate doesn't like Frontpage (probably cos it's by
Microsoft) and says he'll write me some XHTML (or something) which I can 'easily' modify. Hmmmm well I'll see.
I'm still planning to use the transit track rod end for my top joint. It wont be subject to any load pulling the ball out of the socket so it's
pretty much down to the shear strength of the threaded part that fits into the wishbone, which will be more than adequate. My mate did this in his
locost and had no problems. Also Sylva Strikers and Formula 27s use inboard shocks in a similar way and I imagine they probably all use joints
simliar to the transit track rod ends.
Liam
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Cheffy
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| posted on 14/10/02 at 02:17 PM |
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Sounds like that's the way for me then. Off out to the garage to start some serious measuring!!!
Cheers,
Cheffy.
Farts are like Rock'n'Roll. You love your own but you hate everybody else's. Lemmy, Motorhead.
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stephen_gusterson
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| posted on 14/10/02 at 07:34 PM |
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quote:
I keep threatening to do a website too - got plenty of photos and a digicam. My techy IT mate doesn't like Frontpage (probably cos it's by
Microsoft) Liam
if you have a later (like 2000 on) version of microsoft word, that can 'save as an html file' to provide a basic kinda web page from a word
document.
My son has done a page on the final fantasy seven game, on
http://www.brtheoutsider.freeservers.com
just gives an idea of what you can do with something simple.
atb
steve
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Liam
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| posted on 14/10/02 at 09:49 PM |
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Woah, your son must be cool - I spent about 80 hours playing Final Fantasy VII in second year at uni. Best game ever. Housmates couldn't understand
how I could spend so long trying to breed kind of big racing chickens. Really almost cried when Aeris died. Say why's he doing a site about FF VII
when we're on, I believe, FF X by now? Wont you buy him a PS2? I wont let myself buy FF X or I'll never have a Locost  . Really took me back
that did Stevo - Final Fantasy VII eh? Great times.
Er...I'll get me coat.
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stephen_gusterson
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| posted on 14/10/02 at 10:38 PM |
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quote:
Woah, your son must be cool - I spent about 80 hours playing Final Fantasy VII in second year at uni. Best game ever. Housmates couldn't
understand how I could spend so long trying to breed kind of big racing chickens. Really almost cried when Aeris died. Say why's he doing a site
about FF VII when we're on, I believe, FF X by now? Wont you buy him a PS2? I wont let myself buy FF X or I'll never have a Locost . Really
took me back that did Stevo - Final Fantasy VII eh? Great times.
Er...I'll get me coat.
We have two pcs on broadband, and old magadrive, a spectrum (!) a PS1 a Master system, a Nintendo, and yes, a Playstation 2.
Im not into games but my kids are. They have FF 6 thro 10 !!
Phil especially likes 7 and if you look at the bottom of the web page you will see he documented it. Like 640 page story! When I told him he was a bit
sad doing it, he pointed out that building a car over 3 years when you could buy one for less in the paper was alos a bit sad.
cant argue with that!
I have seen the bit with Aeris and it almost bought a tear to my eye too - and i'm being serious......nice the way she just floats down in the water.
Nasty sort that Sepiroth.
get a grip steve.
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johnston
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| posted on 15/10/02 at 08:24 PM |
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here speccys now that is a blast from the past any1 remember the old rubber keyed 48k????
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stephen_gusterson
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| posted on 15/10/02 at 08:42 PM |
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thats what i have here as a museum piece.
they are easy to get hold of.
look on
www.ebay.co.uk
and search for sinclair spectrum
for about 20 quid you could be loading games over 20 mins from your tape player
atb
steve
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