Ive looked through all the old threads and looked through other websites and not managed to find a solid solution to the problem of tapers in the sierra stub axle and insert. What im looking for is the taper of the maxi ball joint and the taper of the transit drag link end. Ive asked Luego and MK and they 'claim' they dont know so that really didnt help.

help please.....

If you look on the files section of the Yahoo Locost list you'll find a drawing i did in PDF format of the Cortina upright, this shows the taper angles for the maxi (bottom) and the transit (top) ball joint.

Kind regards,

Darren

Seem to remeber on a car is born he used a SEVEN degree tapered drill bit to open up the holes a smiggin
He was using Sierra bits???
Anyone else care to confirm or correct????

I was going to say 7.5 degrees but I'm sure somewhere between the two would be fine. I had mine done at a place in West Drayton (behind SpeedShack) - cost me a drink.

Chris

Got to disagree here guys....

Yes, the actual figure is between 7 and 7.5 degrees, BUT close will NOT do.....tapers have to match pretty damn accurately....but they will with the correct reamer....most motor industry tapers are either 1 in 6 or 1 in 8, with 1 in 8 (I.E 1/8" per inch) works out at 7.125016 degrees to 6 DP....

If the taper is not accurate it will only seat at one end causing high contact stresses (Hertzian IIRC), or creep which will cause loseness and movement......

Bottom line....tapers must fit well...if any rock can be felt it is not close enough.

Seem to remember on a car is born he used a SEVEN degree tapered drill bit to open up the holes a smiggin
He was using Sierra bits???
Anyone else care to confirm or correct????

This may be exactly what you are looking for - or a total load of b*ll*cks
Rescued attachment Taper.GIF

I very roughly calculated the taper of a cortina and sierra at the start of my build, by measuring entry and exit hole dia on the hubs, and the distance between them. A bit of trig worked out approx angles.


I thought it was 2.5 and 4 degrees - but could have been 4.5 and 6 - point is they are quite different.

Make up two card templates, scaled up, and you will see that with that kind or error, there is only a tiny point of contact between the two mating sufaces. As alanB has inferred, looks like a guaranteed shear point to me.

atb

steve

[Edited on 11/7/03 by stephen_gusterson]

I say again, look at my cortina drawing on teh yahoo site and you'll see the drawing i made of the tapers in the upright as measured by a CMM machine.

No need to guess when you have 50k's worth of measuring machine to do it for you.

Kind regards,

Darren

Sorry darren i cant find it on the yahoo lists including locost, locost_uk, locost oz, locost theory. Nor can i find it on the locost mirror/file server site. I can find some dwg files but they dont work with my system(AutoCAD 2000i).

Any chance you can post that file in pdf on this site?

cheers
Fin

Hi,

Send me an email offlist to remind me and i'll send it to you direct.

Darren@gtstuning.co.uk

Kind regards,

Darren

Darren

Are you able to cut these tapers? I'm a bit worried about mine now (we didn't do it particularly acurately!!)

Chris

Yeah we can probably cut them, i'll ask my machinist and let you know.

Kind regards,

Darren

I have no idea what this conversation is about but it seems serious, and that worries me.

do I need to know what this is about?

blueshift:

quote:

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do I need to know what this is about?

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quote:

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Originally posted by Alan B
Yes, the actual figure is between 7 and 7.5 degrees, ... most motor industry tapers are either 1 in 6 or 1 in 8, with 1 in 8 (I.E 1/8" per inch) works out at 7.125016 degrees to 6 DP....

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One problem, that's a transit TRE, not a transit drag link (the M20 thread rather than M18 is the giveaway).

Kingr

The drag link and the cortina/maxi balljoints have the same taper as shown by darrens drawing. If i remember my calculations they were about 7.06deg so a 7deg taper should be the one to go for, cheers darren

quote:

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Originally posted by kingr
One problem, that's a transit TRE, not a transit drag link (the M20 thread rather than M18 is the giveaway).

Kingr

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It's a coupling used on the older steering box systems from the mk1 and 2 transits before they went over to rack and pinion steering. They were handed with a left and right hand thread and only the right hand threaded one is used for both sides on the locost.

yours, Pete.

its a system where there isnt a rack, just a bar across between the steering arms on the hubs. A steering box then has an arm that comes down from it that 'drags' the bar left to right, moving the wheels with it.

thats my understanding - i think mk1 cortinas had it.

atb

steve

Much the same as a VW Beetle then!
No not the new one!

quote:

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Originally posted by Peteff
It's a coupling used on the older steering box systems from the mk1 and 2 transits before they went over to rack and pinion steering. They were handed with a left and right hand thread and only the right hand threaded one is used for both sides on the locost.

yours, Pete.

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quote:

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Originally posted by Stephen
its a system where there isnt a rack, just a bar across between the steering arms on the hubs. A steering box then has an arm that comes down from it that 'drags' the bar left to right, moving the wheels with it.

thats my understanding - i think mk1 cortinas had it.

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