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mini ball joint taper
smart51 - 8/11/07 at 12:11 PM

I'm planning a bubble car build using mini uprights. Either I have to use the original iron suspension arms or I have to make my own steel tube wishbones. If I make my own, I'll need to cut tapered holes for the ball joints top and bottom.

What is the taper of a mini ball joint.

What alternatives are there other than OE iron arms or custom made steel?


Marcus - 8/11/07 at 12:23 PM

My Alfa 156 has alloy wishbones - maybe adaptable?


Delinquent - 8/11/07 at 12:29 PM

This isn't going to be much help... but while trawling the net a few weeks back I came across mini uprights made from ally - they are extensively used in hillclimb and lightweight specials for racing (I'm told!) so shouldn't be that hard to come by - certainly worth putting some time into a search to see if they make other parts as well.

[Edited on 8/11/07 by Delinquent]


worX - 8/11/07 at 12:59 PM

I don't think the uprights used by Zcars for their Mini are that dear.?.

Steve


Jimbob - 8/11/07 at 01:18 PM

Kent Auto Developments produce lots of special goodies for minis, might be worth a try

James


britishtrident - 8/11/07 at 02:33 PM

The steel in Mini bottom arms is weldable --- Mini freaks have been making adjustable bottom arms for 40 odd years without problem.


smart51 - 8/11/07 at 03:06 PM

Are the top arms weldable too?


britishtrident - 8/11/07 at 05:58 PM

quote:
Originally posted by smart51
Are the top arms weldable too?



Likely to be the same stuff


minitici - 8/11/07 at 07:11 PM

Mini ball joint taper is a 7 degree included angle.
The ball joint pin can be turned down parallel and a spherical bearing can be used in your suspension arm.


britishtrident - 8/11/07 at 08:55 PM

quote:
Originally posted by minitici
Mini ball joint taper is a 7 degree included angle.
The ball joint pin can be turned down parallel and a spherical bearing can be used in your suspension arm.


?


Minicooper@work - 9/11/07 at 08:49 AM

quote:
Originally posted by britishtrident
quote:
Originally posted by minitici
Mini ball joint taper is a 7 degree included angle.
The ball joint pin can be turned down parallel and a spherical bearing can be used in your suspension arm.


?


Like this but with a single spherical bearing on the top ball joint, the taper is removed on the tapered pin to resemble a bolt shank and then a standard spherical bearind can be fitted to it. Non of this sort of thing would use a top cast arm
This is not my frame belongs to a guy called Gavin Wakely

Cheers
David Rescued attachment Gavin Wakely.jpg
Rescued attachment Gavin Wakely.jpg


MikeRJ - 9/11/07 at 10:27 AM

quote:
Originally posted by Minicooper@work
Like this but with a single spherical bearing on the top ball joint, the taper is removed on the tapered pin to resemble a bolt shank and then a standard spherical bearind can be fitted to it. Non of this sort of thing would use a top cast arm



The ball joints that screw into the mini uprights have the tapered pin on them. If you somehow machined this to a straight pin, you couldn't simply slot it into a spherical bearing in the end of a wishbone as you'd then have two ball joints which would introduce a very significant amount of uncontrolled movement.

If you could machine the pin parallel, with a flange at the bottom it could be put through a straight hole in the end of the wishbone (no spherical joint) but I fear that making the ball joint pin parallel would be vastly more work and making a tapered hole in the end of a wishbone. And you'd have to do it again when you replaced the ball joints.

IMO it would be far easier to get a suitable lump of steel machined (by a machine shop) with the correct taper, and then weld it to the end of the wishbone.


Minicooper@work - 9/11/07 at 10:52 AM

Well all I can say is I've seen it done several times and it seems to work well enough

Cheers
David


Minicooper@work - 9/11/07 at 11:04 AM

Found this picture of what they do with metro uprights in this case on a terrapin, they make an adapter which screws into the normal balljoint cups, this version has no movement in the replacement balljoint all the movement is in the rose joint

But like I said I have seen both ways done to achieve this

Cheers
David Rescued attachment Mini Metro Upright.jpg
Rescued attachment Mini Metro Upright.jpg


JC - 10/11/07 at 08:26 AM

I have 4 bushes with a mini taper reamed into them - they were bought for a previous project from the company that make wishbones for the GTM Libra. You can weld them to the end of wishbones. I also have 2 metro front uprights - these have a 'bolt on' type ball joint that could be used on a lower wishbone. I'm open to offers if these are any good to you. I'm away until Saturday 17th but I'll reply then if you are interested!


smart51 - 10/11/07 at 09:28 AM

quote:
Originally posted by JC
I have 4 bushes with a mini taper reamed into them


U2U sent. Thanks.


MikeRJ - 11/11/07 at 02:53 PM

quote:
Originally posted by Minicooper@work
Found this picture of what they do with metro uprights in this case on a terrapin, they make an adapter which screws into the normal balljoint cups, this version has no movement in the replacement balljoint all the movement is in the rose joint


Right, that makes much more sense. Whatever you have seen, it couldn't have involved two balljoints as it simply would not support to the top of the upright properly. Perhaps the original balljoint in the upright was welded up to fix it one position?


Delinquent - 11/11/07 at 03:57 PM

I thought when they used the spherical bearing option, they cut the ball down to create a pin that the spherical bearing would fit on, rather than the taper?


britishtrident - 12/11/07 at 08:51 PM

quote:
Originally posted by Delinquent
I thought when they used the spherical bearing option, they cut the ball down to create a pin that the spherical bearing would fit on, rather than the taper?


That dosen't make any sense.

Making a fittings up to replace the ball joints is however workable.