the malpractice case?
That looks beyond sketchy.
the malpractice case?
That looks beyond sketchy.
Mike Devins' rely reminded me of an occurrance we had when I was working at Midwest Airlines. At that time we had a big gear drive drill press in the sheetmetal shop. One morning before delivering my crew briefing I happened to walk by. Still chucked, was a 1/2 drill bit, bent 90 degrees to the chuck! Never did find out the who what or when, but i was just curious as to HOW!
DanN
I'm much amused at the 44 posts on our stories. This is why my wife calls apexspeed "Racebook".
And there is potential for so much more... waaay more interesting than FV or FA series thread pissing contest
Aaron
...then there was the time I drilled a hole through my thumb. Down through the fingernail and out through the pad. Worse part was what the chuck did to the nail.
Guys, this is not helping. Here I am considering a career change to the machining business!
Nah, keep'em coming, it'll keep me on my toes.
Drilling pedal mount holes in the floor sheet today. I usually hold such big pieces only with my hands -- just slide them under the bit in the press and drill away... But then, today... after Rob's story, I had a vision: What if the bit grabbed as it went in ... and swung the whole 30 inch piece of aluminum sheet like a great huge simitar?!?!!
What if it cut right through my shirt and into my stomach!!!
Intestines and guts and food would be everywhere!!! Ahhhh!! Ohhhh!! Aghhhh! And then I'd pass out...
So I clamped my floor pan solidly in the drill press before drilling today. And it only took maybe one extra minute. Two at most.
And my mission was safe and successful today.
So Racebook ist gut!
Did you hear the one about the Italian machinist who got caught up in his work on a lathe?
He went Wop, Wop, Wop, Wop, Wop..............
How do you drill holes precisely without clamping the work to the d/p table, in a vise etc, assuming they need to be drilled precisely?
Aaron - For precise placement of holes in smaller parts, I use my mini-mill. Also, if you don't clamp the part in the press, you can often end up with triangularly oblong holes.
Depends on what you mean by "precise".
For most work, you can use a spotting punch - some come with a magnifying lens and cross hairs for really close alignment. once the "spot" is in place, use a small center drill to start and open the hole, and then change to a single flute step drill or a piloted counterbore.
Spotting can also be done with a spring loaded "snap" center punch. Very handy.
Or, spot the center, then use actual sheet metal drills to bring it to size. One nice thing about sheet metal drill is that it is almost impossible for them to grab the sheet out of your hands.
If you are only doing a couple of holes then clamping the part securely is always best.
If I'm drilling or countersinking a lot of holes, or doing a lot of parts, I just tighten a clamp on the edge of the table. That serves as a "stop" to prevent the part from rotating. Then you are only positioning the part and holding it down, and the clamp is resisting the torque of the drill press.
I like to use a large Kant-Twist clamp--they have a big square clamping pad that makes a nice stop.
Nathan
This thread is gross. If you are going to try to hold a piece of sheetmetal in the press while drilling holes, at least wear a MIG welding glove on the "clamping" hand!
Matt King
FV19 Citation XTC-41
CenDiv-Milwaukee
KEEP THE KINK!
I have it on the ground with a sheet of plywood behind and stand on that bitch!
Which might be precisely where the racing phrase "Stand on it!" came from... Huh..
I'd be afraid of chasing off prospective participants with much more of this kinda shop reality...
Long Live Ole One-Arm
Lefty
Richard - what do you mean by sheet metal drill? The conical step bit kind?
Re-reading my post I realized the smart-ass-ed-ness I intended didn't really come across...guess that's why the sarcasm smilie was invented...I know how to drill a precise hole and have also drilled a few hand-clamped oblong ones in my time...I should have asked if the 'hand-held' perfunctory perforators on here are drilling lots of un-round holes in stuff
Aaron
Ahhh... I totally missed your humor Aaron.
A sheet metal drill is specially ground on the end to have a center pilot/drilling point, with the most of the end of the flutes recessed so that the flute ODs cut the sheet first. In wood working a similar drill is called a fish bit, but I can't remember what the name is for metal working. The shaping of the space between the center tip and the OD is a bit different that what is shown below, but similar enough to get the idea across. In the past we've actually made most of ours from regular drills by hand-grinding them
Last edited by R. Pare; 04.07.17 at 7:55 PM.
I would call what you are describing a brad point drill.
66 posts and only one picture. Shame on you all
Nice to use since they cut round holes, center on the punch mark and don't grab all the time.
BTW; never hold sheet metal in your hand and drill it with a regular bit. Ask me why I have a nice drill bit shaped scar in my left palm...it was a new bit as well, nice and sharp.
Hand-ground bit for sheet metal:
Last edited by HayesCages; 12.29.12 at 4:50 PM.
Lawrence Hayes
Hayes Cages, LLC
Sagle, ID.
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