Drill bit sharpener

[pontiac428]

What I don't like is being treated like a moron after hundreds and hundreds of attempts with varying degrees of success and being told I'm doing it wrong while following the directions.

I'm following directions with the new machine and getting reasonably good results without clocking issues.

I'm not treating you like a moron. You, like many others, obviously see a unit like the Drill Doctor or Vevor as a "black box".

In science, computing, and engineering, a black box is a system which can be viewed in terms of its inputs and outputs (or transfer characteristics), without any knowledge of its internal workings. Its implementation is "opaque" (black). The term can be used to refer to many inner workings, such as those of a transistor, an engine, an algorithm, the human brain, or an institution or government.

To analyse an open system with a typical "black box approach", only the behavior of the stimulus/response will be accounted for, to infer the (unknown) box. The usual representation of this black box system is a data flow diagram centered in the box.

The opposite of a black box is a system where the inner components or logic are available for inspection, which is most commonly referred to as a white box (sometimes also known as a "clear box" or a "glass box").

Part of the reason it is a black box is that you can't see inside. You stick a bit in here, turn and rock there, and out it comes. You have no way to troubleshoot an unexpected result. You followed the instruction, but didn't know enough about what is happening inside the black box to affect change. This is the main complaint about drill doctors in my opinion. It takes some sort of second sight to know that if you grind off the tip of a drill, you need to re-index the helix to get the right grind. I don't know how to teach second sight, but it's an important part of the process for working outside the box.

 

[Batmanacw]

I'm not treating you like a moron. You, like many others, obviously see a unit like the Drill Doctor or Vevor as a "black box".



Part of the reason it is a black box is that you can't see inside. You stick a bit in here, turn and rock there, and out it comes. You have no way to troubleshoot an unexpected result. You followed the instruction, but didn't know enough about what is happening inside the black box to affect change. This is the main complaint about drill doctors in my opinion. It takes some sort of second sight to know that if you grind off the tip of a drill, you need to re-index the helix to get the right grind. I don't know how to teach second sight, but it's an important part of the process for working outside the box.

Again, YOU treat me like a moron. I tried clocking every which way. I fought with that piece of crap for months. I tried backing it up a bit from the stop while clocking different ways. I clocked different amounts. I spent real time trying to make that garbage work. I did not see it as a black box of unknown fuction.

I am not some idiot unintelligent rube. You insult without any comprehension of who i am or what I've done in my life. I'm just hobby machinist, right?

 

[tq60]

We have 2 DD, oe bought new, the second at estate sale.

They do work as advertised, BUT they are good for ONE helix angle as the guide system is some distance from the tip.

It is not very aggressive, so if more than just a touch-up, you need to spend some time reseting the drill.

We pick up the bag or box of bits at estate sales as we find them, does okay to touch up.

The last sale we got maybe 140 packs of sealed bags of bits for maybe 45 bucks, lifetime supply...

Would love to get a "real" machine, but we are just too cheap.

Drill Doctor is darex product if I recall correctly.

As Eastwood states, one must know their limitations....

Sent from my SM-G781V using Tapatalk

 

[sdelivery]

Since I am a service man and go into many shops I see drill doctors everywhere.
I have used them on and off for years. I always sharpened by hand but as age is affecting my eye sight I started doing anything under a .250 on a drill doctor.
First the wheels are easily ruined.
The units are capable of creating a nice grind but that's with fiddling.
It seems to me like no two drill doctors are the same, what works for me on one might not work on the next.
I am thinking poor build quality.
I have looked into buying one on several occasions and can't justify the price.
Sorry might seem weird but I don't see quality/price ratio but I was taught to hand sharpen on a grinding wheels 40 years ago and with some of the drill doctors I give up and go back to the grinding wheel.
I think this explains why Bob and Tom get great results and Joe and Frank don't.

 

[Batmanacw]

Since I am a service man and go into many shops I see drill doctors everywhere.
I have used them on and off for years. I always sharpened by hand but as age is affecting my eye sight I started doing anything under a .250 on a drill doctor.
First the wheels are easily ruined.
The units are capable of creating a nice grind but that's with fiddling.
It seems to me like no two drill doctors are the same, what works for me on one might not work on the next.
I am thinking poor build quality.
I have looked into buying one on several occasions and can't justify the price.
Sorry might seem weird but I don't see quality/price ratio but I was taught to hand sharpen on a grinding wheels 40 years ago and with some of the drill doctors I give up and go back to the grinding wheel.
I think this explains why Bob and Tom get great results and Joe and Frank don't.

