How I Spent My Sunday

I've been saying throughout my big project of converting my Grizzly G0704 milling machine to computer control that "every part is a puzzle".  That has taken on whole new meanings as I try to figure out how to add the powered oiling system that Hoss uses on the DVD I bought.  Now it's not a part I'm making that's the puzzle, it's the modification itself.  Hoss chose to put the oiling system on his publicly readable webpage, under the projects tab - conveniently here. 

I wrote about some of the work I was doing and what was coming soon behind it just a few days ago, and said, "It looks like the biggest task is to cut some channels on the surface of the cross slide that holds the table for the oil to flow between them.".   Since I successfully milled out the area where the ballnut for the X-axis goes on my micro mill, the channels aren't looking so scary right now. 

The cross slide in place on my Sherline mill for a test fit of the ballnut.  Milling the cast iron was tedious and the chips it produces are nasty, but it wasn't really difficult and I never heard the motors bogging down or anything.  (On the other hand, I have a better appreciation for where the saying "a cast iron bitch" comes from!)

This makes the long oil channels seem less scary, and the scary part becomes something that only shows up briefly in the top left video, "Oiling system passages".  Hoss marks off a spot to drill, looking freehand, and then drills a 1/8" diameter hole 4" deep into the cross slide from the one end.  Take a look at this picture I posted a few days ago:

While the hole doesn't go in the end closest to the camera in this picture, look at the marked lines on the right dovetail.  Looks like crosshairs or a target indicator.  Hoss drills the hole 4" into that piece, parallel to the table. 

One of the things I learned very early in my hobby machining is that drill bits can wander and not produce straight holes.  This is why standard drill bit sets have shorter bits for smaller diameters and longer bits for larger diameters.  The ratio of length to diameter is set to reduce the chance of wandering.  Most 1/8" bits have a fluted length of around an inch to 1 1/2.  This one needs over 4" fluted length.  I needed to order a 1/4" ball end cutter for the channels (coulda sworn I had one), so I ordered an exotic drill bit to drill the long hole, too.

As a result, I spent a lot of today trying to figure how to drill this with the best chance of success; going through the shop trying to find something I could rig up to hold the cross slide perfectly vertical for the drill press - or use the G0704 itself.  I could try to do it like Hoss does and just chuck up a long drill bit in my cordless drill and start drilling, or I could try to set the cross slide up with some sort of fixture that improves my chances.  And I swapped messages with Hoss.  He said, "you're over engineering this.  Just drill the hole".  Yeah, I can tend to do that.