I was watching and didn't understand. With subtitles it's maybe better. Will restart.

Very accurate / precise machining for a backyard sharpening operation. Well done!

Да, но даже микрометр не помог, что бы работали обе режущие части. Работает только одна. Спираль стружки, выходит с одной стороны.

"So i had to show them how to sharpen dull or broken drill bits, of which they had many." Part of it is a failure to select and use correct spindle rates for drill material / workpiece material combinations (explains the prevalence of blunt drills wherever you go) and only part of it is an inability to sharpen drills... One other thing is that "other trades" are permitted access to grinders that ought to be used exclusively for drill/toolbit sharpening. So, you pitch up at the pedestal / floor grinder and it's got grooves in it, the corners have huge radii on them. No good for sharpening or point thinning/relieving... So you say bugger it, and pop the drill back in the rack... I used to carry a diamond dresser in my pocket for a little light wheel dressing. (never lend them, by the way, if a guy hasn't got one, there's a likelihood he'll destroy yours, and not even realize...) Avoid heavy dressing of the workshop wheel with the Huntingdon dresser until Friday, the day you throw your overalls into the laundry bin... Unless you're happy with a liberal coating of aluminium oxide dust, long term...

樹脂にはローソク研ぎで加工すると割れにくく綺麗に空くと聞いたことがあります。 まだ未確認ですが参考にしてください

"the drilling of sheet metal" Well... Making holes sheet metal with a conventional two flute drill was never considered a clever thing to do, and a common piece of advice for drilling in general is "You can hold the workpiece by hand if you can break the drill bit by hand... A good basic rule... The problem with drilling sheet metal with a twist drill is that the point penetrates the material before the lip corner enters the material, so there's nothing supporting and centralising the drill bit. That's why you get oddly shaped holes, when drilling sheet metal. (that, and badly off hand sharpened drill bits... Anyway... If a more suitable tool is not available... (Rotabroach, Rotobor, hole saw, punch laser, other) Try "rag drilling" set up your drilling machine correctly to position the hole where you want it, and start drilling, but don't penetrate, leave a dimple, then... get some squares of rag. (Denim's good ) a bit bigger than the hole size, and interpose them between the drill bit and the workpiece, then drill. The rag will fill the drill clearance, offering 1) radial support to the drill and 2) resistance to the drill's "pulling in" to the workpiece. On that last issue... use the drilling machine's quill clamp as a brake, to avoid "pulling in" There's always a bit of backlash in the quill's rack and pinion drive. I have used, in the absence of denim, emery cloth, which works, but doesn't do drill bits any favours... No one else remember "rag drilling"?

@@robertlawson8572 my whole point was based on the size of the bit and piece of metal being drilled in the video. I worked as a toolmaker for 40 years managing build and stamping operations. we made shims for punches and die sections by the thousands each year. you can avoid the accident by using safe measures. a clamp is a good safety measure. even a step drill is much better for drilling clean holes in sheet metal but when it grabs the work piece and you are holding it by hand lookout! Fingers don't grow back, just wanted to bring to peoples attention when i see a potential accident about to happen. remember there are lots of people that see a youtube video and think that it's a best practice to use when they go to do something. just my 2 cents.

@@user-ym4sf2er2p Sorry, pal, you seem to have bit... I just added a basic rule of drilling to your statement that clamping is necessary... Now it's lost in the noise. So... to recap, If you can break the drill by hand, you can hold the workpiece by hand... (If you must) It really sets very low limits on the drill size. We all have our old war stories about drilling incidents... I forgot to mention at the time about modifying the drill's rake to zero, or close to zero, to avoid sheet metal pulling up... Works well on spring steel, too... Same as putting a brass lip on a drill...

@@user-ym4sf2er2p I did respond earlier, my post seems to have gone... I hate the use of two flute drills for SMW, clamps or no clamps. We did have "Brad Rad" step drills for lightening holes in A/C work, in the seventies, but, though the zero rake was good for avoidance of the workpiece rising, the zero rake was not good for light alloys. Of course, sometimes it's necessary to drill thin stuff, or even stuff that's thin and hard, like spring steel sections for attachment screws... (punching introduces stresses that lead to failure, plus drills are easier to sharpen than punches... Then, I used either a combination centre bit (Are they still "Slocombe" bits over your way? ) Which have close to zero rake, and point thinned them for easy penetration, or a jobber bit with modified rake and point thinning. Rag drilling, as I described in the "lost post" can work well, saves drill modification... Still hate drilling sheet metal work, except in desperation...

