Hi Ralph - it was only 55 mins for the long hole; the short hole took about 25 mins. The medium hole, today, took 30 mins, partly because I'd a better idea what I was doing & what drill bit noises I could safely ignore, and partly because I had a helper to squirt the oil for me, so I didn't have to keep walking around the job. That saved some time... Oh, that and the fact the drill bit, bless it, managed the first 120mm in a single cut. I was so proud...
As for the video soundtrack... it had to be Zorba, the only problem is, the film really ought to be getting faster & faster to match the tempo, but then it would have been too long & boring... As it was, I chopped the middle of the track out, which is, I think, why it got past the content ID censors.
So....... on with today's installment. I only had the middle-length hole (a mere 342mm) to do today. Here's everything set up to begin cutting:
Today, the drill still rattled the floor, but it cut like a beauty. The "customer" (Dad) appeared at a suitable point in the process to help out with the oil squirting job too, so that saved a bunch of time, it meant I could run the drill out, he sprayed it with WD40, run back in, rinse & repeat. It also helped that the drill was easily cutting 20mm, even at the deepest point, before it clogged up. So that sped things along nicely. As a result, a mere 30 minutes later, the full depth is reached:
And, for the pervs amongst us, here's a rather rude animation of those two pictures (click the image for a link to the big 350kb version):
To give you an idea of how deep the longest hole is, here's the drill bit positioned as if at the bottom of the long hole:
As you can see, the drill bit is actually a fair bit longer than it needed to be... which simply adds complexity and reduces rigidity. At some point in the future, I'll try the £5 eBay drill (500mm flutes instead of 600mm) in one of my leftover ali bits. If that one tracks true, then it'll be a lot easier to use than the 600mm version.
Aaaanyway, I'm putting off the next bit....
I had to know if the hole was accurate. There's no getting away from it, I need to know before I carry out the next machining operations.... So, the mill is re-set to normal, trammed back in (normally, this takes me
forever - but tonight, with Dad watching, I managed it in 5 minutes flat
), lobbed the sump back on the table, dialled it in straight, and found the edges; loaded up the small chuck & a drill bit, cranked the table over to where I calculated the end of the hole to be; back away 3mm in the X axis (I didn't want to land smack bang on the tip of the hole, after all), and...
and....
and....
are you on the edge of your chair yet?....
...
SMACK BANG ON TARGET!
This photo didn't come out quite as well as I hoped it would; there's a bright light being shone down the end of the long hole, and that's my test hole. But it just looks like I photoshopped a white circle into the pit. Ah well...
So, on that happy note, I decided to call it a night & come do this write up. So, to quote a program I often watch on Discovery - now you know, how it's made.
