CBN Wheel Grit for 'Flat' Woodworkers

[Hasin Haroon]

Hi All

I have been wishing to switch hollow grinding my chisels and blades for some time now. Now that Lee Valley carries CBN wheels, they are readily accessible and I am ready to make the switch. I will be using the grinder primarily to reshape bevels (a lot of my vintage tools have been sharpened at way too steep a bevel), and remove nicks and chips from blades before sharpening on my water stones. I will be using a 1 hp slow speed grinder (1720 RPM). While I do some turning, I am mostly a regular woodworker, and will use the wheels accordingly. I use a mix of O1, A2 and PMV 11.

My options are 80 grit or 180 grit, flat wheels. Is the 80 too aggressive (leave scratches too deep that will take a while to hone out) or is the 180 too slow? I'm hoping those of you who use these wheels will be able to suggest the best one for my purposes. I've looked at past posts on CBN wheels, and while a lot of the merits and issues have been discussed, the relative utility of the different grits hasn't been touched on much.

Thanks!

[Malcolm Schweizer]

If you are only going to use it to grind hollows, and you have other methods of establishing the edge, I'd go with the 80 grit. If your sharpening methods are limited, the 180 will take a little longer, but leave a finer edge which means less work for the next steps. I personally have a Tormek and I'm thinking about getting a CBN or diamond wheel for it, but the next steps would be the Tormek wheel and then water or oil stones to finish. I'm probably going to go for a coarser grit. I wish Lee Valley had these in 10" so they match the profile of the Tormek.

[Chet R Parks]

Malcolm, You can get the Tormek style (10 x 2) CBN at Woodturners Wonders for $180 plus shipping. Sorry if you already new this.
Chet

[Todd Stock]

80 grit 8" diameter by 1" wide radiused wheel works much like a traditionally dressed SG grinding wheel, except cooler and - of course - no dressing dust. Tools for Working Wood has them. The Veritas supports work well for hand-held work, but fixed shop-made supports are easy to do as well. Bevel established with a coarse diamond stone with a few swipes and finished with an 8000 water stone goes quickly. With more time spent, an India for the bevel and natural oilstones to polish gets the same edge.

Re: Tormek...finally sold mine after 15 years for more than I paid for it...too slow to fit in the work flow. Running side by side with a low speed grinder & CBN wheel combo, the Tormek sat unused by students and the other luthiers that visit the shop. With the new diamond or the 10" CBN, I suspect the Tormek would speed up a bit, but doubt it's anything close to what I see with the low speed grinder and 80 grit wheel.

[Hasin Haroon]

Thanks Malcolm and Todd. Looks like I have two votes for the 80 grit CBN Wheel. I have ceramic waterstones in 1000, 4000 and 8000 grit. From what I read, the 180 grit is very aggressive, so I was worried the scratches from the 80 grit would be too deep and take too long to hone out (and a big reason to go CBN for me is the speed).

[Frederick Skelly]

Hasin, I use a 120 grit CBN. I like it a lot. It cuts well without leaving deep scratches. I suspect that 180 would be too fine a grit for just reshaping my bevels.

Fred

[Edit: Thanks Vincent. Your experience with the 180 is useful information.]

[Vincent Tai]

