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[line through the center of the spine]

I have recently sharpened the blade of a metal hand planer, which is a look-a-like of a Stanley single iron bench plane SB3 (just to make clear what I talk about). The blades are hardened (HSS), so the standard SG stone will take hours. I used a F120 corundum stone for the coarse work and a SiC stone to make it finer.

Since chisels and similar blades have a flat upper surface, the WM-200 angle tool works fine for that. The recommended grinding angles for those blades are between 20-30 dps (although there is only one side to be sharpened). The blade itself is angled at about 45° from the working surface, which leaves several degrees of relief behind the cutting edge. In my case the bevel is down.

Spoiled by sharpening by numbers, I looked if setting the angle by T-USB was feasible, which would allow for grinding and honing at a precise angle, just as it is customary todays for knives.

All associated programs ask for the jig diameter. They were obviously developed with knife sharpening in mind, so they silently assume a symmetrically round jig (at the spot where it rests on the USB at least). All past knife jigs fulfil this demand, and the diameter was chosen for simplicity and convenience.
The real value of interest however, is the distance from T-USB to the imaginary center plane that is constructed by the line through the center of the spine (of a knife) and the cutting edge (let´s call this the center plane for the lack of better words).

This is the parameter the program works with, because this distance is a crucial part in constructing the triangle that spits out the T-USB-to-stone value we are after; on a standard knife jig it comes out as 12 mm / 2 = 6 mm.
The graph here Calculations used for calculating SVM Knife Projection displays those relations quite nicely.

But note, this is a source of error: the older models of the knife jig used to have a 12 mm metal bar and thus a consistent diameter throughout. They had the potential of non-symmetric clamping, which would lead to uneven bevels. Its current successor was made symmetric, but has an inherently variable bar size due to its construction. Using it at the outmost rest will indeed yield 12 mm, but on the inner rest, for smaller knives, it will be more like 14 mm. This introduces an error probably overseen by many.

Fortunately sharpening of knives is not rocket science, a fraction of a degree up or down won´t hurt as long as the settings are consistent, repeatable and symmetric, but keep that source of error in mind particularly if you are the nit-picking type.

I used the SE-77 SE-76 square edge jig (in case this has changed over the years: I speak of the model ca. 2007) as a test candidate. The parameters needed for the program(s) are not obvious or readily measurable, so I looked into that.

The first parameter to determine is jig diameter. As mentioned before, the internally used value is the distance from T-USB to the center plane. In our case, the latter coincides with the top of the blade (there is no second blade side and there is no upper half of the jig rod). Consequently the choice for naming this parameter "jig diameter" turns out to be an unhappy one, but that´s how it evolved. Let´s call this real parameter center plane displacement for the exercise.

For the SE-77 square edge jig center plane displacement comes out as 24.5 mm 25 mm (see fig.1 "measuring center plane displacement"; measure the distance from the top of the blade to T-USB using a vernier). This is straightforward. This number is invariable and only needs to be determined once for a given jig.

According to the above explanations, this is only half of what the jig diameter parameter expects despite the fact that it internally works with exactly that number, so you have to enter double of that value, i.e. 49 mm 50mm. (Being taken for granted, this parameter accordingly does not receive particular attention in the above drawing. It is denoted by a circle around the cross-section of the USB.)

One more measurement we need is projection. Projection is defined as the distance between the point where the center plane meets the stone and a plane that is in a 90° angle to it that touches the USB bar at the stop screw (let´s call this stop screw plane, see picture). This is a bit tricky to measure. (Note that neither the jig axle's rest nor the jig stop's contact point are necessarily meeting T-USB. They are different points, but close. Refer to above mentioned graph). Thus directly measuring the distance from the USB's rear side to the cutting edge in parallel to the center plane with a vernier is not yielding the right result, since the SE-76's flanges protrude towards the operator and obstruct any direct access to the USB with the caliper's feeler fingers.

See fig. 2 "measuring stop screw plane to rear jig offset". Place a try square flush to the top of the jig. (Left or right of the stone the jig can be flipped forward or backward and stay put in a resting position). Its one leg is in parallel to the center plane. Measure the distance from the inner edge of the other leg to the USB with the vernier.

It turns out that this offset is exactly 5.5 mm 5.3 mm. (Again, measured on my older jig). The intermediate projection value measured with the caliper was 70 mm (See fig. 3 "measuring the intermediate projection value": use your vernier to measure the distance from the cutting edge to the rear side of the jig. Aim to be in parallel to the center plane), so the correct projection is 70-5.5 70-5.3 = 64.7 mm.

