How To Regrind Drill Bits Using a Quorn Tool & Cutter Grinder
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- čas přidán 29. 12. 2022
- In this video we demonstrate the process of precision drill grinding with conical flank relief on a shop-made Quorn tool and cutter grinder.
The kit to build your own Quorn tool and cutter grinder can be purchased here: www.hemingwaykits.com/HK260X
References:
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www.modelenginenews.org/meng/q...
About Chronova Engineering Ltd:
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We're a small team of scientists and engineers who love making cool things! If you'd like to see what else we get up to, please subscribe to our channel and visit our other sites: linktr.ee/chronovaengineering
Credits:
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Filming: Alastair Godfrey
Editing & voiceover: Mike Godfrey - Věda a technologie
I used to do this back at tech college, along with cylindrical and flat grinding.
Loved the precision of the work
Thank you for taking the time to showcase the Quorn T&C ! It jas been on my dream project list for a few years and this is an inspiring example👍
Excellent! I was taught to sharpen drills manually, and the activities of offsetting the bit and rotating it about an imaginary conical path (i.e., how I was taught) seem similar to the way this device works. Though I say so myself, I'm pretty good at sharpening drills, but it's fair to say that while mine cut holes through metal, they can't be as accurate as machine-ground bits.
All elements in a well conceived and executed production. So well done! Thank you.
Very interesting and informative. Thank you for sharing. 👏👏👍😀
Fantastic grind! The two chips came out simultaneously. 👍👍👍
Thank you for creating this video!! Very interesting indeed. A bit fiddly in setup, but excellent results. I suppose once you get used to the setting up, it goes smoothly. Very precise results. Drills perfectly.. Rivals some very expensive drill grinding equipment.
my new favorite channel
Brilliant!
Brilliant machine. lovely grind...almost feel like I've wasted 35 years perfecting this by hand.
Yes, enjoyed the setup. Keep wondering if there is a simpler way?
Amazing, it is so hard only by hand!
You must be kidding.
Now all we need is a Quorn cutter grinder., it is a it tedious though........I think I'll stick to hand grinding drills like I've always done........I like the video, very clear instructions for anyone who also has a D bit grinder.
Amazing tool. I wish I could own one.
Looks great well built, not sure I would have the commitment and patience to build that, setting up is also rather difficult it seems.
Now I see why my manual grinding technique makes my bits feel duller. I put all my work in the tip edges and didnt think the relief would need to be cleaned up too.
Very clear tutorial for that particular machine.
I'd raise a separate issue: that drill has been accurately ground on the cutting edges but not properly sharpened.
Note the worn margin lands adjacent to the corner intersection. While this drill would perform adequately in soft steel, aluminum, or brass, production drilling in tougher or harder materials would not go too well. The worn land has in effect a forward taper that will tend to wedge against the walls.
The worn margins chafe against and work harden the hole walls resulting in heat, short tool life, poor finish, and possibly siezing.
That worn drill should have been rough ground back at least 3mm to clean undamaged margins then sharpened.
As a tool and die maker/toolroom guy I agree
I’d really love to build and own a universal tool grinder but sadly I don’t think my small Sherline lathe and mill are capable to making the parts for this, maybe one day I’ll see one on the market place and make the purchase. Absolutely fantastic content as always from this channel
You can absolutely make one with the tools you have. You're going to have to design it around your machine's capacity. Or better yet, figure out how to make small parts that combine together into the big parts needed. Or find alternative ways of making things. Or put lysergic acid diethylamide into your morning coffee and figure out how to reinvent the Universe.
When I entered machinist school in the mid 70's, one of the first things we learned was how to sharpen a drill bit. Nearly 50 yrs on, I can sharpen a drill with my eyes closed. Seriously.
Вася ты никогда не заточишь сверло так как станок!!!!!
But does the chips come out evenly on the two flutes?
And how much oversize do you usually make?
Your drill bit grind might be adequate for your use. But it might be inadequate for others. To each his own.
