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Axkiker
10-12-2014, 02:58 PM
So.... this winter I plan on building a drill sharpening system. Ive been wanting to do this for awhile and will finally have the time. After researching a few of the different types I seem to have narrowed the design down to 2 types. The first uses a rotational motion to sharpen the bit. Kinda like the drill dr but in a more vertical position. This type produces a convex / rounded profile on the bit. The other is one moves the bit in a linear motion like the tormek system. Anyone have any advice as to which method would be better. My initial thoughts are to build it like the tormek system. This would allow me to grind a split point multi angle bit much easier... Plus I could adapt for straight blades / end mills and such. My concern is that I just dont see many bits from the factory ground like this. This makes me wonder if there are any pros and cons between the two

Any thoughts??

Jim Hubbell
10-12-2014, 03:48 PM
I thought about it also. Decided to work on a multi facet type jig. Am to the point of testing the concept with a crude but workable unit. Will follow your thread to see what comes up.

Paul Alciatore
10-13-2014, 12:30 AM
I have to agree with Jim, a multifaceted type jig is more versatile. The split point style grind is very desirable. And there are at least a half dozen other types of tips that it can do.

oldtiffie
10-13-2014, 03:48 AM
Good worthy ideas but why not practice and become proficient in free/off-hand drill grinding. It might take a while and needs relatively frequent practice to keep your skill-set up to date.

Its a very satisfying feeling when you get it right.

Same applies to free/off-hand grinding of HSS tools for lathes and fly-cutters etc.

I was taught to "hand" grind" tools as an Apprentice - 60 years ago - and I still use it as my default/"go-to" method even though I have adequate tools to do it on my pretty good range of specialist grinders.

J Tiers
10-13-2014, 08:45 AM
A reasonable-looking design was written up in the magazine that just happens to sponsor this site. Last year maybe. recently in any case.

A 4 facet sharpener with point splitting.

Bound to work a hundred times better than the stupid Drill Doctor that wears out after a few drills

Rosco-P
10-13-2014, 08:55 AM
One consideration would be the range of bits you're going to sharpen. Cloning a darex would work for most bits up to 1/2" I'd rather have a Stirling type drill grinder for anything bigger.

Axkiker
10-13-2014, 09:35 AM
A reasonable-looking design was written up in the magazine that just happens to sponsor this site. Last year maybe. recently in any case.

A 4 facet sharpener with point splitting.

Bound to work a hundred times better than the stupid Drill Doctor that wears out after a few drills

Do you know if its possible to get back issues ?

Thanks

Axkiker
10-13-2014, 09:37 AM
Good worthy ideas but why not practice and become proficient in free/off-hand drill grinding. It might take a while and needs relatively frequent practice to keep your skill-set up to date.

Its a very satisfying feeling when you get it right.

Same applies to free/off-hand grinding of HSS tools for lathes and fly-cutters etc.

I was taught to "hand" grind" tools as an Apprentice - 60 years ago - and I still use it as my default/"go-to" method even though I have adequate tools to do it on my pretty good range of specialist grinders.

Well, I do agree that having the ability to hand sharpen a bit is a skill any wannabe machinist like myself needs to have. Its my opinion though that no one no matter how good they are or how much they practice can sharpen as well as a machine designed for the task.

Plus it gives me something to build lol

George Bulliss
10-13-2014, 09:41 AM
Do you know if its possible to get back issues ?

Thanks

I believe the article J Tiers is referring to is "A Four-Facet Drill Sharpener" by John Moran. It ran in The Home Shop Machinist issues Jan/Feb 2012 and Mar/April 2012. Back issues are available by calling 800-447-7367.

DR
10-13-2014, 10:22 AM
I pre-grind badly dulled bits by hand grinding, then finish off with a precision, dedicated drill grinder. The reason is I don't want to waste the expensive CBN wheels roughing down a bit.

Learning the geometry of a correctly sharpened bit is worth doing. Trying to accurately sharpen bits by hand to drill as on size as possible seems to me to be wasted effort. If anyone claims to be able to hand grind to the accuracy of a good factory grind then I suggest they probably don't need measuring tools to machine to .001" accuracy either.

GadgetBuilder
10-13-2014, 10:28 AM
Multi-facet grinds require multiple passes, one for each facet, so sharpening takes longer and drives the price up - that is likely why they're not common commercially. Split point drills are usually more expensive than conical points for this reason.