I chose to grind at 27.5 dps, and the T-USB value produced by the program is 26 mm (rounded) 25.9 mm (note: this is only valid in conjunction with the current diameter of my wheel, 198 mm), which is much smaller (about factor 3) than what one may expect for knives due to the much smaller projection.

I sharpened with this value, and after sharpening I checked the edge against the angle gauge notches on the WM-200 (fig.4: "controlling the final angle"); it fits perfectly into (one half) of the 55° notch. So this is another proof that the number method works universally.

A small appliance akin to the ones existing for knives could be made to mount the planer blade at a certain projection every time, in which case one could work with the very same setting over and over until the wheel diameter has changed. Even thicker or thinner blades would not make a difference, since the jig opens towards the bottom.

I later sharpened a plain chisel with the same method. Without going into detail (since the basic procedure is well documented), the angle turns out correct.

Have fun.

Edit: I updated the jig dimension measurements above after finding a more exact method.

[John Juranitch]

This is a description of a jig I made for sharpening axes. Nothing speaks against using it for cleavers or other blunt instruments too, but I have not tried it. I hope you will.

If there were a subforum for axes, then I would put it there, but there is none.
Using it for cleavers however justifies its relationship to knives.

Tormek´s jigs for knives clamp the knives on the spine, hopefully symmetrical around the center to achieve symmetric bevels. Using the available knife jigs, a given knife in the jig gives a projection distance of some 10-15cm, and that´s what the whole system is set up for.

With a chosen grinding angle, this results in a certain T-USB value. All available calculators spit out the corresponding value. So far so good.

Unfortunately there is no jig commercially available that clamps an axe in a comparable way.
There are many ways an axe could look like on its butt, many shape it could take on, and there could be huge variations in thickness. A jig like the knife jig that grasps from the back would most certainly fail.

The projection would become enormous, and T-USB with it. The attempt to use their huge support bar is a palliative measure and does not necessarily touch the problem. The axe jig clamps, but does not help much otherwise.

So I thought, what clamp is adjustable? A screw clamp. It even has a pressure plate that can adapt its angle to the surface with its ball-bearing like holder and thus always stays put.

Unfortunately the other side of such a clamp is fixed. So I bought two of them, and out with the angle grinder, and I mounted the two adjustable halves facing each other with a common spine like shown in the picture below.

For the axe shown, I clamped the jig approximately at the center of the circle the cutting edge describes, or slightly behind that (see later). This lets you pivot around that point. I used the known techniques of lifting and pivoting.

If you take care, the axis of the two screws (resp. the rod) is perpendicular to the axe´s surface, which will guarantee symmetric grind. The two screws function as a pivot point, and the axe becomes the jig. The double clamp grips perfectly, particularly if you have the spine flush against the axe´s butt.

This contraption has several similarities to a knife clamped in a knife jig:

• short projection
• symmetric clamping
• all calculators work

I used the usual calculator, but with a slight change. The calculators work with the center of the jig plane, and they half a given diameter automatically. So haul out your calipers, measure the axe´s width at the clamping point (in other words: the distance of the pressure plates) and enter that value in the position where the "jig diameter" value goes.

When grinding the traditional way (with the stone rotating towards you), you have a certain downwards tilt, just as you would with a knife. Now with the c-clamp jig (I call it the Bessey jig) the USB´s horizontal rod rests against the clamp´s screw (see picture below). The USB bar may initially rest against the pressure plate, but soon before long it will slip over the pressure plate´s rounded edge and find its final destination at the screw. So take care that you always rest against the screw and not the pressure plate when you are changing sides.

Acute readers will notice that this changes the angle, but I found that the angles come out right (gauged with the notches on the angle master) when you measure the axe´s width inclusive the pressure plates at their top. Because that´s the surface the USB finally rests upon.

I made two axes so far. According to John Juranitch´s advise, I thinned down the region behind the cutting edge somewhat. I also polished this relief with a JIS1000 stone, which is more of a cosmetic thing probably. I did not polish the cutting edge. As you see, it holds up nicely after a fair rake of hardwood at a 40 deg inclusive angle.

This jig costs very little and does not require any additional expensive accessories or any contorted postures by eliminating large projection distances.

