I guess that aside from being a great video, this is something of a test of technical nerdy-ism. If you find this hour long video really interesting, well, you know...
Really cool stuff from Tim Hunkin:
-- I liked the angle driller. Need one.
-- The placement of the magnets near the hole to catch the shavings was really cool.
-- Tim's reluctant admission that it is just better to buy new drill bits (as opposed to sharpening old ones) is good advice.
-- WD-40! Yea!
-- Note: No white "Boffin" coat for Tim. Just "overalls." But as I watched I found myself thinking that he could probably have used an armor plate or at least a Kevlar vest amidst all that flying metal. Perhaps a bit more eye protection too...
-- Fiddley. A useful tech term.
--Swarf: Another useful tech term: the metallic remnants (shavings) of drilling.
-- The digi readout on the milling machine looked really useful.
Finally, I loved the sign that Tim has posted in his workshop:
SMALL HADRON COLLIDER
This is a great video, one that every Ham (especially the mechanically . . . challenged) should see. My Dad, a trained machinist and mechanical engineer (in electronics manufacturing), was something of a fanatic on hole-making technology. I watched many times as he deftly used a bench grinder to hand sharpen even very-small drills, each time getting a lecture on proper relief angles, "rake" angles, and symmetry, all of which he could judge perfectly by eye as he ground. When, as a very-young man during the Second World War, he was trained as a machinist, sharpening machine tools like this by hand and eye was an ordinary mark of competence and the coin of that oily and gritty realm.
ReplyDeleteOne thing I would add to Hunkin's hole-making advice is the *step drill*, a relatively-new (or newly popularized) tool for making holes in sheet metal. In his section on thin materials, Hunkin showed how ragged a hole could be in sheet stock when drilled with an ordinary twist drill. He didn't demonstrate, though, just how dangerous it can be when a drill bit ground with too-sharp a relief angle can grab the metal and screw it up the twist, causing it to spin at pretty-much the same RPM as the drill and hacking everything to pieces it comes in contact with. If your hand was holding the work piece when it did this, there'd be "blood in the marketplace."
Step drills avoid this, in part, because there's no twist to them and they cut entirely on the circumference of each step rather than from the center-out as a twist drill does. They are *much* safer to use on sheet metal, and they make *very* clean holes. Harbor Fright and all the big-box stores have them. They're inexpensive, and come in a variety of sizes (usually in sets <$20).
Agree 100%, first time I tried a step drill I was amazed at the improvement in drilling and safety.
DeleteI forgot to say that I won't be saying anything about the WD-40 reference.
ReplyDeleteThat's big of you Todd. We thank you for that. 73 Bill
Delete