A couple of days ago, I wrote about putting the table back on my G0704 mill and finding a problem with clearance around the oil tube to the Y-axis ballnut. I concluded by saying, "Will the thinner tube lie lower and flatter in the cutout and be less susceptible to damage? We'll find out." The answer is it didn't. The next morning, I could see that the tube had relaxed to the point where the table was hitting it.
The root cause is that the vertical edge on that
part of the table goes over the oil fitting. The tubing is almost
completely under the slide. It's easy to see when the tube is off.
I pulled the new bent tube and made another one out of a longer piece so I'd have more tube to
play with. After I heated the tube and flared it so it fits the oil
fitting, I stuck the plastic tube from a spray can of air in it, held it
over a heat gun and bent it a little past a right angle (plastic tube
to emulate something like putting sand in a metal tube before you bend
it - to keep the walls from collapsing/kinking). This was definitely a
lower profile bend. I put that in place, but a straight edge sliding
over it still rubbed on the tube. If I held the tube down with a finger
tip, it seemed to clear, so I put a spot of RTV there and then taped it
down with duct tape. It was still too high, so I stacked about 15
pounds of weights on top of it to clamp it as low as it gets. The tube
said RTV takes a full 24 hours to cure, but after about 18, I took off
the weights and tape to look at it.
So I decided to machine away the part of the table that crosses and
could rub on the tube. The idea is to cut away the underside of the table at about a 45 degree
angle - 45 degrees at "eyeball accuracy" is good enough. The table is about 28
inches long, so you see it requires cutting away a fairly large amount
of cast iron. I had thought of doing this before but concluded I'd need a
mill at least the size of the G0704 to do it. A friend suggested an
angle grinder. I simply hadn't thought of that because I just don't have
experience with using a grinder. I bought one months ago for this project
and then used my Sherline mill to do the cutting the grinder was
You know the old saying, "when the only tool you have is a milling machine, every problem looks like a machining problem" (or something approximately like that involving hammers and nails)? When I thought about cutting back that edge at a 45 degree angle or so, I though of using a 45 degree cutter in a milling machine, or a straight cutter with the table on a fixture of some sort. I simply never thought of the angle grinder. Mind you, as I've said about knife making, after a few dozen silversmithing projects, I've come to believe I can do just about anything with a few hand files. I could have done this with hand files and taken a week of labor or a few minutes with an angle grinder. The angle grinder is the way to go!
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