Overview info on the 4 facet sharpener presented in HSM is here:
http://www.gadgetbuilder.com/DrillSharp.html#Facet4

Cost to build is about $130 assuming you use the small Harbor Freight grinder, a modest cost CBN or diamond wheel and ER collets from CTC. And assuming a modest supply of scrap.

John

Old Hat
10-13-2014, 10:42 AM
In many twist drills anymore, the two gullets will be found to have either
two different forms, and/or two different depths. Lax quallity controll in all but
the highest end manufacturers.

May as well get good at free-handing. Because with drillls like this a "perfect grind"
isn't going to do it. You'll test your grind, and drill as much as 3 times oversise
what would have once been considered an acceptable result.

To salvage the bit you'll have to grind a compensation.
Any douts on this, section the gullet on a suspect drill on a comparator.
index 180 and get out the vomit bag.

sarge41
10-13-2014, 12:56 PM
Learning to hand-grind drills is indeed an excellent skill. When grinding a drill, I was taught (in the apprenticeship by the old journeymen) not to "roll" the drill . Always "drop the taper end". Try two drills, one each way, and then compare them to a brand new drill. No contest. Good luck.

Sarge

justanengineer
10-13-2014, 02:44 PM
JMHO, but I'd suggest just buying a good used Darex M3-5 and building your own accessories as desired. $2-300 for them is pretty common once you get past the insane craigslist and ebay $500+ price tags. My current one was $250 in literally "only used a couple times" in a home/hobby "sharpening" shop and included the BNIB accessories for oversize drills, spade drills, and quite a few other things that I have to attempt still.

Admittedly, Ive thought about building my own cnc drill sharpener to speed up the process with some sort of automatic loading/unloading, but that was after staring too long at the cnc sharpening centers at work and dreaming of owning a similar business. Reality I believe today tho is that drills are considered expendable by too many to be worth it.

Rosco-P
10-13-2014, 03:12 PM
+1 to what sarge41 said, hand sharpening is a skill worth leaning.
+1 to justanengineer. Buy a good drill grinder and be done with it. It may not do 4 facet grinds, but are you running production? Can you live without it?
IMHO, small drills can be cheap enough to toss when dull, just picked up some less than full packs of new National, Barnes, Illinois, PTD, etc. , over 100 pieces, wire size drills, #40 through #60, at a tag sale, $20. I can't be bothered squinting through a loupe to align a drill in a jig for less than 20 cents. Drills 0.125 and bigger, that's different all together.

oldtiffie
10-14-2014, 03:53 AM
If nothing else, trying to make sense of and/or us a number of "drill grinders" will or may drive you to hand-grinding - same applies to lathe tools. The set-up and ter-down timeas and set-ups can be - to put it mildly - time-consuming and a PITA.

My common pedestal grinder and belt sander combo work very well.

alanganes
10-14-2014, 06:49 AM
While I have been able to get an acceptable grind by hand, I do find that I just don't do it often enough to stay good at it. I finally came across an old M5 Darex, and find it pretty easy and quick to set up and use. Even with the marginal grinder (vibration is a bit excessive, need to revisit that) that I am using it with, I get sharp bits in no time.

I have a decently well tooled up T&C grinder, so a four facet jig was always in the back of my mind. May still do that at some point for the larger bits that don't fit the Darex as I am missing the larger chuck, but it seems to have slid down the list some.

J Tiers
10-14-2014, 08:22 AM
You can get close with hand grinding. I do it routinely , even for smaller drills, if the alternative is not having a drill. I ALWAYS hand grind big drills, because none of the grinders I have can hold a 1" drill.

That said, if you can freehand grind a close to perfect 4 facet split point, you are darn good. Even on a large drill.

My suggestion is that if you find setup a pain, try just not drilling the hole.... That is probably even more of a pain, since you have to stop what you are doing, until or unless you can get a suitable drill that is sharp enough to function.

When possible, grind several similar sizes, so that you get some efficiency.

oldtiffie
10-15-2014, 07:16 AM
There may be an underlying assumption here that if the drill is ground perfectly and that all will be OK.

Perhaps not.

If the assumption above is correct the drill end and tip will be spinning perfectly centred on the mill or drill quill centre and that left to its own devices the drill will not "wander off".

Perhaps it will - but perhaps not too.

J Tiers
10-15-2014, 08:29 AM
Yah Tiffie... you do have to use it right....

