Miks15
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| posted on 7/3/09 at 03:47 PM |
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Fabricated uprights - opinions please
Ive tacked together a front and rear upright. Just wanted some opinions from you lot before i make the other side and fully weld.
So what do you think?
 
Image deleted by owner
Image deleted by owner
[Edited on 7/3/09 by Miks15]
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zilspeed
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| posted on 7/3/09 at 04:14 PM |
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You've missed a big oportunity with the front upright in my opinion.
By using a standard casting and then bolting the fabricated part onto it, it's even heavier and maintains the same geometry as the standard part
which you're using. Both downsides IMHO
If you use a clean sheet and go for either a bolt on or a weld on stub, the rest is wide open regarding design.
It all seems perfectly within your capabilities based on the pics.
All good IMHO. 
Look at how simple and comparatively light this MK upright is.
Also, have a look at the scrub radius compared to what your setup would achieve. Fair enough, you don't want inert steering - you want some
feedback through the wheel, but I tend to think that your setup would be lively in the extreme.
(Unless I'm grabbing the wrong end of the wrong stick - again.)
[Edited on 7/3/09 by zilspeed]
[Edited on 7/3/09 by zilspeed]
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Miks15
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| posted on 7/3/09 at 04:51 PM |
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thanks for the comments zil,
Atm im just looking to get a working car. So small details like that arent going to bother me now. (its not going to go racing or anything like
that)
I have thought about it and it is definatly an option for the future if ever i decide to upgrade bits.
Can anyone see anything wrong with what ive done? The geometry of the front upright is the same as a standard sierra (regarding balljoint points)
Cheers
Mikkel
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james h
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| posted on 7/3/09 at 05:23 PM |
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quote:
Originally posted by zilspeed
Look at how simple and comparatively light this MK upright is.
Hi,
Is that MK upright a straight swap for the sierra item?
Regards,
James
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mr henderson
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| posted on 7/3/09 at 05:27 PM |
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quote:
Originally posted by james h
quote:
Originally posted by zilspeed
Look at how simple and comparatively light this MK upright is.
Hi,
Is that MK upright a straight swap for the sierra item?
Regards,
James
And what is the bottom joint?
John
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minitici
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| posted on 7/3/09 at 07:08 PM |
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And what is the bottom joint?
John
looks like a spherical bearing in a welded housing.
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zilspeed
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| posted on 7/3/09 at 07:31 PM |
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quote:
Originally posted by minitici
And what is the bottom joint?
John
looks like a spherical bearing in a welded housing.
Yes, that's what I thought.
(Honestly, I did.)
Just like the ones McGill sells.
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zilspeed
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| posted on 7/3/09 at 07:46 PM |
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I'm the first to admit that I haven't spent enough time considering the finer points of suspension geometry, so have done a little reading
this afternoon.
Have a look here at the Tony Pashley
book and scroll up a bit to page 27 where the suspension section starts.
Looking at the modified BMW part, there really do appear to be some substantial compromises.
(If any passing racing car designers happen to be reading this thread and they think they might engage me in detailed conversation on this subject
when we next meet, please go easy on me, ok Graham ?)
[Edited on 8/3/09 by zilspeed]
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mark chandler
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| posted on 7/3/09 at 09:01 PM |
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The rear one looks fine to me, it looks like you are intending to use two bolts at the bottom, I would be inclined to weld a tube between the bush
carriers and use a long bolt through both.
Here's what I did, similar but I choose to use rose joints at this end so a long bolt just goes through the lot.
 
Rescued attachment Rear wheel hub small.JPG
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blakep82
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| posted on 7/3/09 at 09:04 PM |
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the back one looks fantastic!
think it'll do you the job nicely.
i think the front one looks a little clumsy. not sure why. but if it works and its safe then it seems all good.
looking at the rear one, your fabrication looks well up to standard, i wonder if maybe you should consider spending a little time making something
similar to zils photo up front? i'm sure you could used the BMW hub, but make an upright to suit?
[Edited on 7/3/09 by blakep82]
________________________
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don't write OT on a new thread title, you're creating the topic, everything you write is very much ON topic!
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mark chandler
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| posted on 7/3/09 at 09:06 PM |
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hung together:
 
Rescued attachment Hung together.JPG
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mr henderson
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| posted on 7/3/09 at 09:36 PM |
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quote:
Originally posted by blakep82
i'm sure you could used the BMW hub, but make an upright to suit?
Not so sure about that. A lot of production cars the upright is one forging (or whatever) including the stub axle.
John
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Miks15
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| posted on 7/3/09 at 10:16 PM |
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quote:
Originally posted by mr henderson
quote:
Originally posted by blakep82
i'm sure you could used the BMW hub, but make an upright to suit?
Not so sure about that. A lot of production cars the upright is one forging (or whatever) including the stub axle.
John
I think what he meant is, reuse the BMW hub, but on a new stub axle.
Thanks for all the comments guys, i will have a look see if it will be worth making a new front one. It would probably look alot neater and perform
better.
Anyone know of anywhere i can get some stub axles with the same dimensions as my BMW one?
Thanks
Mikkel
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mr henderson
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| posted on 7/3/09 at 10:27 PM |
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quote:
Originally posted by Miks15
quote:
Originally posted by mr henderson
quote:
Originally posted by blakep82
i'm sure you could used the BMW hub, but make an upright to suit?
Not so sure about that. A lot of production cars the upright is one forging (or whatever) including the stub axle.
John
I think what he meant is, reuse the BMW hub, but on a new stub axle.
I dare say
quote:
Originally posted by Miks15
Anyone know of anywhere i can get some stub axles with the same dimensions as my BMW one?
Well that's the problem, isn't it. What we are talking about here is combining donor parts with new parts. Stub axles the same dimensions
as BMW units are almost certainly going to have to be specially made, and I can't see that being cheap.
John
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Miks15
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| posted on 7/3/09 at 10:45 PM |
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ye that was my fear,
Can i weld on to the original casting and it still be strong? If so i can cut up the original and make a new bit off of that?
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blakep82
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| posted on 8/3/09 at 12:10 AM |
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well, true enough, the stub axles won't be cheap to have made, hadn't thought of that. but was just an idea i know there's places
where you can buy cortina ones...
________________________
IVA manual link http://www.businesslink.gov.uk/bdotg/action/detail?type=RESOURCES&itemId=1081997083
don't write OT on a new thread title, you're creating the topic, everything you write is very much ON topic!
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mr henderson
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| posted on 8/3/09 at 08:44 AM |
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quote:
Originally posted by Miks15
ye that was my fear,
Can i weld on to the original casting and it still be strong? If so i can cut up the original and make a new bit off of that?
I'm guessing here, but my guess, FWIW, is that no, you can't.
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zilspeed
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| posted on 8/3/09 at 08:47 AM |
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Like these ones
Screw in or weld in - £25 each.
The world, as they say, is your oyster.
If choosing the weld in item, I would have it drilled and threaded in the back to receive a bolt through the back of the upright. I've seen weld
failures in these on little tiny lightweight single seaters. Belt and braces is good.
[Edited on 8/3/09 by zilspeed]
[Edited on 8/3/09 by zilspeed]
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