https://www.youtube.com/watch?v=-EbrLKXp-yU
Drilling perfectly centerd holes in round stock, using my homemade milling machine.
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https://www.youtube.com/watch?v=-EbrLKXp-yU
Drilling perfectly centerd holes in round stock, using my homemade milling machine.
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Thanks engineer steve! We've added your Round Stock Center Drilling Setup to our Drilling and Drill Presses category,
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"Perfect" is a rather high standard. Indicating center, as you demonstrate, is probably the best that can be done but there are uncontrolled errors.
The stock will never be perfectly round, the spindle will always have runout. The center drill will never drill exactly on center so the drill, even if perfect, will not drill on center.
As you point out, the machine will deflect while drilling which also throws off "perfect."
Ataining the best possible accuracy for a given machine is the best anyone can do. In most cases, this is damn good.
Rick
Even if you get everything aligned down to the atomic level, there is still no "perfection". The electrons become probability clouds and the very fact of you observing alters the outcome.
You guys are absolutely right but I don't think that 'perfect' has a fully defined definition. When you say something fits perfectly it generally means that it is perfect for your standards, I guess that's why tolerances have been invented to give a solid definition when it comes to size. I appreciate your thoughts
The only "perfects" I can think of are limited to events defined by humans as opposed to events in which nature has a hand or subjective evaluations are considered.
You can bowl a perfect game but only because humans have defined a finite scoring system and strikes are immediately determinable. Having your interior decorator decide the perfect color to paint a room is impossible.
The easiest way to drill a hole in the centre of round stock, if it's small enough, put it in the drill chuck and clamp a drill/centre dill in the vice.
That sure will work but will not be as accurate, if the drill chuck doesn't perfectly line up with the vice or chuck on the table, you will force it out of precision. The method in the video can be adjusted down to 0.01 mm (0.4 Thou) or beyond, depending on your setup.
Obviously, if the work is spinning and you bring it down onto a centre drill it will centre itself. It's no diffent from drilling a hole in round stock on a lathe with a centre drill in the tailstock.Quote:
Originally Posted by engineer steve
Obviously the centre drill has to be centred, but it's not that critical.
I have no need to do it thisvway because I have a lathe, but I did it thisvway for many years before I bought a lathe.
Still, if your happy doing it your way, good luck to you
There are many ways of doing things, accepting 'your' way as the best, most accurate and onlynway of doing things is a fool's errand.
Here is another way:
1) mount the round stock in the 3 jaw chuck with at least 1/2” sticking out. Do not clamp the chuck to the table yet.
2) slide the chuck around until the stock slides into the drill chuck
3) tighten the drill chuck while helping the 3 jaw slide into alignment
4) clamp the 3 jaw to the table
5) loosen the drill chuck and mount the spotting drill in it
You do pick up error in the drill chuck plus spindle runout.
I hope all see how this idea evolved from many of the comments in this thread. All of us are smarter than any one of us.
Rick
The only "perfect" I know on Earth is in math. 1 +1 perfectly equals two. "Perfect", like beauty, is in the eye of the beholder. The same goes for the term "accurate."Quote:
Originally Posted by engineer steve
Rick
Even in math, though, perfection can be defined, but not achieved.
A (perfect) circle is defined as the locus of points equidistant from a central point. Yet no one has ever constructed a perfect circle.
Irrational numbers are another case. There are numerous infinite series for pi but, even after millions of digits, we don't have an exact value (and never will).
One must be careful. Mathematicians are very careless in their choice of names for mathematical entities. As an example, the solution to the equation:
x² + 1 = 0
was termed an "imaginary" number. There's nothing imaginary about it and it's used widely in many real world applications of math.
They also decided to call numbers equal to their aliquot sums "perfect", e.g. 6 = 1 + 2 + 3. While it's an interesting and fairly rare property, there's nothing "perfect" about it, other than its poorly chosen name.
I bought a wiggler. It's basically the same thing, with the added benefit of the dial remaining in the same orientation so you can see it. Works good.Quote:
Originally Posted by engineer steve
So many people going on and on and on about perfect. Give it a rest, bloody ridiculous!
Have you considered unsubscribing from this thread?Quote:
Originally Posted by th62
Rick
I'm interested in the topic, not the definition of perfect. So no, but, since you're clearly more interested in the definition of perfect, why not start your own thread on perfect, rather than try to derail this one?
The internet in a nutshell; 50% cat videos and 50% pedants desperately waiting for an opportunity to correct someone. Correcting colloquialisms and hyperbole as if they were literal statements not a constructive hobby.Quote:
Originally Posted by th62
Some people are just incapable of giving somebody a pat on the back and saying "well done." Gotta tear them down and make them regret participating in the first place.
B- for initiative. Need to study "TIR." Your mounting "stub" is not centered. Therefore your centering efforts will all have the error of your mount. I posit that you saw a version of this in a catalog or a YouTube, and said "saw it on the Tube, I can do that."
Do it again but this time use a piece of stock four times bigger diameter. Get a combination square and layout the crossing lines to find center at the intersection. Prick the intersection, punch the intersection, drill the intersection. Now you've laid out and performed a center drill that, if you practice, should be accurate to around 3 to 5 thousandths of an inch. No need for new gizmo, you've mastered the skill. Cheers.
Me I'm lazy I usually just chuck things up in the lathe and spin them running a center drill into them. If I am extremely worried about being absolutely concentric with the OD then I'll toss on the 4 jaw and use a magnetic base dial indicator to center it up, when the needle doesn't move more than half a mark in either direction it is close enough
That works perfectly (oops I said it again) but not everyone has a lathe, also if you have a bigger part with a round feature that needs 'perfect' center drilling, this method comes in handy. If you need to center a lot of parts it is indeed nice to have a wiggler.
Yep, I never said the method of finding center in a mill or drill wasn't needed. And your method is somewhat easier than X,Y kiss off divide the diameter by 2Quote:
Originally Posted by engineer steve
A dial indicator mounted on a boring head is a must when trying to match up to a previously bored location Chasing zero zero boils down to Occam's razor. You can go half the distance remaining to near infinity and still never find true zero