I have a 180 and 220 wheel. Both are very fast and the 220 leaves a nice finish. Both are faster than a 80 grit white wheel. The 80 grit CBN wheel must be really really fast. I'm thinking of getting an 80 grit or even 60 grit but that'll be for heavy shaping for me. 180 leaves a nice surface while being pretty quick at resetting bevels or grinding past nicks. Only reason I'm looking for anything coarser is because I have to grind a brand new bevel on chisels or irons I make so thats a decent chunk of steel to grind away. Still done easily with a 180 but it gets beyond 10-15 min on wider irons or when doing shaping. Below's a chisel that I made from some O1 scrap and shaped on a bench grinder with a 180 CBN wheel. Took about 30-40 min I think; and there was a decent amount steel to grind away. If you do get the 80 grit LV CBN wheel let us know how you like it; I really like Ken's CBN wheel from Woodturner's Wonder's but being able to get wheels with a run to LV is a major plus. I don't think you'll have trouble with getting a nice edge from an 80 grit wheel because its very easy to grind very accurately with CBN wheels; even if you have to take a few extra passes on your first stone you'll still have pretty tiny bevel landings. I remember Derek's writeup on CBN wheels saying that from what he could tell the 180 grit was nearly as fast as the 80 and provided a smoother finish. If theres a pre-existing bevel of sorts it should be rather fast to establish the new hollow ground bevel with a 180 wheel. I recently had a 1" PMV-11 chisel slam (with full force of a mallet) into a surface it wasn't suppose to. Took about 25-30 secs for 99% of the damage to be ground away. Another half minute and I was good to go sharpen. It's when grinding a bevel from scratch I long for the extra muscle of coarser wheels.
383067383068383069383070

.

[brian zawatsky]

I have CBN wheels in 180 grit and 600 grit which came from Ken at Woodturners Wonders. I bought them specifically for grinding bowl and spindle gouges (I was bit by the bowl turning bug a few years ago). 180 is plenty fast enough for me when re-establishing a hollow grind on plane irons. CBN cuts very fast, I think you have a high potential for wasting a lot of steel with an 80 grit wheel. Just my .02

[Todd Stock]

Coarser wheels are generally going to cut faster and cooler than finer grit wheels, but leave a rougher finish. For turners, that matters, because some tools are used directly off the grinding wheel, so going to a finer wheel makes sense. For flat blades like chisels and plane blades, the wheel forms the ground primary bevel, and the honed secondary bevel is formed with a much finer grit stone (e.g., my 325 DuoSharp diamond stone)...so the concern with having to work out deep, coarse scratches from an 80 grit wheel is not something we have to worry about because we never hone the primary bevel. One of the reasons why I prefer the CBN 80 grit/1725 rpm grinder is the speed that something like a 2" framing chisel can be reground without much in the way of concern with overheating, and things move along a lot faster than with conventional wheels, but slow enough to control the tool.

I've also not found that over-grinding is a valid concern with flat work...grinding stops once the honed bevel is removed, and the tool goes a long time between grindings because on most tools...I'll run the honed bevel out to 1/2 the ground bevel's width before heading back to the wheel.

[Patrick Chase]

A few thoughts:

When we dry-grind woodworking tools on conventional wheels we're limited by heat, not cutting rate. We spend so much time pausing, dipping, using ultra-light pressure, or otherwise avoiding heating that we're not working anywhere near the limits of any of our wheels. Our choice of grit for such wheels is therefore largely a matter of which wheel will heat the tool least while getting the job done.

With conventional wheels the dominant heat contribution is from friction, and that's basically the same per wheel revolution regardless of grit. In other words, 10 revolutions of an 80# AlOx wheel heats the tool basically the same amount as 10 revolutions of a 180# AlOx wheel. The 80# wheel can finish any given job in less revolutions because it removes more material per turn, and that means that the 80# wheel will dissipate less total heat into the tool to get any given job done. This is why we typically use coarse-grit conventional wheels.

CBN wheels are very different, in that the sharp diamond points cut so efficiently that friction is no longer the dominant source of heating. I've seen one study showing ~1/5th of the frictional heating for CBN vs AlOx at any given speed/grit/pressure setting. This in turn means that you can work efficiently (without undue time spent paused/dipping/etc) with a higher-grit wheel when using CBN than you can with Alumina.

To put this in concrete terms, I mostly use 80# AlOx wheels ("white" or "blue"/3X), but I use 180# or even 350# with CBN. I have an 80# CBN wheel but seldom use it. The higher-grit wheels are more than fast enough, barely heat my tools, and provide a better finish and more gradual/controlled material removal.

[Derek Cohen]

I am coming in a little late here ... away in New Zealand at present, trampling around the forests.