@@ramonching7772 You adjust the grind until the flutes are even. It also depends on the size of the drill.
Build a Quorn years ago fantastic project and machine 😊
Believe me a decent manual grinding gives very useable results.
And way quicker, just takes a bit of practice. Lifes too short for this kind of setup
Thank you for publishing this video. Will you be discussing how to calculate the axial and radial offsets for any given drill size? I've watched this beautiful video several times and I would like to try this technique on my QUORN using my version of Professor D.H. Chaddock's (designer of the original QUORN) "Setting Micrometer" to set the axial and radial offsets. My version can do axial and radial offsets up to 1" but I have no idea how to do the calculation for a specific drill size.
Thanks again.
F.C.
I think I saw that J Hugel died recently. I would have liked to witness a discussion between him and Professor Chaddock!
Thank you for making his drill-grinding process more intelligible. I note that you are using an extended mounting bar for the work-holder.
Thanks for watching and good spot. The extended bar is useful for the ER32 collet adapter due to the extra length.
Quel tornio è FOTTUTAMENTE PRE-CI-SO
What size ER collets are you using for the small drill bits?
Really nice video, thanks! I didn’t understand why the angle was moved to 25° and then back to 0°?
The first part is setting the dial to 25 degrees, then locking the dial to the drill bit and finally rotating the combined drill and dial back to zero. (You could skip this but it's easier to know you're at the right angle when the dial reads zero.) The 25-degree angle is τ in Hugel's instructions (see link in description).
@@chronovaengineering ah I see, thanks!
I once sharpened a 4mm drill bit by just eyeballing it on a bench grinder, definately not perfect but it drilled just fine.
Como calcular la distancia de compensacion lateral segun el diametro de la mecha
is the axial distance value for drill bits above 10mm the same,sir ?
Wish you could also show how centered the point is with the microscope.
I usually grinding drill bits manually by hands, its not perfect but it gets the jobs done.
But I'm not dexterous enough to grind a BallNose, I always messed up the rad...
can this machine do BallNose?
where I can purchase above type of magnifier ?
adjustable vice for tools grinder
Could this be done with a German D bit grinder?
Did you find out if this could be done?
Wonderfully clear and consistent graduations on those Quorn scales - one of the jobs I'm not looking forward to! Would appreciate any pointers...
I think you meant "perpendicular" to the axis of rotation @ 2:17 i.e. parallel to the the rotating workhead centre line. It took me a little time to understand your "parallel to the axis rotation" statement until the set square was mentioned. Sorry to be picky but maybe this comment will help others fully understand that part of the setup. I built a Quorn with extended bars and other enhancements and it took me 3 years of hobby time to complete but I wouldn't be without it now - I don't use it for drill sharpening as my hand skills in this department are quite adequate for any size of drill. If you have a drill with a chipped land then you are best to course grind the cutting edges (at 118 degree angle - equally) until the chip is no longer visible before you do the fine detailed sharpening.
Me, who has never sharpened a drill bit in my life: "hmm, yes, interesting."
⚙️👍👍👌
It's lovely that these guys refer to each other as doctors and misters ... like someone need emphasize how sophisticated the people behind these home shop projects are. Just tell Jack designed it and let the end product speak for itself.
he hand tightened his drill, . . . . .. DO NOT FOLLOW THIS ADVISE
@@kevinspacey5325or your spelling of advice.
It’s just normal language,and respectful.
@@flyerphil7708 "It’s just normal language,and respectful."
OOOH!!!!! He missed a space in there. . . .
Seriously though, you really are pathetic.
I would respectfully suggest to those people who are watching these videos, that you purchase a supply of twist drills to begin your own self help training program. The twist drills can be either no-name new drills, or used/damaged drills from an industrial salvage warehouse, or at a flea market.
I will add a point that I learned as a high-school senior in 1965. The half dozen guys that worked in a local shop, where I worked in the mornings, sharpened most of their twist drills on a 6”x48” belt sander. It sounds a bit odd, but does work very well. The surface is always flat, and grits can be changed quickly. Many of you folks already do own a 2”x72” grinder that will sharpen many of your drills.
