# Building a better mousetrap: Drill bit sharpening jig



## strantor (Jan 11, 2019)

I'm needing a way to sharpen twist drills (lots of them) quickly and consistently. I won't be doing the work myself; I have an unskilled helper doing the chore. I've tried to teach him how to do it by hand but I suck at it myself so I can't hold it against him, but his results are less than stellar. I've looked into purchasing a jig/machine but there seems to be only two kinds: 1. Cheap crap that doesn't work, and 2. Really expensive production-oriented fixtures that have more axes than a CNC robot and more adjustments than two lathes together. They also mostly use a collet system so I would need a drawer of doodads, one for each size of bit I would conceivably want to sharpen. I don't like my options. I want something of acceptable quality (or at least acceptable results) and simple enough that a Liberal Arts major can use it. Necessity is the mother of hairbrained ideas and ultimate folly. Here's what I'm thinking...

(By the way, I'm posting this for peer review. Any and all criticism is welcome. Shoot holes in it, don't hold back. I can't find examples of anything close to what I'm about to describe so that means it's either a horrible idea or revolutionary. Most likely horrible. But at the same time, the pictures are just conceptual; only enough detail convey the point. the end result wouldn't look anything like this.)

I drew inspiration for this from knife sharpening jigs such as this:







The stone is held at the end of a long rod which pivots about (and slides through) a fulcrum of adjustable height. The long distance between the knife's edge and the fulcrum point allows the setting of precise angles with relatively crude hardware.

My jig is the same concept but in reverse. The "stone" (grinding belt) is held stationary and "knife" (drill bit) is mounted on a mobile rod. The slot plates are interchangeable and with the plates shown, should produce general purpose 118deg 4-facet bits.




The image above depicts the jig fitted with a 1/2" 4-facet drill bit, grinding the relief edge.
The image below depicts the jig fitted with the same bit, but grinding the cutting edge.




Below is a top-down view from above the grinding belt. The drill bit is held in a cordless drill chuck which is mounted on the end of the paddle pole.
The belt is mounted to the plate behind, at an angle of 118 deg. This angle is adjustable. The belt assembly is mounted to its backing plate with linear slides, so it can be moved side-to-side for even belt wear.




The sequence of operations would be as follows:
[with belt off]
1. Loosen the locking collar and place paddle pole into slot plates A and B (cutting edge grinding position)
2. Insert bit to be sharpened in paddle pole chuck, with cutting edge 90deg to belt.
3. Slide paddle pole forward until bit touches grinding belt, slide locking collar forward until it touches slot plate A.
4. Back locking collar off [some small distance*] from slot plate A and tighten.
* this small distance sets the amount of material to be removed. it will depend on the size of the drill and condition. If only a touch-up resharpening is desired, then maybe use a few thousandths of shim stock to set the depth.
5. Back paddle pole away from belt, energize belt.
6. Slide paddle pole gently in towards belt, and continue to apply gentle pressure until locking ring bottoms out against slot plate A and the belt stops cutting.
7. withdraw paddle pole away from belt, carefully remove paddle pole from slots, and without adjusting the chuck or locking ring, flip it over and put it back in the slots.
8. Feed paddle pole forward, gently grind 2nd cutting edge until locking ring bottoms out and belt stops cutting.
9. Withdraw from cut, remove paddle pole, place in slot plates A and C (Relief grinding position). loosen locking collar.
10. Paying close attention to cutting edge thickness, feed paddle pole into grinding belt until desired cutting edge thickness is achieved.
11. Set locking collar up against Slot plate A and tighten.
12. withdraw paddle pole away from belt, carefully remove paddle pole from slots, and without adjusting the chuck or locking ring, flip it over and put it back in the relief grinding slots.
13. Feed paddle pole forward, gently grind 2nd relief edge until locking ring bottoms out and belt stops cutting.


So, by utilizing the locking collar to feed forward to precisely the same distance on both sides, this should ensure precisely the same length of cutting edge on both sides, if my logic is correct. A perfectly symmetrical grind at precise angles. And with taking most of the "art" out of the task, maybe it now makes sense to sharpen smaller drills rather than replace.

The slot plates B and C are drawn appropriately for a 1/2" drill bit, but would be made to extend in both directions (up & down) with multiple stops within the slots, to achieve a variety of cutting edge & relief angles for different sized bits (and those stops could be marked in drill bit sizes for simplicity, ex: "use this position for 5/32 & 4mm bits")

Ok, take your shots. Why won't this work?