But a properly ground split 4 facet drill is a joy to use. It does not wander much if at all with NO mark, stays in a punch mark well, and drills freely in any decent material. For resistant materials, it might not be the best grind, but that's no reason to dismiss it. I suggest that your worries and concerns are perhaps exaggerated.

oldtiffie
10-16-2014, 09:02 AM
I don't recall my "worries" being "perhaps exaggerated" as I don't have any such "worries" hence it follows that I can't (and don't) worry about those concerns that I don't have.

Black Forest
10-16-2014, 10:06 AM
A few years ago I built a drill sharpener. I bought the drill holder from Kaindl. If I remember correctly it cost me right around 200 Euros. That included the prism, tower to hold the prism and the diamond wheel dresser. I bought a small compound/cross slide for a very small lathe off of Ebay. 90 Euros I think. A 70 Euro Quantum bench grinder.

The compound/cross slide has handles that move the compound in X and Y directions. Each direction has two stops that can be set to limit the in and out travel. This makes it quite easy to get each lip ground the same.

This drill grinder allows me to do any type of grind I want on a drill including Forstner bits, step drills, carbide concrete drills, four facet grinds and split points. And it doesn't take long at all to do a drill.
http://i853.photobucket.com/albums/ab91/burnandreturn/drillsharpener.jpg (http://s853.photobucket.com/user/burnandreturn/media/drillsharpener.jpg.html)

Axkiker
10-16-2014, 02:53 PM
A few years ago I built a drill sharpener. I bought the drill holder from Kaindl. If I remember correctly it cost me right around 200 Euros. That included the prism, tower to hold the prism and the diamond wheel dresser. I bought a small compound/cross slide for a very small lathe off of Ebay. 90 Euros I think. A 70 Euro Quantum bench grinder.

The compound/cross slide has handles that move the compound in X and Y directions. Each direction has two stops that can be set to limit the in and out travel. This makes it quite easy to get each lip ground the same.

This drill grinder allows me to do any type of grind I want on a drill including Forstner bits, step drills, carbide concrete drills, four facet grinds and split points. And it doesn't take long at all to do a drill.
http://i853.photobucket.com/albums/ab91/burnandreturn/drillsharpener.jpg (http://s853.photobucket.com/user/burnandreturn/media/drillsharpener.jpg.html)

Yup that is exactly what I had in mind. I ran across a cross slide at the flea market last week. I thought about buying it for this purpose and didnt. Im now kicking myself.

Black Forest
10-16-2014, 03:05 PM
Im not kicking myself.

Why not?

Axkiker
10-16-2014, 03:39 PM
Im not kicking myself.

Why not?

Sorry.. keyslip.... should have read NOW kicking myself.

Black Forest
10-16-2014, 04:07 PM
Tomorrow I will try to make a video of how easy it is to sharpen a drill and split the point.

Axkiker
10-16-2014, 04:18 PM
Tomorrow I will try to make a video of how easy it is to sharpen a drill and split the point.

That would be awesome... I would love to see it

Black Forest
10-17-2014, 01:16 PM
Here is a short video of the different components of the drill sharpener I put together. On the commercial unit built by Kaindl the BSG 20 it uses knobs to move the drill holder in and out to the grinding wheel and across the wheel. I use a compound and cross slide I bought on Ebay that is for a very small lathe. It uses levers not handwheels to move the axis. It has stops to limit the travel in both directions. This is better because when I grind one side and set the stop when I come back in after flipping the prism I can only go so far in as the stop. No having to look closely and watch any markings. I should have set the camera up and video me doing a drill as I would if I wasn't filming and trying to show the different steps. I would say it takes a little over a minute to do one drill including splitting the point.
http://youtu.be/btfWkmgVyts

Axkiker
10-18-2014, 12:17 AM
Here is a short video of the different components of the drill sharpener I put together. On the commercial unit built by Kaindl the BSG 20 it uses knobs to move the drill holder in and out to the grinding wheel and across the wheel. I use a compound and cross slide I bought on Ebay that is for a very small lathe. It uses levers not handwheels to move the axis. It has stops to limit the travel in both directions. This is better because when I grind one side and set the stop when I come back in after flipping the prism I can only go so far in as the stop. No having to look closely and watch any markings. I should have set the camera up and video me doing a drill as I would if I wasn't filming and trying to show the different steps. I would say it takes a little over a minute to do one drill including splitting the point.
http://youtu.be/btfWkmgVyts

Thank you for the video!!!