I have 80 and 180 grit wheels. THe 180 grit is used 90 % of the time.

The importance of a smoother grit lies in the way the hollow is finished. I grind to the very edge of the blade. The 180 grit leaves fewer serrations than the 80 grit. The 80 grit is faster to grind, but for general use, the 180 grit is plenty fast. The 80 grit is reserved for when grinding a lot of metal.

The smoother edge off the 180 means that it is possible to go straight to a Medium Spyderco (or 6000 Sigma) before finishing on a UF Spyderco. This creates a micro bevel that will stay micro a long time. Equals faster sharpening.

220 grit is too fine for flat grinding. It will create more noticable heat, which is not a good thing. The 180 grit, with light pressure, remains lukewarm.

Regards from Auckland

Derek

[Vincent Tai]

I am coming in a little late here ... away in New Zealand at present, trampling around the forests.

I have 80 and 180 grit wheels. THe 180 grit is used 90 % of the time.

The importance of a smoother grit lies in the way the hollow is finished. I grind to the very edge of the blade. The 180 grit leaves fewer serrations than the 80 grit. The 80 grit is faster to grind, but for general use, the 180 grit is plenty fast. The 80 grit is reserved for when grinding a lot of metal.

The smoother edge off the 180 means that it is possible to go straight to a Medium Spyderco (or 6000 Sigma) before finishing on a UF Spyderco. This creates a micro bevel that will stay micro a long time. Equals faster sharpening.

220 grit is too fine for flat grinding. It will create more noticable heat, which is not a good thing. The 180 grit, with light pressure, remains lukewarm.

Regards from Auckland

Derek

Interesting that you found 220 too fine. I used my 220 wheel exclusively for a few months when I first got my wheels because I only have one tool rest. I found it very acceptable for flat woodworking tools and even ground some bevels from scratch on 1/8” thick small plane irons. For grinding away the inevitably largened micro bevels I found that no dipping in water was needed, lukewarm like 180 wheel use. For grinding new bevels I dipped once or twice. I have a habit of keeping my fingers dangerously close to the edge and wheel, and dip well before the any uncomfortable heat levels occur. I have a habit of dipping even at that lukewarm level that tools stay at for a few minutes on a 180 CBN wheel. Saunas would laugh at the temps I dip at. When I started getting my head around how cool CBN wheels run I started moving my fingers further away for most of the grinding. I spent a lot of time in high school a few years ago standing at a bench grinder. On one particular day I logged a total of nearly three hours. There were many forgotten and unused or abused hand tools in the shop (the ones that were used daily were also abused) and my teacher was trusting enough to let me have a go at them. There was literally rows of unused Stanley No5s in a storage room rescued from their destination to the grave. Other high schools that were putting an end to their shop programs had handtools lined up for the gallows and a few sensible teachers liberated them and had them stored for years and years in my HS. I was careful from the very first iron I tried on, and never did any water at edge sizzling nonsense. I dipped so frequently the iron would be room temp and I’d dip it. Every time I inspected progress I dipped. It’s such a habit I don’t find a bothersome when I have to dip 2-4 times grinding a shallower bevel on a tool with a steeper established bevel when using the 220 CBN wheel. The 180 is certainly a better wheel for heavier work and versatility but I’m glad I have a 220 wheel. I suppose I may be used to dipping so often that once or twice with a 220 CBN wheel was/is heavenly to me. Just need to get another tool rest so I can use both easily.

Cheers,
Vincent

[John K Jordan]

Hasin,

My experience:

I have four CBN wheels mounted to sharpen lathe tools. I have also used them on chisels and other non-lathe tools. I have 80 grit, 220, and 600 grit on 8" bench grinders and a 1200 grit on a Tormek (and a 600 grit Tormek wheel on the shelf). I had a 320 grit wheel on a bench grinder but I sold it and got the 220 since it was close to the 600 grit. All of my wheels are flat across the face with square "corners" and a 1" flat down the sides. I tried one with the radiused edges but didn't like it.

