SyKaTurbo
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| posted on 26/9/07 at 08:47 AM |
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Are None Of The Wishbones Supposed To Fit Into The Brackets??
When I have come to fit the wishbones into the chassis brackets they are about 5mm out which means that I will need to hammer the brackets into
place!!
How do you think this will affect the overall strength of the bracket and chassis?
Any help or ideas greatly appreciated as they all seem to be the same!!
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wilkingj
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| posted on 26/9/07 at 08:55 AM |
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Chassis and wishbones from the same manufacturer?
1. The point of a journey is not to arrive.
2. Never take life seriously. Nobody gets out alive anyway.
Best Regards
Geoff
http://www.v8viento.co.uk
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BenB
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| posted on 26/9/07 at 08:58 AM |
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Often the brackets are slightly open IE more like \_/ than |_| and when you tighten the bolt it squashes the arms parallel.
It's also not that unusual to need a packing washer (or two) on both sides of the wishbone to pack them out.
Certainly it's important that the arms don't go /_\
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SyKaTurbo
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| posted on 26/9/07 at 08:58 AM |
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Yes, they are both from the MK Kit
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SyKaTurbo
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| posted on 26/9/07 at 09:01 AM |
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quote:
Originally posted by BenB
Often the brackets are slightly open IE more like _/ than |_| and when you tighten the bolt it squashes the arms parallel.
It's also not that unusual to need a packing washer (or two) on both sides of the wishbone to pack them out.
Certainly it's important that the arms don't go /_
so when i pack it out do the washers need to be the same overall diameter as the sleeve so i am not gripping the polybush?
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westcost1
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| posted on 26/9/07 at 09:06 AM |
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That doesn’t look good  id be having words with mk if I was you
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D Beddows
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| posted on 26/9/07 at 09:11 AM |
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If you bought the chassis and the wishbones from MK at the same time I'd be on the phone right about now kicking up a bit of a fuss!!
If you did (note the 'if' everyone  ) that's shocking, the first Stuart Taylor chassis I bought back in 2000 had similar issues
but not quite as bad as that! - you would of thought things had moved on in Locost building since then though
Unfortunately you need the brackets moving otherwise that's never going to work properly 
Powder coating doesn't look up to much either (I'm assuming it's powder coating?) it has to be said as well
[Edited on 26/9/07 by D Beddows]
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RazMan
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| posted on 26/9/07 at 09:18 AM |
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Its quite usual to gently persuade them into position but if you need anything more than a firm push with your hands then it looks like
something's out of tolerance.
The shims/washers used to centralise everything should be the same id as the bolt
hth
Cheers,
Raz
When thinking outside the box doesn't work any more, it's time to build a new box
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BenB
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| posted on 26/9/07 at 09:22 AM |
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quote:
Originally posted by SyKaTurbo
quote:
Originally posted by BenB
Often the brackets are slightly open IE more like _/ than |_| and when you tighten the bolt it squashes the arms parallel.
It's also not that unusual to need a packing washer (or two) on both sides of the wishbone to pack them out.
Certainly it's important that the arms don't go /_
so when i pack it out do the washers need to be the same overall diameter as the sleeve so i am not gripping the polybush?
You want to be gripping the polybush.
It's a common misconception that the polybush rotates around the central tube. They don't. Or rather, they can do, but they'll wear
out in no-time. The bracket is supposed to grip the polybush which flexes to give the required movement.
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MikeRJ
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| posted on 26/9/07 at 09:25 AM |
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quote:
Originally posted by BenB
You want to be gripping the polybush.
It's a common misconception that the polybush rotates around the central tube. They don't. Or rather, they can do, but they'll wear
out in no-time. The bracket is supposed to grip the polybush which flexes to give the required movement.
Not true. If this were the case the crush tube would be made shorter than the bush, but it's always made longer so the bracket tightens up
against the crush tube without pinching the polybush.
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mistergrumpy
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| posted on 26/9/07 at 09:27 AM |
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He he I knew this was coming! Just to add then, my crush tubes ain't longer than the bushes.
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DIY Si
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| posted on 26/9/07 at 09:32 AM |
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Here we go again! Now, where did I put that popcorn smiley? 
“Let your plans be dark and as impenetratable as night, and when you move, fall like a thunderbolt.”
Sun Tzu, The Art of War
My new blog: http://spritecave.blogspot.co.uk/
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SyKaTurbo
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| posted on 26/9/07 at 09:38 AM |
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I have just spoken to MK and they have insisted that pushing them into place and letting the tightening process pull them in will be ok so we will
wait and see!!
quote:
Originally posted by D Beddows
Powder coating doesn't look up to much either (I'm assuming it's powder coating?) it has to be said as well
the chassis isnt powder coated. it is brush painted. after weighing up the cost of a tin of hammerite against powder coating it didnt make sense for
the parts that are going to get excessive stone chipping!!
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BenB
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| posted on 26/9/07 at 09:43 AM |
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It's complicated re the crush tubes eh?
I know the logic is that hard plastics will be able to rotate around a crush tube (therefore you want a crush tube slightly longer than the bush) but
if the rotation is free and without restriction why are you advised to not tighten the bolts up until the car is on the ground and weight-bearing?
That would suggest the bush is also clamped at a neutral setting and the resiliance of the bush to twisting is used....