For the axe shown, the projection distance was 148 mm. At a 20 dps angle the resulting T-USB value was 96 mm. This is fairly at the limits of what the USB can be pulled out (I can only speak for a T‑3) but would come down if I had chosen clamps with a larger depth. The clamps´ depth is 50-60 mm. Next time I get a pair of larger ones. Note the axe it not rusty as it may appear, this is painted with linseed oil, as is good practise.

I can see that this works on cleavers too. The length it grips "forward" just depends on the depth of the clamp you choose. For a cleaver, the depth of the clamps used would probably be perfect.

And don´t forget to reset the jig diameter parameter after use.

(please excuse the less than stellar photographic skills. This is not an art contest.)

[different environment parameters!]

Most hobbyists like me (until recently) don´t view a drill (drill bit as the American call it) as something special. But this is not the case. There is a lot of brainpower behind it.
After looking into this matter deeply, I no longer view drilling as a simple task, but rather as an art form. To be able to quickly apply the optimum grind to a given task is certainly the supreme discipline, but this assumes a firm understanding of the subject. So even the latter alone is empowering.

I write all this down in the hope that it may speed up somebody´s learning curve and that It may serve as a thought provoking impulse for further investigation. 
The following reflects the apex of my insights and investigations on the subject up till now and is by no means claimed to be universally valid or true or free of errors.

---------------

Grinding  Four-facet (hereafter: 4F) drill points has the undeniable benefit of being within the realm of the home sharpener since the introduction of Tormek´s drill sharpening jig;  and while this grind may alleviate some problems, it is not the end of all those problems, although the impression is fostered.

With 4F the chisel, the non-productive area at the center where the web resides is reduced by half, but it still exists and it is the cause of wear, heat generation and drill walking (although reduced).

Mazoff is a famous promoter of the 4F grind, and so is (naturally) Tormek.
Both report similar increases in service life, but neither of them reveals the surrounding parameters.

As briefly hinted above, the weak point (literally) of the 4F grind is the region around the web. Like the standard conical point (SCP hereafter) it does not cut – it extrudes, although it is smaller than on a standard conical grind. Indeed I looked at a freshly ground small drill (6mm) with the enlargement glass after a drill session and noticed the cold-weld bead on the point coming from extrusion... This region is naturally marred first.

Both of those grinds´ center regions will run hot eventually. Now this is poison for trying to cut stainless steel. Before you realize it, hard alloy components from your drill metal migrate to the parent metal, and the piece of stainless steel turns out harder than your drill is. It will run blue and even the best and freshly 4F ground drill can fail within seconds, making it a candiate for the bin.

It would seem that a cutting point like a conventional split point (hereafter: CPS) would eliminate that problem, and to an extent it does, but the downside is, that this faces you with yet another grinding challenge.

Honorable members of the scene like ,,Gadgetbuilder" John Moran think, that CSPs or similar measures are only necessary for bigger drills (say from 12 mm upwards), while he thinks that small drills perfectly get along using a 4F point.

But there is a different, equally valid approach that came to my ears:

My brother-in-law works in a factory making balconies and fences out of aluminium and stainless steel (wooden balconies being almost extinct). They use small drills like 3.1mm (for some reason)  for pre-drilling, and those do employ a CSP grind. They swear by them. Those bite into the parent metal more readily and thus reduce the risk of burning. They also have a limited tendency to walk. None of the drills they use hereafter are split. They don´t see the purpose for splitting them.

Moran again, in total contrast, advocates the use of a small drill (like 5mm) ground with 4F for pilot drilling. To be precise, he prefers spotting drills (ground to a very flat angle) over center drills to eliminate chatter and walking. Link.

So what is going on here? The answer is: different environment parameters! The prior clientele mainly uses drill presses and hand drills, the latter speaks of lathes resp. NC machinery (where Moran comes from) that have a very tight grip on both parent material and drill.

Furthermore, Mazoff in his well-known article tells us that his modified split point (hereafter: MSP) yielded much bigger service life than other´s, which will be true beyond doubt, but what did they use it for? Cast iron cylinder heads? Those are notoriously bad to drill even with pilot holes I heard.

We cannot view the performance of a drill (or rather a drill´s point geometry) isolated from neither the parent material nor the machinery.
The logical conclusion to this is that none of the grinds provides the final answer to all cases. Nor can the service life be attached to a certain grind indiscriminately.

Before I came to all those conclusions, I tried to apply my artistry to the Tormek. I modified the jig somewhat and managed to successfully grind something probably akin to Mazoff´s MSP (after many failures...). I can elaborate on this if there is a demand.