----------



## T Bredehoft (Jan 11, 2019)

Maybe I missed it, but what provision is there for keeping the  cutting edges the same length?


----------



## Bob Korves (Jan 11, 2019)

I think you are over thinking this, but of course, that is what we do as Hobby Machinists, and are proud of it!

Get yourself a sharpening jig and a bench grinder, and learn how to use it.  This type:


They are quite inexpensive new, and can often be found dirt cheap, lightly used by people who did not read the instructions and think beyond them.

Has been sold by many companies under different brand names, and it works just fine after you understand how it works, including beyond the dumbed down instructions that come with it.  You seem to understand the concept, and have skills good enough to post a very nice graphic post of what you have in mind.  The jig above will do what you want, with a whole lot less investment in time and effort.  It is designed to do what you are trying to do in your post, and it gives nice results -- if you are smarter than it is...  It also has adjustments for several drill point angles.

I have ground several hundred drills in this type of jig before buying a Drill Doctor, which also works very well after you understand how it works and how to get there.  They all turn out fine once you understand the setups and adjustments and know what you are looking for with various drilling operations.

Edit:  By the way, the setup in the photo above is wrong, WAY too much overhang of the drill beyond the end of the holder...


----------



## Liljoebrshooter (Jan 11, 2019)

Why not try a drill doctor? I don't have one but have heard they work pretty good.


----------



## Latinrascalrg1 (Jan 11, 2019)

My first thoughts on your design were as follows.....Why does it need to be so big, are you sharpening Industrial Giant sized drill bits?
By trying to simplify it in the manner you have outlined with the plates and multiple positions, I think you will end up with an over complicated settup (at least not something a Lib Arts major wont have trouble with, lol).

Wouldnt a few "protractors" somehow attached to a few adjustable "Joints/Knuckles/shaft assemblies" be much more effective without the need to take up half of your floor space?

Edit: lol i started typing when there where no replies and by the time i finished i I was beat to the punch....I really Suck at typing, lol


----------



## strantor (Jan 11, 2019)

T Bredehoft said:


> Maybe I missed it, but what provision is there for keeping the  cutting edges the same length?


When you feed in on the first side until the locking collar bottoms out, and then you flip it over and again feed it in until the locking collar bottoms out, that's where you get your symmetrical grinds. In (my) theory, anyway.


----------



## strantor (Jan 11, 2019)

Liljoebrshooter said:


> Why not try a drill doctor? I don't have one but have heard they work pretty good.





Bob Korves said:


> I think you are over thinking this, but of course, that is what we do as Hobby Machinists, and are proud of it!
> 
> Get yourself a sharpening jig and a bench grinder, and learn how to use it.  This type:
> View attachment 284552
> ...



I've spent an appreciable amount of time reading & watching reviews for Drill Doctor and the inexpensive sharpening jigs. I have no doubt that I could make them work with enough practice and figuring out the finer points of how they work. But I don't intend to do any of this myself. I've already wasted enough time teaching myself (with marginal success), and then my apprentice (unsuccessfully), how drill bits work, the geometry behind them, and how they should be sharpened. This is 50% personal and 50% business (I own a small business and it isn't a machine shop but we do use drills) so I can't treat it the same way I treat my pet projects. It has to make sense money-wise. I want something I can hand off to someone else, who doesn't have the same technical background as I do, and have it "just work" (idiot proof). If I can't have that, then I need to just move on. Maybe send the bits off for sharpening. Or forget about them, hang on to them for the next 35 years until I retire.

I don't even intend to build this jig myself. If I can believe in it enough to go forward, I'll model some patterns and have my apprentice cut out his own sharpening jig and assemble it, probably out of plywood.



Bob Korves said:


> Edit:  By the way, the setup in the photo above is wrong, WAY too much overhang of the drill beyond the end of the holder...



Point taken. I'll address that before I make anything. Maybe put a V-plate up by the belt as the final resting surface for the end of the bit.


----------



## strantor (Jan 11, 2019)

Latinrascalrg1 said:


> My first thoughts on your design were as follows.....Why does it need to be so big, are you sharpening Industrial Giant sized drill bits?
> By trying to simplify it in the manner you have outlined with the plates and multiple positions, I think you will end up with an over complicated settup (at least not something a Lib Arts major wont have trouble with, lol).
> 
> Wouldnt a few "protractors" somehow attached to a few adjustable "Joints/Knuckles/shaft assemblies" be much more effective without the need to take up half of your floor space?
> ...