Im a little more confused now. When I first saw your pics I thought you were going to grind it much differently. I thought the bit would move side to side instead of the rolling action you provided by hand.

That leads me to the question of ... "is there a benefit to either style".

Regardless thats a great rig you have built. Do you know what the cross slide that came off of. Its seems ideal for multiple projects I have in my head.

J Tiers
10-18-2014, 12:19 AM
Nice. Not clear to me how the splitting is done, but evidently does a good job.

I think I would have a guard on that wheel though... I have seen a wheel come apart (a small one), and did not much like it.....

sawlog
10-18-2014, 07:51 AM
Great tool. I use the SRD style drill grinder, picked it up on e-bay for cheap,but had to order the drill holder from SRD. The drill chuck is similar to yours except it doesn't have pin mounts.

Black Forest
10-18-2014, 10:55 AM
I made a short video to show how the drill gets the point split.
http://youtu.be/vg3zIL5zX5k

J Tiers
10-18-2014, 11:12 AM
OK, that makes sense. Nice device.

I see that the holder seems to be a replacement part for the drill grinding machines such as BSG 20/2. I didn't see it listed by itself

http://kaindl.de/en/bsg-20-435.html

Black Forest
10-18-2014, 11:26 AM
OK, that makes sense. Nice device.

I see that the holder seems to be a replacement part for the drill grinding machines such as BSG 20/2. I didn't see it listed by itself

http://kaindl.de/en/bsg-20-435.html

I called the Kaindl headquarters and bought all I needed without any fuss. I am sure they would rather you purchase a whole machine than just the prism. I did tell the man on the phone why I wanted the prism and he said no problem.

Axkiker
10-18-2014, 10:50 PM
Sorry for my ignorance but would the way you grind a drill be called a 4 facet grind ???

I was kinda basing my possible build on the Tormek machines http://www.youtube.com/watch?v=KqcMTxrIoPY

It appears they put a finish edge on the bit almost like a knife has a primary and secondary edge. Does splitting the point as you did create that same 4 facet grind?

Also, as you see in the tormek video they tend to move side to side... Any pros or cons to this.

Regardless you have built a great machine!!! Im just trying to sort out how I want to build mine. Do you know what the cross slide you are using came off of. I would possible like to use a similar one on my future build.

Thanks

Black Forest
10-19-2014, 06:23 AM
No, that is just a plain ol grind with the point split. Look at the first video again. Watch how I swivel the prism holding the drill up and down. That puts a rounded end on the drill. The amount of relief behind the cutting edge is controlled by how much you turn the bit in the prism before tightening it up. There are two lines in the end of the prism and the cutting lip gets aligned to these lines. A little twist more or less puts more or less relief.

If the drill is fed across the face of the grinding wheel that would work for four facet but not for the normal rounded end.

I have no idea what lathe brand the compound/cross slide was built to go on.

garyhlucas
10-20-2014, 10:07 PM
I have been following this thread because i could use a sharpener. I stopped at a scrapyard/used machinery place this morning. Came home with a Black Diamond drill sharpener in very nice shape with all the collets from 1/16" to 3/4". The point splitter casting is broken but I can repair it or get a new one easily. Nice machine, two diamond dressers built in, one for the side, one for the rim. Runs smooth as silk. The best part, $395! It's been a really good machinery month.

Axkiker
11-24-2014, 03:01 PM
So im back to planning this project out. I plan to build this sorta similar to the " Four-Facet Drill Sharpener" by John Moran

I like the way he designed the drill holder to be moved side to side which allows the 4 facet grind. What im contemplating is what would be the best method to alow that side to side motion. I am not particually fond of the way he built his "slide" mechonisim . I would like this to eventually be a multi-purpose tool grinder so im looking for more accuracy.

Any suggestions. Whatever I use I would like for a slotted table to be mounted. This would allow me to mount the 3 axis grinding fixture I have or whatever I may build in the future. My first thoughts were to use linear slides. This would be a pretty easy way to mount the table and from my understanding they are very accurate. The only drawback I can think of is how to solidly lock the table down.

Another idea would be to just grab some stock and machine a sorta crosslide. Having gibs would allow me to solidly lock down the table but would be considerable harder to build.

Any ideas

Axkiker
11-26-2014, 10:02 AM
Anything???? Anyone have any experience building with linear slides ? Ive never worked with them so im not really sure of pros / cons