This can be applied to 4F (although with the relief facet only ground to where the corner meets the web rather than up to the center) and store-bought SCP´s. They work well into virgin parent metal, but apparently no better than using a pilot hole with a stock SCP.

That all said (and John Moran has come to the same conclusion eventually) you may instead want to equip bigger drills with secondary point angles (SPA, see Mazoff). I find that those much reduce the tendency of drills to block upon break-through on the bottom side of the parent metal.

SPA´s can be realized easily and faithfully on the DBS-22 with a slight modification of the sled (shown elsewhere here). Being cutting edges, they eventually need relief, but not if you keep it decent. John Moran told me this upon a private contact.

So the upshot is, for a hobbyist sharpening with a Tormek (and this unit is no doubt geared towards the advanced hobbyist), particularly if you mainly drill mild steel or stainless by hand (or drill press), you do not desperately need to equip big drills with a CSP (or similar), but you may want to invest into a pack of high quality drills with a split of sorts for piloting (you cannot grind a split point onto small drills with the Tormek). While you are in the shop, you may also get a specimen of a precision center punch.

Alternatively, a 4F small drill (such as 5mm) may serve well for this purpose too.
(Note that Moran grinds smaller drills without relief facet and that very small drills cannot be ground at all on the Tormek without additional gadgetry).
You may want to consider applying SPA´s to bigger drills, such as from 10 mm upwards.

Note that Mazoff goes on at length that that the influence of point angles and relief angles on the result may have a much greater impact on the performance than the point geometry itself. I recommend studying his essay ,,Drill Point Geometry" in depth.

Non-iron material must be investigated separately, and to my knowledge no mention has been made as to the relevance of 4F to those. That said, I have read that SPA´s are known to be beneficial particularly on plastics and thin sheet material.

One thing that has not been touched upon yet is the general aspiration level concerning drills. A company may have as one of their goals that a maximum number of drill operations per time slot are completed. Mazoff obviously comes from that corner, he clearly speaks for large scale manufaction where every second translates into money. So the necessity for pre-drilling may mean a loss of time that cannot be disregarded. On the other hand, a manufacturer of drill bits themselves may skip any web thinning action in favor of shorter (read: cheaper) time-to-market.

Again for the hobbyist (particularly of the model maker type), I guess quality may be the main aspiration, but I know many car tinkerers that could care less about precision and just want a hole done, period.

This is another perspective, from which we may have to view the discussion.

Edit:
Another facet of the subject (pun intended) might be worth considering: the experiments quoted by Mazoff and Uddeholm are no doubt executed under controlled environment conditions. In practical terms this means for example: a rigid drill press or similar, controlled feed, controlled speed, controlled thrust, controlled cooling and lubrication, a certain type of material and probably more. The kind reader will immediately recognize that none of that can be met by a layman. I leave it up to you to decide how meaningful such tests can be for practise.

[John Juranitch]

Now this subject is not entirely sharpening related, but it is knife related. As such it would fit into a forum like the sadly defunct kitchen knife forum, but due to the technical relation it also fits perfectly into the league of spreadsheets available here vor diverse sharpening calculations.
This may be a nice-to-have addition to your box of tricks.

I recently read the sharpening book by John Juranitch, The Razor Edge Book Of Sharpening. On page 43f. he speaks about steeling your edge. He explains, why using a (sharpening) steel keeps the knife sharper for much longer. We all have seen cooks wielding this item with the knife, and I always thought, either they are so incredibly good or they are showing off. Maybe both.

A leisure time cook on the other side, will have his problems with this device. I do not exclude myself from this (until recently at least). The crux is that a certain angle, coincident with the grinding angle, has to be maintained during this action. What makes it worse, is that nowadays you easily have at least two knifes with different grinding angles in your arsenal.

Juranitch invented this crafty device (shown on pictures 2-4 to 2-6) that rests with on a base on the table and has some reverse cone on the tip that serves as an angle guide to give your muscle memory a firm idea.

In recent publications I have seen a similar method advocated (bar the cone), using a stock sharpening steel with a handle in the left hand, with the tip down on some rag between it and the table, which securely locks the device. You may want to look up the book if it is not clear what I mean. (The book is available for free in one of the archives.)

Unfortunately the cone method relies on a single grinding angle. Actually, to be more precise, the angle guide determines a certain angle.
If one wished, a cone like that could be easily done with a 3D-printer nowadays, but this would again limit you to the angle it was designed for.

