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Ball joint trubs....
scoop - 5/6/08 at 09:51 PM

The maxi ball joints im using dont go far enough through the sierra uprights to get any thread through the nylock and ive still got to fix the cycle wing brackets on it yet! Ive cleaned both so no dirt or paint getting in the way.
Any ideas gents?

COREdevelopments - 5/6/08 at 09:58 PM

you need to have the tapered hole reamed out to fit the maxi ball joint.

Rob

scoop - 5/6/08 at 10:00 PM

I always like the sound of a good reaming
Is that something i can do with a dremmel or is that a job for engineer and a lathe?

jambojeef - 5/6/08 at 10:14 PM

Dont dremel it!!!

You need to get it done in a machine shop or it wont tighten properly - pretty important that bit too!

scoop - 5/6/08 at 10:20 PM

I wont touch it with a dremmel then
Cheers, a little run out in the morning then.

owelly - 5/6/08 at 10:28 PM

You could hand ream it. But buying a reamer just to do the two holes would be a waste of pennies.

jabs - 6/6/08 at 06:36 AM

I have just modified the taper on the Sierra uprights, to match the maxi ball joints, and I must say it was quite easy. I used the tapered reamer from Axminster and it worked a treat. The first one I just reamed until the ball joint fitted correctly, this took quite a while as there is a lot of metal to remove. The second I drilled with a 16mm drill first, as the minimum size of the ball joint taper is 16mm, this was obviously a lot easier and I had it done within 5 minutes.

Tools from www.axminster.co.uk

19mm tapered reamer part number 810033 - £2.94 + vat
16mm drill part number 410029 - £5.18 + vat

MikeRJ - 6/6/08 at 08:02 AM

quote:
Originally posted by jabsThe second I drilled with a 16mm drill first, as the minimum size of the ball joint taper is 16mm, this was obviously a lot easier and I had it done within 5 minutes.


This sounds like a very bad idea. If the minimum diameter of you tapered hole is the same size at the minimum diameter of the taper, you won't be able to get the taper tight enough in the hole before the nut runs out of threads. The taper on the ball joint should never be sticking out past the end of the hole.

The reamer has been mentioned on here several times, but is designed for making holes larger on sheet metal rather than for machining tapered holes. Has anyone confirmed that by some stroke of luck it does have the correct taper for maxi/cortina ball joints?

owelly - 6/6/08 at 08:44 AM

quote:

The reamer has been mentioned on here several times, but is designed for making holes larger on sheet metal rather than for machining tapered holes. Has anyone confirmed that by some stroke of luck it does have the correct taper for maxi/cortina ball joints?

Not true! Reamers are not for enlarging holes in sheet metal. They are for final sizing of holes. Tapered reamers are also not for enlarging holes in sheet metal. They are for creating tapered holes in stuff!
The fact that you can use tapered reamers for enlarging holes in sheet metal is just a handy by-product of having a tapered reamer in your toolbox rather than the right sized hole in your sheet metal!!!

scoop - 6/6/08 at 01:03 PM

Easy guys. I knew this job was well above my head so i took the whole lot to my local, friendly, one man band and cheap engineer and left it with him. Ready next wednesday

MikeRJ - 6/6/08 at 06:05 PM

quote:
Originally posted by owelly

Not true! Reamers are not for enlarging holes in sheet metal. They are for final sizing of holes. Tapered reamers are also not for enlarging holes in sheet metal. They are for creating tapered holes in stuff!


Proper engineering taper reamers certainly are, but the cheapy that Axminster sell is purely designed for sheet metal work (have you actually looked at it?). The fact that they don't even mention the taper angle is a bit of a give-away, and the fact that it costs a few quid rather than £20+ is also another hint. I don't think I've ever seen a proper taper reamer with a built in handle either, they nearly always have either a square drive for a tap holder or a round shank for mounting in a chuck.

I've had a very simmilar one for years (came from Tandy aka Radio Shack) and it's perfect for making front panels of electronic equipment where you want to mount switches, potentiometers etc. but is much happier cutting alloy than steel.

If the Axminster reamer gives the correct taper for maxi ball joints and is hard enough to cut the forged steel uprights that's down to pure luck rather than design!

BTW, Maplin sell a simmilar one as well, though wether it happens to be Maxi balljoint sized I couldn't say.


[Edited on 6/6/08 by MikeRJ]

scoop - 15/6/08 at 07:22 PM

Just got my uprights back from the engineer. He lost me explaining what he had had to do to get everything correct. It must have taken him hours and was embarrased by what he charged me.
He was amazed and horrified to hear that people were strapping the uprght into a vice and just pushing a reamer into it. He even made me the correct thickness castle nuts to accomodate the cycle wing brackets. What a bloke