It doesn't _*need*_ to be big, it's just that... ok, so the angle of the drill, the angle of the sanding belt, and their relation to the floor form a triangle. The more distance there is between the 3 points of the triangle, the more accurate the angle can be, utilizing crude materials and construction methods. Also, it minimizes error in setup and use. This is probably going to be made out of plywood and built by my apprentice. I can't justify spending any time on the clock machining parts for it. No machining, quick & dirty. That's why it's big. If it works as I hope, and I find there to be any market for it than anyone would be interested in purchasing something along these lines, I could make machined versions much smaller.


----------



## Bob Korves (Jan 11, 2019)

strantor said:


> Point taken. I'll address that before I make anything. Maybe put a V-plate up by the belt as the final resting surface for the end of the bit.


On that 'specific' drill grinding jig, the overhang should be about half the drill diameter beyond the "tooth" that engages the flute of the drill, for a 'standard' 118 degree drill, so the drill has the correct clock orientation to the grinding wheel for making a proper grind.  However, different point angles, different twist rates of the drill, and what the drill is intended to be used for, all come into play and require changed settings for best results.


----------



## Bob Korves (Jan 11, 2019)

There are at least dozens, if not hundreds of differently designed drill jigs available on the new and used market, from under $5 to thousands of dollars.  They all work if used properly, some better and more quickly and easier than others.  Drills are used in many industries and in many home shops, so there is a huge market, but it is already pretty saturated with products that do the job if the operator does his job correctly.  Drills can also be ground to a proper point without any jig at all, just eyes, brain, tool rest, and bench grinder.  It is done all the time, some far better than others.  I grind all my drills 3/4" and above by hands and eyes to a good result, checking them with a drill gauge.  Drill bit grinding tooling has been studied, better mouse trapped and improved, and new products put on the market for well over a hundred years now.  The market is mature, and may well be considered saturated.  Please keep us informed with what you end up with.  There is always room for a better product at the right price.


----------



## strantor (Jan 11, 2019)

Bob Korves said:


> different point angles, different twist rates of the drill, and what the drill is intended to be used for, all come into play and require changed settings for best results.


This is where all the knobs and axes and adjustments of the commercial sharpeners come into play. I don't want all of that confusion in my design. I can teach my guy to recognize standard jobber bits (95% of what's in my bum bit bucket) and "anything else." "Anything else," I can sharpen myself.


----------



## ddickey (Jan 11, 2019)

I'll pay you to take my Drill Doctor.


----------



## strantor (Jan 11, 2019)

Bob Korves said:


> There are at least dozens, if not hundreds of differently designed drill jigs available on the new and used market, from under $5 to thousands of dollars.  They all work if used properly, some better and more quickly and easier than others.  Drills are used in many industries and in many home shops, so there is a huge market, but it is already pretty saturated with products that do the job if the operator does his job correctly.  Drills can also be ground to a proper point without any jig at all, just eyes, brain, tool rest, and bench grinder.  It is done all the time, some far better than others.  I grind all my drills 3/4" and above by hands and eyes to a good result, checking them with a drill gauge.  Drill bit grinding tooling has been studied, better mouse trapped and improved, and new products put on the market for well over a hundred years now.  The market is mature, and may well be considered saturated.  Please keep us informed with what you end up with.  There is always room for a better product at the right price.


Perhaps I'm putting the cart before the horse. Perhaps my first step should have been to ask around on this forum about commercially available drill sharpening solutions that fit my requirements. If what I want is already for sale, I would be more than happy to pay for it. Here's what I need (in order of importance):
1. operable out of the box by someone who knows little to nothing about drill bit geometry and has no technical intuition (but can follow simple instructions).
2. Produces repeatable and accurate results
3. Fast one-step or no-step setup change, going from large bits to small bits and back again.
4. Extremely simple interface, very few adjustments. Even if only suitable for sharpening general purpose bits; that's fine.
5. Decent quality, American made preferably


----------



## benmychree (Jan 11, 2019)

Just buy the damn Drill Doctor already!  I had one at my shop, and nearly anyone can learn to use one quickly and accurately they have very few adjustments necessary, mostly the one for spiral angle of the drill flutes; if you are using ordinary drills, likely no adjustment is necessary.  I he one that I had also did split points, which makes drilling more accurate and faster with much less feed pressure being necessary.