Now you´d be happy if a typical hobby cook or a housewife cared about their knives at all, letting alone such fine details. I am sure, if they were educated, they would be happy to use a steel. With the aid of a lookup table this would be very easy indeed.

One of the beginner sharpening instructions recommended to use a set of coins or an angle wedge or whatever contraption to raise the spine of the knife reliably and repeatably far enough to achieve a certain angle.
In the wake of this I saw a lookup table that gives a discrete number instead by using two parameters: knife body height and sharpening angle.

Now this very table can equally be applied to using a sharpening steel.
When I saw the program by forum member jvh I knew that I had to incorporate this into the program. The table is static, so it is ideally suited to printout.

I took the liberty to use jvh´s visual appeal and table functions; they are nothing less than perfect. The underlying geometry is nowhere near as complex, so no intent to compete with him. The table has been verified against the one I found on the internet for sharpening. Thanks jvh for the great job.

The table is locked to avoid unintentional changes, but has no password.
You can adapt it to your needs any way you like.
This method is nowhere near scientific, but gives you a much better starting point than being clueless.

Have fun,

-Helmut

And by the way... this works for your unobtainium strop too...

Greetings,

I am in the verge of upgrading my cooking utensils with a Japanese Knife.
Edit: knife information updated.

As different to most of that league offered in Europe, that one, although being a double edged knife,  is ground asymmetrically at an unknown percentage.

This site (and others) recommends for sharpening:

If the double-edged kitchen knife is a symmetrical 50-50 V-shape, you will apply a similar number of strokes on both the front and the backside of the blade. However, if the front face has more edge than the backside such as in a 70:30 double-bevel kitchen knife, you will apply 7 strokes at the front and 3 strokes on the knife's backside.

This approach suggests equal angles on both sides, but on some other web page I have seen actual different angles specified for the respective sides (unless this procedure results in different angles, which I fail to comprehend).

The shop on the beginning mentions (in the blog somewhere) that the grind can of course be overridden with a standard 50/50 grind, but they surely have had some intention with that. (That said, it may not make a big difference.)
Edit: they have...

Masahiro's edge is its most important feature. The edge is 80/20 asymmetrical, rather than sharpened equally on both sides. The idea being that the asymmetrical edge is 35% thinner than a 50/50 edge. This fact makes Masahiro's knives sharper than other Japanese knife brands.

(Source)

We have learned that a primitive knife jig or a wrongly clamped knife will produce such a non-symmetry, albeit as an unwanted side-effect and probably vastly unpredictable let alone controllable.

Does anybody here have experience with such knives? Has anybody worked out a solution other than nerve-wrecking re-adjustments on tasks like de-burring? I found no reference to this neither here nor there.

Thanks,
Helmut

[Gadgetbuilder]

As a follow-up to my thread on 4+facets and SPA´s and fuelled by Rick´s Mission I´d like to speak about my findings regarding SPA´s.

I suggest reading Mazoff´s document (which has been quoted countless times here) if any of the following terms sounds non-familiar.

After making the mod Rick suggested to the jig´s baseplate, which worked perfectly (thanks man), those questions arose immediately:

• do I need SPA´s at all?
• how much SPA do I grind?
• at what point angle?
• at what relief?

Gadgetbuilder mentions in his great building document ZIP file containing the sharpener plans

(...)claimed by Joseph Mazoff in his "Drill Point Geometry"[1] document. Adding Secondary Point Angles (SPAs) improves the drill's self centering tendency, improves hole finish, reduces drill wear, and reduces the exit burr when through drilling.

So let´s make it clear before we start, this statement of Mazoff is what everything goes back to. Apart from seeing SPA´s appearing on some drills, we have no evidence other than his claimed experience. I don´t think we have reason to doubt, but let´s agree that this is momentarily a claim.

That settled, Gadgetbuilder´s experience seems to support the claim:

Both split points and SPAs help to reduce wander when drilling deep holes.

and

These extra facets cause the drill to have a stronger self centering action and the sharp outer point on the cutting lip is eliminated so the drill remains sharp longer. The chip is weakened by the difference in cutting action between the primary and SPA facets so long spirals are less common because the chips are prone to break. (...) When through drilling the SPA reduces or eliminates the exit burr on most materials.

but now comes the caveat:

Secondary relief can be added to the SPA but isn't necessary for small SPAs.

Photo 13 shows an 8 facet drill with large SPAs, so large that secondary relief was needed for the SPA -- and even that wasn't enough. This drill was tested by drilling several holes in 1/2" mild steel, which produced heat discoloration in the heel area from rubbing. Hand grinding this area could eliminate this contact but instead I use smaller SPAs since they increase drill life without the hassle of hand tweaking the heel.

