Glenn
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posted on 28/5/03 at 12:14 AM |
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ali sierra upright inserts ?
just wondered if anyone had tried using ali to make the sierra inserts. I have a machine shop at my disposal and will be making some for myself.
thoughts ? comments ?
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auzziejim
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posted on 28/5/03 at 08:30 AM |
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instead of going to all the hassle why not buy them off MK? i know i would
Cheers
James
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Glenn
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posted on 28/5/03 at 10:09 AM |
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quote: Originally posted by auzziejim
instead of going to all the hassle why not buy them off MK? i know i would
Cheers
James
No hassle at all, it will take me about 1/2 an hour to make a pair and cost me nothing, the true sprit of locost
I dont think the mk ones are ali, so i'll be saving a little weight aswell.
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kingr
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posted on 28/5/03 at 01:27 PM |
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Luego charge about £66 IIRC for ali mushrooms, so sounds like a good idea to me!
One thing to consider is that steel tapers into ali tapers may be problematic because the steel can deform the ali. Presumably this can be got around
by choice of ali though.
Kingr
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Glenn
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posted on 28/5/03 at 01:45 PM |
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quote: Originally posted by kingr
One thing to consider is that steel tapers into ali tapers may be problematic because the steel can deform the ali. Presumably this can be got around
by choice of ali though.
Kingr
I will probally use somthing like dural (Al95/Cu 4/Mg 1) its a high strength, as good as low-carbon steel.
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ChrisW
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posted on 28/5/03 at 02:14 PM |
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Luego ones are ali. They're quite pricey but I think that's because the top hole is offset and at an angle to enable you to tweak the
caster angle. Would be pretty tricky to make I expect?? No need to have that facility if you wanted to save the hassle tho.
Chris
[Edited on 28/5/03 by ChrisW]
My gaff my rules
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James
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posted on 28/5/03 at 03:01 PM |
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quote: Originally posted by ChrisW
Luego ones are ali. They're quite pricey but I think that's because the top hole is offset and at an angle to enable you to tweak the
caster angle. Would be pretty tricky to make I expect?? No need to have that facility if you wanted to save the hassle tho.
Chris
[Edited on 28/5/03 by ChrisW]
MK ones are steel (hardened I presume) with an offset taper. £40 a pair.
ChrisW, it's easy to do the offset taper with a 4 jaw chuck in the lathe.
Cheers,
James
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Glenn
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posted on 28/5/03 at 03:17 PM |
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quote: Originally posted by James
MK ones are steel (hardened I presume) with an offset taper. £40 a pair.
ChrisW, it's easy to do the offset taper with a 4 jaw chuck in the lathe.
Cheers,
James
yes, but not so easy with the angle, I have seen pictures of these. Easy enought to do on the mill but i dont need to bother. Im planning on making
adjustable top wishbone arms to allow castor adjustment.
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James
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posted on 29/5/03 at 09:00 AM |
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MK ones are not at an angle.
Is there a benefit to having an angle? If anyone know I'd be interested...
Cheers,
James
[Edited on 29/5/03 by James]
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Glenn
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posted on 29/5/03 at 10:16 AM |
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quote: Originally posted by James
MK ones are not at an angle.
Is there a benefit to having an angle? If anyone know I'd be interested...
apart from making them a pain in the arse to make, no (well not that I can think of)
you would also have to make the inside of the insert at the same angle for the nut, more awkward machining
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GO
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posted on 29/5/03 at 11:00 AM |
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I can only think its so that the balljoint has maximum movement in all directions when in the suspension is in a neutral position - I don't know
if this would be an issue though - my chassis is still sitting on the floor!
However, if this is the case then it would be severly limiting the amount of camber adjustment available from having it offset.
Dont know really, just my best guess!
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Glenn
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posted on 29/5/03 at 11:43 AM |
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I would also think that it would cause some uneven loading on the joint itself. I know they are designed to withstand massive forces but having the
tapered arm sitting @ an angle would be unnatural.
I would say its best to follow the best and I haven't seen anything like this on any race cars
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craig1410
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posted on 29/5/03 at 11:58 AM |
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Isn't the "angle" to ensure that the transit balljoint is central otherwise it has to be virtually at full angle of misalignment and
can lock up under extreme suspension bump.
I'm sure it was something like that...
Cheers,
Craig.
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craig1410
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posted on 29/5/03 at 12:00 PM |
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Just ignore me please....I just realised that there was a second page to the thread which already answered the question...Doh!
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James
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posted on 29/5/03 at 12:24 PM |
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quote: Originally posted by craig1410
Isn't the "angle" to ensure that the transit balljoint is central otherwise it has to be virtually at full angle of misalignment and
can lock up under extreme suspension bump.
I'm sure it was something like that...
Cheers,
Craig.
No, I won't ignore you!
I think you may be right actually (assuming I understand what you're saying).
MK compensate for this 'angle' by having the threaded wishbone tube pointing 'up' at a slight angle as opposed to straight
out.
James
[Edited on 29/5/03 by James]
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craig1410
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posted on 29/5/03 at 12:28 PM |
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Yes, that is what I was suggesting.
Cheers,
Craig.