383090

I rarely use the 80 grit and only for major resharpening of fairly large and thick HSS tools, but not for sharpening. For example, I shaped these negative rake scrapers from 10v Thompson stock, 3/4" and 1" wide - they started out as square end tools so I hand to remove a LOT of metal.

383089

For every thing but major reshaping (for all sharpening) I use the finer wheels. I can easily do less aggressive shaping on the 220 grit wheel and even the 600 grit. Both leave a better surface than the 80, of course. I'm surprised at how quickly even the 600 grit wheel will remove metal for minor bevel changes for even relatively wide bevels on skew chisels. I use the 1200 grit wheel on the Tormek for my spindle gouges and a few other tools - it turns so slowly it removes very little metal but still sharpens quickly and I love the edge it gives for turning tools. If I rated the wheels I have by the amount of use they would be in this order: 600, 1200, 80, 220. Although I think the 220 grit is a good multi-use wheel I rarely use it since the 600 does such a good job.

However, if I had just one wheel I would get a 220 or maybe even a 320, aggressive enough for some shaping and fine enough for most sharpening.

Do you know anyone nearby who has a CBN wheel you can try? I've had several people come to my shop to try mine. A lot of woodturners use them so one possibility of finding someone is to contact a woodturning club. It seems that woodturners, like other woodworkers, love to share. :)

Another possibility is to call Ken Rizza at Woodturners Wonders and ask him. He may have feedback from customers with similar needs, may know someone near you, or may even be able to work a deal to let you "audition" a wheel, perhaps a used one - I don't know if he would do this but it doesn't hurt to ask.

Be advised that a new CBN wheel will cut much more aggressively than one that is "broken in". Apparently the electro depositing method leaves random sharp bits of CBN gains proud of the surface. After some hours of use the corners of these must be knocked off and the wheel settles down to it's long term state.

Reed Grey (Robo Hippy) has an article on CBN wheels you might find interesting, from the perspective of a woodturner who mostly makes bowls: http://www.robohippy.net/featured-article/

JKJ

[Rob Lee]

Hi Hasin -

I would recommend the 180 grit - it's not really that much slower, and will yield a better finish for moving on to final honing.

While turners have been early adapters of CBN wheels - they have been slower to penetrate the "flat" world. Derek was kind enough to run me through his set-up when I was in Australia, and he's really worked through his workflow with CBN. Not only has he been using them for years, he's worked through various grits and styles as well.

I'd be happy to arrange a session at the Edmonton store, where you could bring in some blades or chisels, and give each wheel a try. Just mail me directly at rlee@leevalley.com to set it up. In any event - we are always happy to take back products that don't meet your expectation.

Cheers -

Rob

[Hasin Haroon]

Vincent, I am also quite accustomed to dunking my tools more often than is necessary to prevent heat build up when grinding (unless I've spent a few hours at the grinder, those last chisels may lose their temper). Also, that's a very nice looking chisel. You should share photos of the other tools you've made.

[Hasin Haroon]

Thanks Derek, Patrick.

Being able to grind accurately all the way to the edge would save some time and wear at the waterstones, so that's a big plus for the 180 in my mind.

I read your write up on CBN wheels as my first point of research Derek, I hope you keep posting (and sharing) your articles regularly.

[Hasin Haroon]

That's very helpful John. I've tried out a 180 grit wheel on a friend's grinder, but only to touch up gouges. It did seem to cut very fast, but that was also the first CBN wheel I was exposed to. I did read Reed Grey's article but it seemed to focus more on HSS lathe tools.

[Hasin Haroon]

Thanks for the suggestion Rob, 180 does seem like the best bet. I was so glad to see LV carrying the CBN wheels. It's great to have them available locally.

Also, thanks for the kind offer, but it seems like too much trouble to put your staff through. I don't doubt I'll be pleased with whichever wheel I choose, or that LV CS will make things right if there's any issues (Also, a lot of the Edmonton staff recognize my face by now, I really need to stop frequenting so often).