They did dip the drills into water periodically to keep it cool after each grinding operation. It was shown near the beginning.

I bought it on Amazon. amzn.to/3y9n7SJ

Thanks

I'm explaining with subtitles.

If there is no angle, contact occurs through rotation. This cannot be explained in words. You can understand this by actually sharpening the drill with the angle set to zero.

@@jisakukobo I understand that contact occurs through rotation when there is no back angle but it's at the back of the edge which doesn't make any difference for actually cutting the metal. If you want to drill on both clockwise and anticlockwise then it make sense to give it a second angle at the back otherwise it doesn't do anything for drilling.

"you know your drill is sharp is when you drill the whole you get long unbroken spirals." Well... You won't with hard brass, or with cast iron. And in any case long swarf is at best a PITA, at worst, dangerous. That's why we "woodpecker" to avoid long swarf (other ways of avoiding long swarf are available...) That was something we were taught in the 60s. "Long, continuous swarf is a sign you've got the right speed, feed and tool geometry" We used to compete to produce the longest piece of swarf. One day, a guy where I worked had a long spiral of swarf snaking from his lathe across an aisle, and another guy, not noticing, tripped on it and cut his ankle badly... Not long afterwards, coincidentally, we were being taught to produce short chips, which are easily managed, don't weave themselves into machine handles, clamps, etc... In respect of using progressively larger drills to make big holes, the point was made to me, in the early seventies, that that was an inefficient way of working (though it may be necessitated by low powered machinery) Drilling a 2" hole through solid, or with a small pilot, about web thickness, maybe a little less, is quicker than continually swapping bits. The guy that told me that made the valid point that if the bigger drills were not intended to drill through solid, they'd not "cut to centre" Core bits for casting work don't "cut to centre" because the hole was sand cored to save you that...

Спасибо 👍

タイトルいい加減につけてました。 全部で6つのドリルの紹介でした。 0:00 【ドリル研磨の概要とグラインダーの準備】 4:32 【直線研ぎの方法】 9:18 【治具を使った直線研ぎの方法】 10:40 【円錐研ぎの方法】 13:55 【ローソク研ぎの方法】 15:42 【木工ドリル研ぎの方法】 16:45 【下穴ドリル研ぎの方法】

Thanks

​@@jisakukobo👍👍👍

Автор японец у него заточка сверл по Японский! Нано!!! Технологии!

@@vasjpupkin4420 А что у японцев сверла какие-то не такие как у остального мира? Или сделаны из нано материалов?

​@@vasjpupkin4420Нанотехнологии😂👍

Ну Вы монстр👹пачками точили. По мне так, чем меньше зависит заточка от чела, тем лучше.

@@user-fx7ic1tw6d В тех условия которых работал я, никакая автоматика не угадывалась и близко, полуавтоматические линии серийных деталей, на каждой по 25 металлообрабатывающих всякой разности станков, сверловочных операций было море, соответственно и сверел была гора. То есть если я бы няньчился с каждым сверлышком, то никогда б не делал норму, при этом качество требовалось в соответствии техпроцесу...

Because that’s not gonna work. You should start at the shallower angle at the cutting edge and move the tip of the drill bit upwards as you turn it.

I didn't know how to sharpen a drill, so I asked the drill manufacturer to explain it to me. Do you know the correct way to sharpen a drill? Words that are perfect for you. True ignorance does not know that it is ignorant.

Спасибо за ваш комментарий. Пожалуйста, не стесняйтесь комментировать.

Так он и так на глаз всё точит. 😉 А если глаз кривой или руки не из того места? 😜🤣 В любом случае принцип то нужно знать. 😉

да все понятно, прекрасная напоминалка))

アレ高いですからね 形状的に下手にいじると径が変わってしまうので難しいと思いますが考えてみます

​😅😅😅😅 1:00 1:00 1:00 q9@@jisakukobo1:00

это как? просвети!

очень интересно спиралью, а то задолбала эта стружка