Hi Guys,

Stupid question, how do you actually test a radius with a ball?

So assuming it has to have a 2.5mm radius.....?

Cheers,
Andy

=5mm ball

But I suspect its an extremal radius so need to use a un-ball

Really though ones that small are about bluntness in most cases

Picture?

so how do they test an external radius?

Un balls
http://www.cromwell.co.uk/KEN5180820K

The small radius is tested with a small feeler guage device, the balls (for there are 2) is to see if the edge is contactable, if it is the small feeler guage type tool is used to asses wether the edge is smaller or larger than the required radius
For the dash padded edge can be 5mm radius, an un padded edge has to be 19mm radius.
A common mistake is to make the radius to small for instance a19mm radius is half a pipe 38mm in diameter.
Anything smaller than the minimum radius which I think is 2.5mm could require blunting.
You could go over the whole car blunting washer edges and nuts, studs etc but in the real world nut covers and edge trim will suffice.
There are diagrams in the IVA manual showing the testing proceedures with the balls, half a ball on a stick replicating your head or your knee.

[Edited on 2/9/12 by snapper]

I just took a piece of aluminium, drilled a 5mm hole in it and cut it in to 120deg sections and used that. As already said, if the edge can be contacted by 'the ball' then check it with the tool. Worked fine for me

If you get a chance to watch 'a car is born' one of the later episodes show the car going through SVA, and demonstrating the process.