Rich,
The most available solution is to take it to another machine shop and
have them re-bore the holes in the right spot. This can be easily done
on a manual mill with a single point boring tool and boring head, since
you already have a lead-in hole that is close to true position. A
backyard/garage machinist and Bridgeport can do this. Best to use Dykem
to color the surface, clamp the parts together for best average fit and
carefully scribe the fix. A decent machinist will get it true within
1/32" or better to the scribed arc, since you have a known diameter target.
Grinding out 1/4" x 3/4" will be painfully slow and hard to get
straight/perpendicular. Several good carbide burrs and a 1/4" die
grinder will set you back more than the hour or two of mill time to do
it right.
Grant KZ1W
On 9/7/2015 11:33 AM, Rich Hallman - N7TR wrote:
I had a ¾ inch steel plate made up that will be used to retrofit a HDX589 base
foundation to a HDX572 base. After giving both bases to the machine shop and asking
them to make sure all of the holes are exactly the same location as the base, some of the
holes are 1/8 to ¼ inch off. I had a major issue with this machine shop so I will
not take it back for now.
I wanted to see what others have done to grind out holes in thick steel plate.
I was looking at the Carbide Burr bits and getting a ¾ inch burr bit to see if
that would grid enough from the hole so it would then fit the bases.
The holes are pretty close....so I thought grinding them out would be the best
solution for now.
Any thoughts?
Thanks....Rich
Rich N7TR
ex KI3V, N3AMK, WB3JOV
www.n7tr.com<http://www.n7tr.com>
http://www.qrz.com/db/N7TR
Telnet: dxc.n7tr.com N7TR DXCluster
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