----------



## strantor (Jan 11, 2019)

benmychree said:


> Just buy the damn Drill Doctor already!





ddickey said:


> I'll pay you to take my Drill Doctor.



Ok does $5 sound reasonable? I'd accept $5.


----------



## strantor (Jan 11, 2019)

benmychree said:


> Just buy the damn Drill Doctor already!  I had one at my shop, and nearly anyone can learn to use one quickly and accurately they have very few adjustments necessary, mostly the one for spiral angle of the drill flutes; if you are using ordinary drills, likely no adjustment is necessary.  I he one that I had also did split points, which makes drilling more accurate and faster with much less feed pressure being necessary.



The reviews I've read are very hit-or-miss. I don't if it's QC or model-dependent, or what. People either love them or hate them. I think it comes down to whether the Dr. "speaks" to you or not. Plenty of mechanically intuitive people can't make the contraption work. I've not tried it myself but maybe I will. It costs less than the week of minimum wage I'd have to pay for my own contraption to be built, so probably worth the experiment. What model do you recommend? Also, is there any way to dress the grinding wheel or does it have to be replaced? I'm talking about probably 50lbs of bits here, of all sizes.


----------



## mikey (Jan 11, 2019)

I own a Drill Doctor. It works well for me and if I can use it then pretty much anyone can. The how-to is on video so I don't see how you're going to mess it up. It uses replaceable diamond wheels to sharpen the drill with so you will need to change it when it dulls. It tends to overheat the drill when it dulls so you'll know. I changed my wheel once after about 20 years of hobby shop use. 

You put a lot of thought into your design but I would just buy a DD and move on to more important things.


----------



## ddickey (Jan 11, 2019)

I have heard people having good luck with their Drill Doc. Not me.


----------



## bhigdog (Jan 11, 2019)

The only thing wrong with a DD is it's too light. If it was heavier it would make a good boat anchor...................Bob


----------



## cathead (Jan 11, 2019)

Long ago, way back in olden days in a time before all these contraptions and doohickeys existed, machinists simply used a grinding
wheel to sharpen their drills and it wasn't a problem.  Maybe try learning a new skill and try off hand sharpening.  It's really not that
difficult to do.  I use a disc sander for sharpening but a grinding wheel works too.


----------



## strantor (Jan 11, 2019)

cathead said:


> Long ago, way back in olden days in a time before all these contraptions and doohickeys existed, machinists simply used a grinding
> wheel to sharpen their drills and it wasn't a problem.  Maybe try learning a new skill and try off hand sharpening.  It's really not that
> difficult to do.  I use a disc sander for sharpening but a grinding wheel works too.



Yeah I get it. I did that. I can hand sharpen drill bits. I'm not great at it and I'm not fast, but I can do it. With more practice I could get better and faster. But I have a business to run, and no matter how fast or good I get, I won't be able to justify my time sharpening drill bits. I could forward your advice to my helper and make it a job requirement to teach himself to sharpen bits, but even at minimum wage, I can think of better uses of his time. He's burned up two days already "learning" how deform HSS with a grinder. At the end of the day, all I need is bits my bits sharp. Well I need more than that, but you know what I mean. I'm responsible for making that happen indirectly by whatever means.


----------



## madmodifier (Jan 11, 2019)

So much dislike of the drill doctor. I have a 750x and I think it does a pretty good job. It will not however fix the crappy steel in import drill bits. As long as you are working on under .750 drills they are an OK way to go imo.


----------



## strantor (Jan 11, 2019)

madmodifier said:


> So much dislike of the drill doctor.


See what I mean?


strantor said:


> The reviews I've read are very hit-or-miss.... People either love them or hate them.


This is what I was talking about...