SPAs can improve drill performance or, as noted above, can degrade performance if too large so work your way up in SPA size.

Gadgetbuilder´s resumé on the claims was:

The 1/4" drill I experimented on cuts steel nicely but it is impossible to evaluate whether all the claimed benefits are actually realized without conducting a controlled experiment. However, it is easy to do and works well so I commonly add SPA facets to drill bits - mostly bits larger than #25 since smaller bits usually cut well even without an SPA.

Drill # 25 is IIRC something not far away from the smallest drill the jig can sharpen, so this practically concerns all of our drill sharpening tasks.

So my momentary answers to the above questions are:

• maybe not exactly need, but helpful on larger drills
• better too little than too much to start with. Time will tell. Unfortunately no cook-book recipe for this.
• the point angle was never mentioned, but since it is an extension of the primary cutting lip, I presume: the angle chosen for the task (setting "P" on the jig).
• none for small SPA´s, secondary relief for bigger ones. Angle assumed equal to setting "S" on the jig.

For starters, I would leave it away. It is unclear, if any assymetry would impair the drilling action resp. how tolerant the drill is towards imperfect SPA grinds.

Experience welcome.

[4-facet grind plus SPA´s]

I would like to bring up some subjects, but since there is tremendous uncertainty about the terminology of 6-facet grinds I would first like to clarify that.

There is no consensus as to what a 6-facet grind is. Some think it is a 4-facet grind plus SPA´s (and indeed Mazoff in his well-known article speaks of a 6 faceted drill with secondary point angles (SPA) which could be interpreted this way), but others speak of added relief facets extending the primary and secondary relief planes by a even steeper relief plane, sometimes called tertiary.

The 11/32" drill shown at right has small SPA's added making it 6 facet.

( GadgetBuilder alias John Moran on Drill Sharpening Etc, chpt. ,,Honedrill")

An article by Derek Brown appeared in Model Engineer issue #4025 describing some additional jigs for the Quorn to facilitate "6 facet" sharpening. This process extends the 4 facet process, adding another secondary relief (ternary relief?) at 45 degrees, again arranged so all intersection planes meet precisely at the drill axis.

(Ron Chernich on Drill Sharpening On The Quorn chp. "Six Facet Sharpening")

Four facet drill sharpening (...) Secondary Point Angles (SPAs) can be added to extend drill life, improve hole finish and minimize the exit burr on through-drilled holes.

( GadgetBuilder alias John Moran on Drill Sharpening Etc, chpt. ,,A Powered 4/6 Facet Drill Sharpener"

So by now it should be clear that SPA´s are not limited to a certain sort of grind.
Neither are methods for web thinning like splits.

The point can be split on 4 facet or conical drills.

( GadgetBuilder alias John Moran on The Home Shop Machinist post#8: "4-facet" vs. "split-point" drill grind definition)

(Note the great compilation by Arthur Marks in the end of this document.)

I will address both subjects individually in following threads shortly.

Having that cleared, I would like to bring the tertiary facet to your attention.
Ron Chernich mentions this extra facet in the link given above, but he is not very clear on the purpose of this added complexity.

The secondary relief is commonly said to be about 20° (Chernich: 25-30°). I believe this is not critical, since with the DBS-22 it will have slightly different angles dependent on the drill size.
The tertiary relief according to Chernich is 45°. Akin to the seconary facet, it has to be carefully ground up to the tip.
[/img]
(Source: http://modelenginenews.org/meng/quorn/images/q6f_2.jpg)

Now on the DBS-22 you change from grinding the primary facet to the secondary by advancing the pin vise assembly one notch, after tilting the whole jig. The resulting relief angle remains to be determined.

Logic tells that repeating this step again by advancing the vise even further will produce a third facet – and this works. I encourage you to try this, but be careful and hold the vise firmly, it tends to get caught by the wheel. Let us know about your results, folks.

I recommend reading the pages on Gadgetbuilder´s drilling adventures linked above, particularly the ZIP file containing the sharpener plans., which is full of information on SPA´s, facets and splits.

[This information is intentionally removed.]

This information is intentionally removed.

All information I ever give is free. I have nothing to sell.
In fact, to be even confused with that, is shocking and almost affronting.

FYI.
This is a very easy jig that lets me precisely set a certain angle by adjusting the distance from the top of the USB bar to the wheel (hereabouts known as "T-USB" - hence the name), according to the output of any of the simple, but most potent calculators provided here.