[David Silverson]

Is there any chance LV will carry a 10" CBN wheel for use on the Tormek? Or, might LV carry the new diamond stone from Tormek?

[brian zawatsky]

Hi Hasin -

I would recommend the 180 grit - it's not really that much slower, and will yield a better finish for moving on to final honing.

While turners have been early adapters of CBN wheels - they have been slower to penetrate the "flat" world. Derek was kind enough to run me through his set-up when I was in Australia, and he's really worked through his workflow with CBN. Not only has he been using them for years, he's worked through various grits and styles as well.

I'd be happy to arrange a session at the Edmonton store, where you could bring in some blades or chisels, and give each wheel a try. Just mail me directly at rlee@leevalley.com to set it up. In any event - we are always happy to take back products that don't meet your expectation.

Cheers -

Rob

Now that's customer service!!

[Sean Nagle]

On the Tools for Working Wood site, Joel is offering only very coarse 60# and 80# CBN wheels. However, his wheels are crowned compared to the flat Lee Valley CBN wheels. Joel has a blog on grinding and recommends dressing a wheel with a crown. I have always dressed my wheels flat. What is the general consensus for crowned or flat wheels?

[Patrick Chase]

On the Tools for Working Wood site, Joel is offering only very coarse 60# and 80# CBN wheels. However, his wheels are crowned compared to the flat Lee Valley CBN wheels. Joel has a blog on grinding and recommends dressing a wheel with a crown. I have always dressed my wheels flat. What is the general consensus for crowned or flat wheels?

My impression of Joel's offerings is that he hasn't really thought through the differences between conventional and CBN, and so he's basically offering CBN versions of what he's always used/recommended in conventional wheels.

I've already noted why CBN favors higher grits, and there's similar logic at work with crowning. The challenge with flat wheels is that it's difficult to apply perfectly uniform pressure all the way across the face, and so one corner ends up with more pressure than the other, leading to localized heating. If you tilt the workpiece such that only the corner is cutting then the problem becomes particularly acute. Crowning avoids that by relieving the wheel edges such that only a broad (not pointy) section in the center cuts. The downside to crowning is that it can be a bit wasteful of abrasive, since the center takes most of the cutting load.

CBN wheels run cool enough that it's simply not necessary to crown the wheel IMO. Even if one corner or the other gets more pressure, it won't create enough local heating to be a problem. If you're used to working with crowned wheels you might subjectively prefer to work with a crowned CBN, but other than that I don't think it's worthwhile. If corner heating were an issue then one obvious "intermediate" solution would be a rounded-corner CBN wheel.

EDIT: I don't crown my conventional wheels either, FWIW. I grind freehand off of a tool rest, but am very careful about how I present the tool to the wheel. In particular I always hold the tool such that I see sparks all the way across during grinding, even when adjusting skew (in the latter case I might apply more pressure on one side than the other, but always with the whole wheel cutting).

[Derek Cohen]

I would just echo all you have written, Patrick. Well covered.

Regards from Auckland

Derek

[Tom M King]

If I ever set up a CBN wheel for sharpening mower blades, I'll get an 80 grit, or so. For several years, a 180 has done everything I need to do with irons, and chisels, and speed is very important to me. When going from the 180 to stones, it's just like going from one stone to the next, with no noticeable extra time required.

I'll only be going back to wet grinding, when the Tormek diamond wheels come out, because I can't dry grind in the houses I work on, even with CBN wheels. While you don't have all the mess from friable wheels, metal chips still accumulate, and some get thrown where you don't want them.

[Patrick Chase]

Thanks for the suggestion Rob, 180 does seem like the best bet. I was so glad to see LV carrying the CBN wheels. It's great to have them available locally.

On a related note, LV have also started carrying the 1 hp Rikon grinder (http://www.leevalley.com/us/Wood/page.aspx?p=76585&cat=51&ap=1), which is a great choice for CBN wheels IMO. It has beefy bearings and more than enough power to handle solid steel CBN wheels (though I use the lightweight Aluminum ones from WoodTurners Wonders now). One benefit they don't mention is that the flanges are made out of solid discs rather than the usual sheet-metal stampings, and provide a lot of registration to both the arbor and the wheel face. Conventional wheels run much truer on my 1 hp Rikons than on my variable-speed Delta, for example.