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welderman
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| posted on 26/9/07 at 09:49 AM |
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just give them a whack with the hammer, will be ok
Thank's, Joe
I don't stalk people
http://www.locostbuilders.co.uk/forum/23/viewthread.php?tid=172301
Back on with the Fisher Fury R1
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BenB
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| posted on 26/9/07 at 10:01 AM |
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I've e-mailed Polybush. Hopefully they'll be able to put this question to bed once and for all....
Now, which are better, BECs or CECs?
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Ivan
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| posted on 26/9/07 at 10:02 AM |
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The tight fit in the brackets looks like a bad design to me when they could be made to fit comfotably in the brackets which would give you some scope
to adjust Castor by a degree or two by moving the upper and lower bones backwards and forwards, and then use washers or spacers to pinch the crush
tubes.
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D Beddows
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| posted on 26/9/07 at 10:37 AM |
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From personal experience I've found that the 'whack with a big hammer' approach will get the wishbones in and is great if you
don't want your suspension to move up and down a lot or in a predictable manner....... and you wonder why people post questions asking why
Caterhams handle better than Locosts!
I'd seriously consider getting it sorted out properly........ MKs solution is, with the greatest respect, complete cr*p in a 'I
can't be bothered, please go away' stylee - they'll be telling you next that 'they're all like that mate'
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AndyH
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| posted on 26/9/07 at 10:57 AM |
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For what its worth, Beddows is spot on.
Suspension has to fit properly to work properly, end of.
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Bluemoon
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| posted on 26/9/07 at 11:01 AM |
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My experience of putting them on the MK is that you will need to push pull the bones by hand to get them in. You shouldn't need a hammer!
I would not get to bothered about it so long as they don't bind once bolted up, with washers to take up any space in the brackets. You have to
remember that even though they are jigged the wishbone will distort when welded, and this is why they don't quite fit...
Beddows: Not sure I agree so long as nothing binds, maybe for race use yes, but you would then go for spherical bearings, lots of adjustment and you
then get all the trouble they have with them wearing out etc. Also how can you possibly weld a wishbone without 2-5mm of distortion, I guess you could
braise them?
Dan
[Edited on 26/9/07 by Bluemoon]
[Edited on 26/9/07 by Bluemoon]
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D Beddows
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| posted on 26/9/07 at 11:35 AM |
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Thing is though they probably will bind slightly to a differing degree at different points of travel.... personal experience again I'm afraid
!
Ok, I'll admit if you hadn't driven a properly set up 7 with suspension that worked as it should then you'd probably be non the
wiser and think it was a great handling car. Why not do the job properly though and actualy have a great handling car? 
There will be loads of people with suspension like this and I bet some of them have bought expensive hi spec dampers as well.... which would have been
a bit of a waste of money if you think about it.....
I'm not having a go at MK in particular because I know they're not the only offender but if some Locost type chassis manufacturers can
produce a chassis with brackets the wishbones fit into without the use of a big hammer why shouldn't everyone? 
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MikeRJ
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| posted on 26/9/07 at 12:10 PM |
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quote:
Originally posted by BenB
It's complicated re the crush tubes eh?
I know the logic is that hard plastics will be able to rotate around a crush tube (therefore you want a crush tube slightly longer than the bush) but
if the rotation is free and without restriction why are you advised to not tighten the bolts up until the car is on the ground and weight-bearing?
This is true for only for metalastic bushes to ensure the rubber is not stressed in the static suspension position, which would otherwise overstress
the rubber on full bump.
I look at it like this: if the chassis bracket is designed to pinch up the sides of the polybush, the only part of the polybush that will be able to
distort to any degree during suspension movement will be the thin top hat section outside of the bush housing . The bush material inside the housing
is held very tightly by the bush tube itself, so would be unable to deform by twisting. This would put enormous shear forces on the bush.
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John.Taylor
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| posted on 26/9/07 at 12:26 PM |
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My MK brackets and wishbones weren't quite as bad as that but I had to bend/pack them with washers none the less.
I've been over to MK approximately 10 times and not once have I been given the impression that they are a 'precision' engineers.
Take for example their modification of my steering shaft that I pulled out of a scrap yard the same day (mine had power steering). They simply cut it
down with a chop saw and welded it back up with no preparation to either surface, just welding through all the grease, mud and rust that had build up
over 24 years and 163,000 miles.
Also, one of the diagonal tubes on my chassis in the engine bay is only attached at one end - If this was missed during manufacture, quality control
and powdercoating, what else has potentially been missed?
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russbost
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| posted on 26/9/07 at 12:27 PM |
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What Mike RJ said is correct, metallastic bushes should be tightened only once in their weight bearing position. A poly bush will not cope with shear
forces it will simply tear itself to bits in a very short time (like about 10 miles). They are most definitely designed to rotate about the
crush tube, hece the crush tube is longer than the outer tube + bushes.
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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ned
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| posted on 26/9/07 at 12:35 PM |
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If you are going to make these wishbones fit rather than getting the brackets moved I would suggest you remove the polybushes and grind down the outer
edges of hte wishbone tubes until the bushes and wishbone fits the brackets properly, then use large/penny washer to space out the slack on the inner
edges. At least this way, assuming nothing's twisted the suspension shouldn't bind up on you and should fit correctly even if not how it
should have done from the factory.
As rightly said above don't just hammer it together as something will be at the wrong angle and the suspension will be compromised in some way
leading to imperfections in the handling.
Ned.
beware, I've got yellow skin
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