That very well could be the issue. Maybe some of them aren't garbage but my example was. It's not gone. My buddy hates it too. It's on a dusty shelf in his shop.

 

[MrCrankyface]

Granted I've only tried one drill doctor, a fairly new 750x with the larger chuck(up to 19mm), but considering how varying peoples experience are, I suspect the machines have varying quality from the factory.
Look around and you see people both hate and praise them.

First few grinds I did weren't great, took me maybe an hour of use to understand the machine(by trial&error, the manual is nearly useless, incorrect and doesn't explain enough, especially how chisel angle and reliefs are affected).
After that run-in period I can relatively quickly sharpen anything from 3mm to 19mm drills to good as new, sometimes better.
On a couple of the larger and cheaper drills I had, cutting pressure decreased significantly and the finished holes were closer to nominal after a resharpen.
What worked for me was to always pinch the webbing in the "endstop" and then rotate the chuck left/right depending on how the grind is.

Both helix angle and how the point has been ground will affect how the chuck "zeros" the drill bit so some gut feeling is required here.
I've mostly sharpened at 135* since that's recommended for harder materials, with regular helix angles this has usually required rotating the chuck 2 steps clockwise but other helix angles and/or if the drill tip has been split and the back of the flutes has been ground down during that process.

I agree that it's a very "plastic-y" tool but it seems to be enough to do it's job as a hobbyist/small business.
Been using it for maybe 10 hours by now, everything from refinishing tips to completely changing the tip angle and fixing broken tips/flutes.
Obvious issues are:
-Zeroing the drillbit in the chuck is fiddly and unintuitive. Often requires experience to know which setting gives you the right angles.
-Grinding process is very sensitive to how you're holding/rotating the chuck in the indexer-thing due to things flexing if you're not careful(if you want the best finish that is)
-Really requires a connected vacuum to not have grinding dust everywhere
-Larger operations takes some time, to be expected from such a small machine, it's not magic.

IMHO it feels overpriced for the quality/feel but considering that the next step up is something like the Vevor which is >2x the price, maybe it isn't overpriced. In relatively terms it's a cheap tool/machine and should be treated as such, with a delicate touch and caution.

I wish I had something like the Vevor unit, which is obviously both of better quality and more capable, but price point and budget matters more than feel in this case and every drill I've sharpened after I understood the "issues" have come out as perfect as I've ever been able to make them.

As for the starting questions rather than this rant about Vevor/DD..
118* will have an easier time starting centered, usually giving a "better" hole in that sense. Being more centered it won't act like a tiny flycutter and make an oversized hole.
135* will be tougher(more material supporting the cutting edge) but due to being "blunt" have more of a tendency to wander without a correct spotting drill to help out. Splitting the tip will help somewhat by reducing the chisel area that's forced to 'push' material rather than cut.

 

[Batmanacw]

Granted I've only tried one drill doctor, a fairly new 750x with the larger chuck(up to 19mm), but considering how varying peoples experience are, I suspect the machines have varying quality from the factory.
Look around and you see people both hate and praise them.

First few grinds I did weren't great, took me maybe an hour of use to understand the machine(by trial&error, the manual is nearly useless, incorrect and doesn't explain enough, especially how chisel angle and reliefs are affected).
After that run-in period I can relatively quickly sharpen anything from 3mm to 19mm drills to good as new, sometimes better.
On a couple of the larger and cheaper drills I had, cutting pressure decreased significantly and the finished holes were closer to nominal after a resharpen.
What worked for me was to always pinch the webbing in the "endstop" and then rotate the chuck left/right depending on how the grind is.

Both helix angle and how the point has been ground will affect how the chuck "zeros" the drill bit so some gut feeling is required here.
I've mostly sharpened at 135* since that's recommended for harder materials, with regular helix angles this has usually required rotating the chuck 2 steps clockwise but other helix angles and/or if the drill tip has been split and the back of the flutes has been ground down during that process.