[Todd Stock]

I don't think it's a heat build-up issue so much as whether the tool is jigged up or ground freehand (e.g., Tormek or the Veritas blade holder/rest system vs. tool rest setting only angle). For freehand grinding on planes and chisels, it's easier for me to move the tool into the wheel at the center of a crowned wheel, and move left and right to remove material. Any minor misalignment between the plane of rotation and the centerline of the blade is corrected after the tool is in contact.

For those jigging chisel or plane blades for grinding, there's little danger of feeding the blade into the wheel off-axis, so a flat wheel face makes more sense. We grind tools infrequently, as we use a ground and honed bevel on most tools. The job usually takes a couple dips in the coolant even with an 80 grit CBN wheel, so the rationale for crowning wheels - whether SG or CBN - remains valid (at least in this shop).

We did trial crowned and flat-faced wheels...after running them side-by-side for a few months, I passed the flat-faced wheel to my repair tech, who prefers to grind her tools using a jig (a repurposed spare Tormek bar and plane blade jig).

Given the reduced numbers of cycles from wheel face to coolant trough and back with CBN, an aversion to the time spent on jigs on flat grinding jobs might merit a relook, but once the skill set is established to do the job freehand, jigging up for flatwork seems a little cumbersome.

[Alan Schwabacher]

One possible advantage of a metal wheel with bonded grit is that it is safer for grinding on the flat side. For those of you with CBN wheels, do you use the side? It seems the wide flat on some wheels might make flattening of old plane iron or chisel backs very quick -- or it could be that they could be quickly damaged. Can anyone comment on this? It could affect which CBN wheel is most desirable.

[John K Jordan]

For those of you with CBN wheels, do you use the side? It seems the wide flat on some wheels might make flattening of old plane iron or chisel backs very quick -- or it could be that they could be quickly damaged. Can anyone comment on this? It could affect which CBN wheel is most desirable.

All mine have 1" of flat down the side. I do use it, mostly when grinding special lathe tools where I take advantage of the corner between the front and the side. I have flattened the back of some chisels but only on the 1200 grit wheel on the Tormek - the others turn too fast and I'm afraid I'd mess up the chisel. I do use the sides on the bench grinder to touch up screwdrivers and such. Note that if you grind too much non-hardened steel or nonferrous metal you can load up the CBN wheel. Reed Grey once described fixing a wheel that was loaded up with mild steel by grinding a heavy HSS scraper.

Someone mentioned sharpening mower blades - seems like that might be a problem if the blades are not hardened tool steel.

JKJ

[Devon Curtis]

Is there any chance LV will carry a 10" CBN wheel for use on the Tormek? Or, might LV carry the new diamond stone from Tormek?

According to my local Lee Valley, their CBN wheels will also fit the Tormek. Haven't tried it myself, though.

[Shane MacMillan]

Picked up the new 180 CBN wheel from Lee Valley to try out following Dereks Ultimate Sharpening guide. Need to wait till may to get the Tormek parts with the May $10 discounts.

383605

[Patrick Chase]

According to my local Lee Valley, their CBN wheels will also fit the Tormek. Haven't tried it myself, though.

The Tormek has an odd-sized arbor (12 mm). At the very least you would need a reducing bushing to use an ordinary CBN wheel on it.

[Devon Curtis]

The Tormek has an odd-sized arbor (12 mm). At the very least you would need a reducing bushing to use an ordinary CBN wheel on it.

I believe they mentioned a bushing being required. It may not be available yet. I'll ask the next time I'm there, it just got mentioned off hand and I may be remembering wrong.

Shane, what do you think of the King low speed grinder? I've been thinking of picking one up for my shop.

