Steering Arm Taper

[philthehill]

There is a similar thread on the web and here is the link
http://locostbuilders.co.uk/viewthread. ... 46&pages=1
Note the reference to the reamer from Axminster tools Pt No: RD013066. Having looked at the Axminster Tools web site I think the part number should be 810033.
I see that Chadwick & Trefethen Inc do a proper ball joint taper reamer at 7.15 degrees; but they also do 5.71 and 9.56 degrees.
Looking at the Minor ball joint taper and the Minor steering arm taper they appear to be different but I have not measured to confirm.
Best of luck

[Matt]

I already have a reamer like that axminster one... somewhere

[katy]

I figured out the angle from the measurements that Phil gave: 16 to 1, and it worked out to be 3º 35 min or aprox 3 1/2 º. This is aprox 1/2 of one of the reamers Phil mentioned

I see that Chadwick & Trefethen Inc do a proper ball joint taper reamer at 7.15 degrees; but they also do 5.71 and 9.56 degrees.

Anyone else able to calculate it and come up w/an answer? Either the same or?

[philthehill]

Found the attached table in one of my engineering text books which may be of help. [frame][/frame]

[philthehill]

Matt
Have just done a final check on the angle and it looks like the steering ball joint taper reamer at 7.15 degrees is the one to go for.
How did I come to the conclusion well:
Placed the steering arm taper in the grove of a combination square rule to ensure that the rule was parallel to the centre line of the taper. Then placed another steel rule parallel to the taper and had the intersection of both rules at 0". Then measured the distance between the centre line of the combination rule and edge of the steel rule at 12" and it measured 3/4". Double that to 1 1/2" and referring to the chart above the Included Angle reads 7 deg 09 min. Also checked the Angle with Centre Line with a protractor and it was the same.
Whilst I am happy with the above I would advise that you should carry out your own checks.

[bmcecosse]

Try a steering arm in the ball joint taper of another arm - does it rock?

[philthehill]

unfortunately that will not work as the steering arm taper is bigger than the taper for the track rod end!
The steering arm taper at its smallest is 16.7mm dia and the ball joint hole is 14.6mm dia at its largest.

[Matt]

Phil -

Thanks very much!

I have been a bit busy with a friends transit this weekend and forgot to get the bits out to measure