Whether you use a grinding wheel, or a belt grinder, you then need good lighting, a can of water, and a comfortable stool of the correct height. Then you begin to practice as long as it takes. In my apprenticeship, I had the opportunity to spend three months in the tool grinding department. The first order of the day was to sharpen all of the drills that a large shop(150 men) had used the day before. This is a lot of good practice. Everything from #52 tire mold vent drills under a microscope, to 4” taper shank( Morse taper #6). The large ones were sharpened on a machine. There were usually 20-50 pieces to sharpen each day. Some of the guys would check out a drill from the crib, and come to have a “favorite” point geometry added.
Watching a knowledgeable person grind a few drills in order to get the proper hand placement, and the “swing” motion of the shank end. The worst thing that I have seen, is to watch an “expert” holding the drill cross handed. With a right hand helix twist drill, the right hand supports the point end, and provides the pivot that the drill swings about, while the left hand drives the twist drill, through that arc that provides the good cutting drill. The thing that few people explain, or even understand, is that the drill point has a steadily changing clearance angle from the dead center, which is the greatest, due to the smallest diameter, and gradually becoming lesser as you move outward to maximum diameter. The dead center is the part of the drill point that scrapes the metal, and gradually becomes more efficient as the rake increases towards the outside edge.
Once you have mastered the proper point angle, and good clearance, which allows two nearly equal chips from the flutes, your next step should be to learn to thin the web, and/or split the point to reduce that retched dead center.
You can learn to hold the drill straight up, at arms length toward a white surface to observe the equality of the point angles and lengths. The grab your trusty drill point gage to verify you judgements. Make it a challenging game, and not some tedious chore that you don’t want to do. It is a skill that will be admired by others, and can be taught to members of either sex.
So is this considered obsolete these days? I get that a drill doctor is consumer grade garbage compared to this, but I'm guessing that there is a professional equivalent to it now that doesn't require so much setup as this. Am I correct?
I love this video. Even if you lost me quickly. I love the way old machines were built before value engineering was a thing.
for drills this machine might be a bit of overkill, but it's also used to make lathe tools & sharpen milling cutters and that sort of thing where you might want much finer control over the geometry (:
@@roseroserose588 I can see that application. Thank you.
In a modern production environment, the machinist is way too expensive per hour to be sharpening drillbits in this way.
Small drills get tossed away when dull, and bigger drills are collected and sharpened once in a while.
Or when the application is less critical, they are sharpened by hand.
These machines are one of the best ways to sharpen a drill (or endmill). but are unfortunately getting obsolete in a modern production environment.
@@neruelk The Quorn T&C grinder was never intended for production use. Foe the serious hobbyist it is an excellent piece of machinery.
Interesting I suppose ------- but the Quorn Tool & Cutter Grinder is also about as rare as hens teeth.
They are indeed. The other option is to make one yourself. You can buy the castings from Hemingway Kits (UK).
It's not rare at all, you can buy them any time you wish
my drill doctor doesn’t have as many levers
Where does one acquire such a microscope?
There is no reason why a Quorn cannot be commercially manufactured instead of the D bit grinders............most of the time consuming fiddly bits could be separately made and offered for sale and the basic parts made in the home workshop......everyone wants a Quorn or so it seems.......there could be a whole mini industry just to make Quorns for the enthusiast if it was broken down to it's basic parts.
Way too complicated.
If you want drill bits that are a joy to use, this is the way though. You can CNC mill preset collet holders for various drill sizes and cutting angles, to avoid manual setup. It’s then pretty idiot-proof. I’d go as far as machining the collet tapper and threads for the nut on the jig, so that the collet just pops in and can be retained so the drill diameters don’t get mixed up. Takes an offset lathe chuck if you want to start with a reasonably small workpiece, since the collet bore is off-center.