It can be realized easily without specialized tools, although a 3D-printer is pure luxury.

You could however make the same thing using a piece of hard wood or plastic or similar, with little more effort.

The idea is based on Perra´s T-Cube, and indeed this unit can be put to good use together with the described jig.

I found that the T-Cube probably excels at using a digital inclination measuring device, and while it may have several other uses (probably not discovered yet), it is not optimal for setting T-USB. If you use it like depicted by resting the bracket on the back side against the USB as shown in pic7, then a (possibly small) error is introduced by measuring the distance at the side of the USB (introducing an offset of 6mm from the USB´s centerline) down to the stone´s perimeter (T-USB is specified as the top of the USB to the stone measured through the USB´s center). Apart from this, one hand is blocked by having to hold onto the jig. The next question is, where does the ruler touch the stone.

So I realized that the ruler should really be 90° rotated and start with "0" flush with the USB´s top down.

I borrowed the mounting of the ruler from Perra´s T-Cube; a slot and a screw. Differently however, the ruler is not intended to ever move in there. This is just a convenient receptacle. The ruler has its last > 12mm sawn off, so that it fits into the fixture. Its length is designed in a way that the ruler, inserted to 5,0 cm, displays the exact distance from top of USB. There is no magic to that number, it could be made shorter, but I found T-USB numbers below 7cm useless.
I chopped the ruler off at 15cm, which promises a great span of projection distance vs. wheel diameter vs. angles.

The earlier printed T-Cube can be made to reside on top of the wheel to the side loosely, so that it rides up and down with gravity when changing the USB´s height, giving the exact reading on its edge.

Thanks to a snug fit of the 12mm bore the jig stays put in any position. Should this joint eventually become loose by frequent usage, a screw could be incorporated like the one that is there.

The ruler of course has to point perfectly towards the center of the wheel, and once you are close to the final destination, this should be re-checked. You could alternatively (as already adressed somewhere) use a rubber band around the wheel hub towards the ruler to center it automatically.

The reading you make on the moving part´s edge is then always guaranteed to refer to the wheel´s apex.

My friend is an expert to 3D printing (you would think this were a sunday afternoon walk for him, watching him). He says even a M8 nut is lousy to print on a 3D printer and of doubtful longevity, so he inserts a slot for a metal M8 nut as depicted in the detail picture. Brilliant.

Hope this is of use for somebody.
-Helmut

I better start a new thread or nobody will see this.

cbwx34 recently wrote to me over a different subject quoted in the following book:

(...)"Razor Edge Book of Sharpening" (which you can now get for free HERE)(...)

John Juranich writes in this book on p.56 that they use two "hones" as they call them, a "fast cutting" abrasive which he calls "fine" in the order of #100 and a "finishing" abrasive in the order of #400 to #600.

Now sharpening with two stones is basically coincident with today´s common agreements, but in the lights of today´s ever higher grit stones into the #10.000´s I wonder what grit gauging standard he is referring to; because #100 appears a pretty rough brick and #600 not very fine.

The reason I ask is because it interests me what he has to say on what he calls the "relief" (tapering the knife behind the edge, as discussed here). He does the relief with the coarse stone without further refinement, and only does the edge with the fine stone.
[he also does not mention about removing the pesky burr...]

I would guess (from the optics) that the book was printed in the 70ies. What standard may he refer to?
I doubt that back then Japanese waterstone sharpening was en vogue the way it is today.

Maybe somebody knows.
Thanks
-Helmut

(Don´t know which forum this fits. Move if necessary.)

I always was annoyed that Tormek does not sell a 200mm stone equvalent to their Silicon Blackstone.

I found a german guy who sells such a thing:  http://msc-handel.com/#produkte
It is a SiC wheel, grit F320 (=J600). He also has a stone called "Edelkorund weiss" (probably "white fused corundum" or "white fused alumina").
Note: Tormek gauges their grinding wheels according to JIS (I was told by a distributor).
This is a custom job done on special order for him by a well known local maker for abrasives (BSW). The wheel has the same cut-out as is customary for Tormek wheels.
Unfortunately the site is done quite simple and you probably would never find it.

You find him on ebay too.
https://www.ebay-kleinanzeigen.de/s-anzeige/schleifscheibe-siliciumkarbit-f-tormek-t3-t4-200-hartes-mat-/1908645684-84-7639

Use deepl.com to translate it to English if needed.