[Shane MacMillan]

Shane, what do you think of the King low speed grinder? I've been thinking of picking one up for my shop.

Its cheap but it works well. The motor is not balanced the best so it wobbles a bit starting up but when it picks up speed its fine. Its not the wheels either, it does it with out them installed. No noticeable runout on the shaft.

[Devon Curtis]

Its cheap but it works well. The motor is not balanced the best so it wobbles a bit starting up but when it picks up speed its fine. Its not the wheels either, it does it with out them installed. No noticeable runout on the shaft.

Good to know. I was a bit worried about the possibility of runout. Thanks!

[Dan Grano]

Hello everyone. Per the recommendations in this thread (and elsewhere) I am looking to get a 180 grit CBN wheel to hollow grind plane blades and chisels. I'm looking at the options from Woodturners Wonders and I was wondering if those of you who use CBN wheels for this purpose have found the 1" wide wheels to be sufficient, or if there are any benefits in considering a wider 1.5" wheel. The WW lineup has both options, with about a $60 difference in price. Thanks!

[ken hatch]

Hello everyone. Per the recommendations in this thread (and elsewhere) I am looking to get a 180 grit CBN wheel to hollow grind plane blades and chisels. I'm looking at the options from Woodturners Wonders and I was wondering if those of you who use CBN wheels for this purpose have found the 1" wide wheels to be sufficient, or if there are any benefits in considering a wider 1.5" wheel. The WW lineup has both options, with about a $60 difference in price. Thanks!

Dan,

One inch works fine. One option you might look into is a "crowned" CBN wheel from TFWW. While I haven't tried one, one of my complaints about CBN wheels is not being able to put a slight crown on the wheel for freehand grinding. BTW, I have both CBN and low grit stone wheels for the low speed grinder and diamond, CBN, and the standard stone plus Japanese water stone for the Tormek. I've gone back to using the standard stone and the Japanese water stone on the Tormek for all but repair grinding.

ken

[Dan Grano]

Thanks so much, Ken. And I appreciate the tip on the crowned wheels from TFWW. I'll definitely check those out.

[Phil Mueller]

Dan, I have the one inch and it works well. I like to able to put the entire chisel edge on the wheel at one time without moving it back and forth and 1” covers pretty much every chisel width I have. I thought about the 1.5”, but even for plane irons I’d need to move it back and forth, so wasn’t worth the extra $ for me.

By the way, I do prefer the 180 grit over the 80 grit for hollow grinding. Just less to finish the edge.

[Derek Cohen]

Dan,

One inch works fine. One option you might look into is a "crowned" CBN wheel from TFWW. While I haven't tried one, one of my complaints about CBN wheels is not being able to put a slight crown on the wheel for freehand grinding. BTW, I have both CBN and low grit stone wheels for the low speed grinder and diamond, CBN, and the standard stone plus Japanese water stone for the Tormek. I've gone back to using the standard stone and the Japanese water stone on the Tormek for all but repair grinding.

ken

Ken, you may wish to revisit the early posts in this thread for Patrick's comments about a crowned wheel, which I support. Short version: stick to the flat face.

Regards from Perth

Derek

[Aaron Rosenthal]

I’ve just begun to use my new Rikon 1/2 horse 8” grinder and an also brand new 180 grit CBN wheel.
I have a number of plane blades to straighten and also to refrind back to 25 deg. primary bevel. I’m using the Wolverine tool rest.
The 180 is fairly slow, and I had to scratch some parallel lines into the rest so I wouldn’t skew the blade unduly. Also, even though Rob Cosman touts the rest as a heat sink, it is easy to overheat the blade.
The other thing I wasn’t expecting was the relatively rough surface at the primary bevel as well as the undulating surface. I’m going to have to make a jig to keep the blade perpendicular to the wheel.

[David Silverson]

I have the Rikon 1 HP with the 80 and 180 wheels. I drew lines on the rest and that made it easy to freehand grind nice and square using the rest, I don't expect you'll need a jig. Love it and sold my Tormek.