Bob Korves said:


> Drill Doctor... works very well after you understand how it works





Liljoebrshooter said:


> Why not try a drill doctor? I don't have one but have heard they work pretty good.





ddickey said:


> I'll pay you to take my Drill Doctor.





benmychree said:


> Just buy the damn Drill Doctor already!





mikey said:


> I own a Drill Doctor. It works well for me





ddickey said:


> I have heard people having good luck with their Drill Doc. Not me.





bhigdog said:


> The only thing wrong with a DD is it's too light. If it was heavier it would make a good boat anchor


----------



## Bob Korves (Jan 11, 2019)

It is not really so much that the DD is difficult to use, or that many operators have trouble with getting good results with it, or indeed with any other drill grinding machinery.  It is about learning how a drill is made, in detail, learning about the geometry of a drill, in detail, learning how the machine they have in front of them does the work of grinding the drills, in detail, and also understanding, in detail, how changing one part of the setup changes some or all of the others.  Then, going to work at learning how to deal with variations of various kinds of drills, in point angle, clearance and relief angles, flute helix angles, and web thickness.  Beyond that, what alloy the drill is made of, and how it interacts with various work materials -- and the properties of those materials.  It is really necessary to know that information -- and how it changes the way the drill cuts -- before you can apply a well thought out plan for what drills to purchase; making drills sharp again; maximizing production while making holes within tolerance for size and for surface finish (if required) -- at the highest possible cycle rate and with a near zero rejection rate.  Some times it makes more sense to just use new drills until they get to a certain amount of wear and then just toss them.

Of course, I morphed on purpose into writing about how things work in large production plants rather than a small job shop, much less a hobby machinist shop.  But really, that is who you are often in competition with if you are doing commercial work.  You might be doing jobs with far less quantity for a local clientele, but working smart and efficiently, and having happy customers, is still what wins the game.  One "OH ****" cancels out MANY "atta boy's" in business.  You must be smart, skilled, involved, efficient, and a people person.

All that is why I am nearly always the only person in my shop, and is also why I only have to deal with myself...


----------



## strantor (Jan 11, 2019)

Bob Korves said:


> Some times it makes more sense to just use new drills until they get to a certain amount of wear and then just toss them.


That's what I've been doing all along, hence the bucket of reject bits. It's never been worth my time to sharpen them. I thought now that I have a helper, it would be worth his time (my money). So far it's not. There's only one person around to teach him, and that's me. If I stop my billable work to teach him, I'm losing more money than if I just did it myself (his pay *plus* my pay). And I can't even mentally write it off as an investment in training, because the tutoring he would get from me would be subpar. I've been leaving it up to him to learn on his own from YouTube but I don't think he has to intuition or maybe the experience to pick it up that way. 

Everything you said after the "_in detail_" punctuations, has me thinking that maybe I need to just keep filling the bit bucket and revisit this later. Once my helper learns how to actually _drill_ a hole, what bit to use, what speed to use, etc. then he'll be ready to learn to sharpen drills. This guy put my trailer's lug nuts on backwards. Me asking him to sharpen drills is like a chemist asking me to keep his lab stocked; I don't know what any chemicals are or how often they're used or anything.


----------



## mmcmdl (Jan 11, 2019)

I'm just not sure what to think of this !  ( other than I have a knife sharpener like that )


----------



## ddickey (Jan 11, 2019)

The big problem with a DD is the collet that holds the bit. As you tighten the collet the bit turns slightly. Very annoying.


----------



## coffmajt (Jan 11, 2019)

Have you looked at gadgetbuilder.com website = there you can find a four facet drill sharpener that will sharpen up to .5 inch diameter bits and is simple to use (not necessarily to make)  Just more ideas to consider


----------



## P. Waller (Jan 11, 2019)

If you are going to go through the work of adding human figures to a rendering at the very least give them eyes.
Or at least title the thread "featureless humanoids using a tool" (-:


----------



## strantor (Jan 11, 2019)

P. Waller said:


> If you are going to go through the work of adding human figures to a rendering at the very least give them eyes.
> Or at least title the thread "featureless humanoids using a tool" (-:


It's sketchup. Each time you create a new model they drop this faceless creep "josh" into the center. My first step is usually to delete him but I decided to keep him around for scale this time.


----------



## mmcmdl (Jan 11, 2019)

strantor said:


> This guy put my trailer's lug nuts on backwards.



 Good candidate for a desk jockey !


----------



## strantor (Jan 11, 2019)

mmcmdl said:


> Good candidate for a desk jockey !


If I had 40hrs/week of papers to push, I'd have him on it. He's a good kid, hard worker and very eager to please. But he grew up without a masculine influence and knows very little about anything. He has no problem getting his hands dirty changing axle bearings, but until I told him to change them, didn't know axles had bearings or what they were for. There are a lot of "training moments."