This stone would need to be treated akin to the SB. Vadim made a nice video about trueing and grading the SB. The dressing stone would not work because it is made from the same material, however the diamond works of course. (I must get some diamond plates as he suggested...)

I sharpened some drills with it and this was a real joy. The SG did not really cope with big HSS drills. BTW I ran into the same problem with the drill jig as everyone, and I landed with the same solution intuitively...

The stone is made very precise, it fits the 12 axle much tighter than the SG that was on the T3, which has play. I have to open and fasten the SG several times to stop it from wobbling side-ways every time I change stones - not on the SiC wheel! The T3´s flanges (if you can speak of such...) are really lousy and don´t guide the stone wheel enough. A fast running wheel with such lousy side support would blow into your face upon turning on the first time.

Have fun
-Helmut

Greetings,

this is my second post...
I just recently stumbled over Vadim´s Work and bought the deburring booklet.
I wrote to him, not knowing that he has left this planet... (the web site says nothing about that...)

So you guys may know the answer.

Hereabouts (Austria/Germany) there is a guy well known, Friedrich Kollenrott, who is kind of gold standard on sharpening. He and some other guys recommend "thinning" the blade region close to the edge, up to about 1/3 of the blade height or thereabouts, particularly after it has been re-sharpened times and times, which lets the secondary facet become larger and larger due to the edge gradially approaching the back of the knife.

He wrote a document which has become a kind of "sharpeners bible":
https://www.feinewerkzeuge.de/pdf/Schaerfen_von_Messern_211207.pdf
Pictures #4 and #5 show what I mean.
The supporters of that method say the knife cuts easier this way. (This is all about kitchen knives). But this might be another myth.

I read nothing about this here, at least I did not recognize it.
in this thread https://forum.tormek.com/index.php/topic,3419.0.html a "microbevel" is mentioned and the pictures here https://forum.tormek.com/index.php/topic,3437.0.html suggest that it would be a compound bevel. I am not quite sure, if this is the same thing.

I have tried grinding that flat with the jigs, but had the stone collide with the jig.
I was uncertain as what angle we are speaking about.
Apart from that, this would produce a hollow secondary bevel (is this the right term for it?), which may be counterproductive.

I have tried several ways of doing this free style on the tormek, but the result left a lot to be desired...

The only way I can imagine is doing it on the side of the stone, much like Vadim tried it on a single bevel knife. I have bought the MB-100 to give that a shot.

I have a T-3 and use stones only. I thought up a method for trueing the side.

So I would appreciate to hear your thoughts on this subject, folks. I may toss the subject in one second if you say this does not pay. It certainly causes head ache.

Thanks,
-Helmut

(This subject probably affects only readers in Austria and Germany, but this is the place to post it anyway.)

Just recently I bought a T3 model and sharpened a few chisels to perfection.
Sobering, when I put my Stanley hand planer´s blade on the machine, which is obviously HSS.
After half an hour I gave up, when only half of the blade was done.

I looked in the web for rougher stones, but you only seem to get finer stones, at least for the T3.
A diamond wheel might be the solution, but this is another investment. But a cheap workaround is at hand.

I happened to have a wet/dry grinder machine that is ubiquitous in home-department shops in Austria and Germany similar to the one shown here:
http://www.walter-service.at/index.php?page=product&info=1669

I suspect this is a chinese machine which is sold by a couple of tool traders under different names.

It consists of two grinding stones, one high speed dry and one low speed wet grind both mounted at a 90 degree angle.  The machine comes at a price of about 50 Euros. Maybe the stone can be obtained as a spare on its own..

It turns out that they use the same dimension grind stone (200 mm * 40mm) as the T3 although with a different bore. However, their machine uses the same axle and they use an adaptor. The stone appears much rougher, I guess a 120 grit from the information on the website. The wet stone they sell as compatible article has 80 grit and a ridiculously low price.
I used their adaptor and lo and behold, the grindstone fits perfectly albeit with a small wobble which does not hurt.

It ground the planer blade into shape in one minute flat. A little touch-up with the SG stone in 1000 grit mode and that was it - razor sharp HSS planer blade with a perfect angle.

A different solution would be to use their bench grinder mounting set BGM-100 with some makeshift holder on the cheap machine, but the prior solution is more elegant and maintains the correct angle as long as the stones have the same diameter.

I consider this workaround not financially detrimental to the Tormek series of articles, because such a stone is simply not available. In the contrary, this should encourage you to get a T3 folks!

-helmut