I agree that it's a very "plastic-y" tool but it seems to be enough to do it's job as a hobbyist/small business.
Been using it for maybe 10 hours by now, everything from refinishing tips to completely changing the tip angle and fixing broken tips/flutes.
Obvious issues are:
-Zeroing the drillbit in the chuck is fiddly and unintuitive. Often requires experience to know which setting gives you the right angles.
-Grinding process is very sensitive to how you're holding/rotating the chuck in the indexer-thing due to things flexing if you're not careful(if you want the best finish that is)
-Really requires a connected vacuum to not have grinding dust everywhere
-Larger operations takes some time, to be expected from such a small machine, it's not magic.

IMHO it feels overpriced for the quality/feel but considering that the next step up is something like the Vevor which is >2x the price, maybe it isn't overpriced. In relatively terms it's a cheap tool/machine and should be treated as such, with a delicate touch and caution.

I wish I had something like the Vevor unit, which is obviously both of better quality and more capable, but price point and budget matters more than feel in this case and every drill I've sharpened after I understood the "issues" have come out as perfect as I've ever been able to make them.

As for the starting questions rather than this rant about Vevor/DD..
118* will have an easier time starting centered, usually giving a "better" hole in that sense. Being more centered it won't act like a tiny flycutter and make an oversized hole.
135* will be tougher(more material supporting the cutting edge) but due to being "blunt" have more of a tendency to wander without a correct spotting drill to help out. Splitting the tip will help somewhat by reducing the chisel area that's forced to 'push' material rather than cut.

My drill doctor did up to 3/4". It was one of the early versions with the squared blue body.

 

[Batmanacw]

I spent a few hours working through each setting and went to each extreme to feel out how they effect the split point. While I haven't gotten to a perfectly clean split I have gotten a very decent serviceable 135⁰ split point.

I tested the last 3 bits on rusty steel and they cut beautifully with zero damage to the tip or outer edges. The clearance behind the cutting edge is not aggressive but it is sufficient for a quick clean cut. With moderate feed the holes are extremely clean and nicely round.



It would have been nice to have this from the factory but it takes some work.

Aliexpress has the spare wheels for $45 plus tax and shipping. $60 shipped.

I'm much more pleased with it now than I was when I bought it.

 

[woodchucker]

I hate hand sharpening drill bits.....I can do it, but I'm ocd. It's gotta be perfect. It ends up taking forever.

So I bought this.

MRCM Drill bit Sharpener for High-Speed Steel, Masonry, Carbide, Cobalt, & TiN-Coated Drill Bits,with Adjustable Angles from 90° to 135°,Sharpens 3mm-20mm Drill Bits… (MR-20G)

So far 118⁰ bits are stupid easy. The base angles on 135⁰ are stupid easy.

Right now I have it set to properly split the point but I'm still working on duplicating the factory relief angle behind the cutting edge. My clearance isn't as pronounced as the factory grind but I'll get it figured out.

I've done several 135⁰ split points that cut beautifully but they look odd. Lol!

It is satisfying to watch the chips evenly curl off both edges as it cuts in steel. The machine definitely leaves a decent finish. It cuts true. So far I'm pretty excited. I drilled a bunch of holes with drill bits as I sharpened them and they cut true and broke through without damage.

I don't have any good pictures yet.



I would love to hear opinions on 118⁰ vs 135⁰ split point for the machine shop. I've mostly just duplicated what is already on the drill. The 135⁰ split point seems to have the advantage for starting without walking but it seems like 118⁰ cut truer to size and leaves a rounder hole.

Nycnc did a whole episode on the disappointment of 135 for true size and roundness. He did a bunch of testing and determined that 118 cuts a truer hole.

 

[Batmanacw]

Nycnc did a whole episode on the disappointment of 135 for true size and roundness. He did a bunch of testing and determined that 118 cuts a truer hole.

I agree. I think 118⁰ do drill a better hole. Often the 135⁰ is good enough and doesn't walk as much for punching a quick hole.

The 135⁰ this machine grinds is pretty stout. With moderate feed the finished hole looks ground. I should have taken pictures.