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Glenn
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posted on 29/5/03 at 01:10 PM |
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Ok , makes sense.
but if you put the angle in the inserts and then you adjust the camber by rotating the inserts the angle will become twisted.
(confusing) anyone got a picture ???
I think I will follow the Mk approach and angle the threaded part of the top wishbone
[Edited on 29/5/03 by Glenn]
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James
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posted on 29/5/03 at 01:48 PM |
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quote: Originally posted by Glenn
but if you put the angle in the inserts and then you adjust the camber by rotating the inserts the angle will become twisted.
[Edited on 29/5/03 by Glenn]
I'm not sure if it would because the ball joint angle will change to compensate won't it? (although it will affect the nut on
underside!)
Anyway, it's easier to change the angle of the threaded bush than it is to cut the taper at an angle so who cares!
Cheers,
James
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kiwirex
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posted on 29/5/03 at 07:43 PM |
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> but if you put the angle in the inserts and then you adjust the camber by
> rotating the inserts the angle will become twisted.
No.
Well, yes, if you rotate the inserts, the angle will become twisted, but you don't adjust that way.
If your taper is on an angle you'd leave it set the one way (dead vertical at ride height for preference).
Angled or not, you'd adjust by screwing the top ball joint in and out of the threaded bit (technical term) in the top wishbone.
The advantage of angling the taper is that your top wishbone can then be straight.
Might be a minor strength / rigidity advantage?
- Greg H
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Glenn
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posted on 29/5/03 at 09:16 PM |
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quote: Originally posted by kiwirex
> but if you put the angle in the inserts and then you adjust the camber by
> rotating the inserts the angle will become twisted.
No.
Well, yes, if you rotate the inserts, the angle will become twisted, but you don't adjust that way.
- Greg H
woops, sorry meant to say castor, which, with an offset hole in the insert you would adjust by rotating the insert itself.
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kingr
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posted on 30/5/03 at 09:01 AM |
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But not without affecting camber/KPI/Scrub radius...... Although you can compensate camber.
Kingr
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James
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posted on 30/5/03 at 10:34 AM |
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quote: Originally posted by kiwirex
> but if you put the angle in the inserts and then you adjust the camber by
> rotating the inserts the angle will become twisted.
No.
Well, yes, if you rotate the inserts, the angle will become twisted, but you don't adjust that way.
If your taper is on an angle you'd leave it set the one way (dead vertical at ride height for preference).
Angled or not, you'd adjust by screwing the top ball joint in and out of the threaded bit (technical term) in the top wishbone.
The advantage of angling the taper is that your top wishbone can then be straight.
Might be a minor strength / rigidity advantage?
- Greg H
If you can't twist the insert then you're losing a major benefit of having the offset hole which is that it gives you adjustable castor.
It also gives you more flexibility in camber setup (although this is mainly adjustable via winding the BJ in or out).
Is there a massive benefit to having the top wishbone straight? If having it at an angle is good enough for MK then it's good enough for me!
Cheers,
James
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Glenn
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posted on 30/5/03 at 10:45 AM |
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quote: Originally posted by kingr
But not without affecting camber/KPI/Scrub radius...... Although you can compensate camber.
Kingr
well as you say, camber can be re-adjusted with the top joint.
KPI, I assume you mean king pin Inclination, can't see that this would be changed ??
scrub radius, do you mean akermann steer angles ?? if so this is can be adjusted by changing the angle of the front steering arms, ok ours are cast
as part of the hub, but hay ho there is always some off-set to the dark side
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kingr
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posted on 30/5/03 at 01:07 PM |
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The Kingpin inclination is the angle of the line that passes directly through the ball joints, so moving one in relation to the other will affect
this. Scrub radius, IIRC is the distance between the centre of the tyre, and the point at which the line through the ball joints intersects the
ground. Don't take these as gospel by any means, there are other people on this forum who know a lot more about these things, so I'll let
them correct me if need be, and tell you the extent to which these things will be affected. Basically, the crux of this is that you may be better off
design the insert to be static and adjusting the castor by making your wishbone brackets over-sized and packing them out with washers, allowing you to
move the wishbones back and forth a few mm.
Kingr
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Glenn
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posted on 30/5/03 at 03:57 PM |
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quote: Originally posted by kingr
The Kingpin inclination is the angle of the line that passes directly through the ball joints, so moving one in relation to the other will affect
this.
correct but KPI is the angle measured as seen from the side But when adjusting castor you are adjusting the front/back position of the upright, if you
re-set your camber using the top balljoint the KPI will remain the same.
i will do a picture if it helps, it's very difficult to explain without one.
quote: Scrub radius, IIRC is the distance between the centre of the tyre, and the point at which the line through the ball joints intersects the
ground.
This is genrally reffered to as king-pin offset
quote:
Don't take these as gospel by any means, there are other people on this forum who know a lot more about these things, so I'll let them
correct me if need be, and tell you the extent to which these things will be affected. Basically, the crux of this is that you may be better off
design the insert to be static and adjusting the castor by making your wishbone brackets over-sized and packing them out with washers, allowing you to
move the wishbones back and forth a few mm.
Kingr
No, I dont like the idea of shimming my wishbones, i know it's done but i would rather have my brackets correctly sized i just think it looks
tatty.
Cheers
Glenn
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