----------



## strantor (Jan 11, 2019)

coffmajt said:


> Have you looked at gadgetbuilder.com website = there you can find a four facet drill sharpener that will sharpen up to .5 inch diameter bits and is simple to use (not necessarily to make)  Just more ideas to consider


I don't want to forget to reply to this. I'm still browsing that site. Lots of information, hard to not get side tracked. Thanks for the suggestion.


----------



## mmcmdl (Jan 11, 2019)

I own a kid like that !  Very very smart , makes damn good money , couldn't give a good crap about anything mechanical ! ( I taught him well )


----------



## jdedmon91 (Jan 11, 2019)

this is my SRD drill grinder. Thought I’d throw a picture of it in


Sent from my iPhone using Tapatalk


----------



## hman (Jan 12, 2019)

P. Waller said:


> If you are going to go through the work of adding human figures to a rendering at the very least give them eyes.
> Or at least title the thread "featureless humanoids using a tool" (-:





strantor said:


> It's sketchup. Each time you create a new model they drop this faceless creep "josh" into the center. My first step is usually to delete him but I decided to keep him around for scale this time.


Aw shucks, fellers ... at least Josh has a mouth ... which is more than you can say for Dilbert.


----------



## projectnut (Jan 12, 2019)

I purchased a Drill Doctor Classic like this one over 20 years ago:
https://www.drilldoctor.com/dd750classic.html

It worked fine for about 10 years, then started to show some wear.  At the time I was sharpening around 50 drills a month.  Over time the wear got to the point it took more time to do a setup than it was worth.  

A friend of mine had a Black Diamond grinder setting in the back of his commercial shop for around 5 years.  He bought it as part of a lot from a National Guard repair depot when they were closing down.  He never used it and offered it to me for a reasonable price a couple years ago.  It's a great machine and took all of about 5 minutes to understand how to operate it.  Since purchasing it I've managed to sharpen most of the drills that I had been throwing in the drawers since I was too cheap to throw them away and too lazy to spend the time to sharpen them on the Drill Doctor.

In all I think I've sharpened around 500 drills ranging in size from #52 to 3/4".  It takes about a minute to do each one, and when finished they cut better than they did when new.  The machine is so easy to operate I don't mind taking the time to sharpen a drill even in the middle of a job.  With the number of drills I purchased during the time I wasn't using the Drill Doctor I think I have enough to last a lifetime. 

Here's a couple pictures of the Black Diamond Drill Grinder.  They are outrageously priced when new, but there are a number of good used ones on the market for a more reasonable price:


----------



## ddickey (Jan 12, 2019)

Over seven grand new. This is one serious drill bit grinder.


----------



## projectnut (Jan 12, 2019)

ddickey said:


> Over seven grand new. This is one serious drill bit grinder.



 It does have a serious price tag if purchased new, but then again it was probably cheap as far as the military was concerned.  If you remember this was the era when they were paying $500.00 for a toilet seat and $700.00 for a hammer.  On the other hand I paid only slightly more for it than I did for my original Drill Doctor.  It came with a nearly complete set of collets, and a spare wheel.

It's a bit of an oddity in that it has a 220 volt 3 phase 1/3 hp motor.  That was probably intended to deter theft.  Too bad they didn't check the power requirements before they bought it.  The shop it was purchased for didn't have 3 phase power.  It sat in a corner unused since 1974.


----------



## rwm (Jan 12, 2019)

I would sell you my drill doctor but I AM using it as a boat anchor...
If you are trying to grind something to within a couple of thou you can't make the machine and holder out of flexible plastic.
Robert


----------



## rock_breaker (Jan 12, 2019)

Can.t resist getting into this! I have an Enco Tool Grinding Machine that I believe is similar to a surface grinder and in the attachments for this machine to sharpen drill bits is a picture of the tool Bob Korves used in his post. I inherited a similar tool 30 years ago and have found it to work quite well once I learned how to use it. 
Basically I place the bit in it with the cutting edges as near vertical as I can, then rotate it counter clockwise to grind the face on one side of the bit alternating faces with the same depth adjustment as I go. This requires that the "swing" is greater than 90` so that the bit can be placed close to the stone so it will grind the cutting edge straight up and down. The tool grinding  machine facilitates setting the bit as close as required
A note about grinding on the side of the stone. I used this set-up using my bench grinder long enough with out changing the stone until I noticed the stone was showing a taper due to bit sharpening. Sharpening on the side of the stone will require occasional trueing of the side, not having tooling to do this I changed stones.  
Have a good day
Ray


----------

