On Dec 17, 12:02 pm, wrote:


OR - do I need to set up the bar in a 4 jaw, centre drill, then put it
in a cylindrical grinder to make sure it is 100% accurate?......

Andrew VK3BFA.

To make a test bar, you need to centre drill it as accurately as
possible. So yes do use the 4 jaw chuck and spend some time getting
it centered. before drilling each end. Using a cylindrical grinder
may make it more accurate, but that depends on how well the grinder
is set up. If the school has a bench center, use it to check the
accurary.


Dan