sharpening setup – slow speed grinder with CBN or diamond?
hi all! I’m looking for some advice on buying a sharpening setup. So far, I’ve been sharpening with diamond stones and a couple of water stones for finishing with decent results, but there are two problems: I think I got get better and more repeatable results with a machine, and regrinding a bevel on my PM-v11 plane blade even on my coarsest plate (atoma 140) is a huge pain.
Now, I’m in for a bonus at work and was looking to invest in a sharpening setup, but it’s been a difficult choice. Here is what I’ve been thinking:
– Tormek T4: expensive, but I hear good results. However, I feel I’d need at least the square edge jig and the truing tool, or a diamond wheel plus the square edge jig, both of which would make this a more expensive solution still. The biggest problem is though that it seems using this setup to re-grind a bevel would still be very slow – though it’s hard to find out how slow. The advantage is accuracy and the ability to flatten backs with this setup.
– a low speed grinder like the drechselmeister dml 200N (I live in Europe), with a CBN wheel for less maintenance and the tormek BGM 100 jig for accuracy. This looks like the best of both worlds when it comes to accuracy, speed and repeatability. Another advantage would be versability: I guess I could mount wire wheels etc for rust removal and other apllications. However, this setup would not be able to flatten backs. Would it be possible to use a tormek diamond wheel on a low speed grinder like this?
As you see, a lot of doubts and questions – any insights here would be appreciated!
Thanks,
Daan
Replies
The "go-to" setup for many turners is an 8" slow speed grinder and CBN wheels. The CBN wheels wear so slowly it's almost imperceptible. They'll last many years and they do not change diameter like friable wheels. This allows for repeatable results with grinding and sharpening jigs.
I also agree with eweber. I suggest going to the Woodturners wonder web site and taking a look at their setup. I switched over 2 years ago and have not regretted the switch to CBN wheels. I also bought their sharpening system. It is fool proof and very repeatable every time. https://woodturnerswonders.com/
If you don’t want to invest is a grinder and you only sharpen plane irons, then check out the Lee Nielsen site for his sharpening guide.
https://www.lie-nielsen.com/
By the time you have bought a slow speed grinder and the CBN wheels, you are getting into Tormek price territory.
Also you need to be aware that CBN is for HSS steel only - it does clog if you try to grind softer steels on it, and most tool steels are softer than HSS, though I have never tried PMV11.
I use the grinder and CBN for most turning as it's really fast and easy. great for gouges of all kinds.
For other tools, I use stones and though I have invested in the Tormek it's still in its box so can't report any personal experiences.
I had a Tormek long ago, and sold it. It's excruciatingly slow. When I grind it should only take a few seconds.
While CBN wheels have been around a long time, I was probably the first to write about them for flat woodworkers and develop a grinding system. This seems like many years ago now, but was only in 2015.
The full description of the system I came up with is here:
http://www.inthewoodshop.com/WoodworkTechniques/UltimateGrindingSharpeningSetUp.html
Seven years late, after much use, the system remains the same. I am very happy with it.
Note: the half-speed bench grinder is really only needed for plane blades and bench chisels. If you are a turner, where HSS lathe chisels are the norm, then a high speed bench grinder would possibly be better (as the little extra heat does not make a difference this this instance).
Lastly, the wheel that I use 99% of the time is 180 grit. I have a 80 grit as well, but this is only needed for refurbishing blades. If you are a turner, you will want higher grits, possibly 180/240 for shaping and 360/600 for sharpening.
Regards from Perth
Derek
I don't know how the warnings against grinding chisels and plane blades on CBN got started. But I have zero problems using them. I wouldn't try unhardened metals, but I have no need to. I'm glad to see you had the same experience.
Ditto,
I don't remember how long ago i got my first CBN wheel, it has to be over ten years now. You can grind most typical items you would find in a woodworking shop, except aluminum which can clog it up.
For turning, a slow speed grinder is usually preferred With a high speed grinder, it is too easy to over grind with a CBN wheel and too easy to overheat with a friable wheel.
It was actually this article that inspired the second option I listed. And yes, I'd be working on plane irons, chisels, spokeshave blades etc, no turning tools. The option I'm looking at is this with the tormek BGM 100 (https://dehoutdraaierij.nl/en/shop/grinding/machine/). The owner of the shop recommended a higher grit CBN wheel as the other wheel is ideal for re-grinding. I'm thinking of adding a felt wheel for polishing, and that would cover all needs from re-grinding to final honing and polishing. What do you think of this setup? The only problem for me would be that the CBN wheels he provides don't have grit on the sides for flattening backs, and I don't know where to buy wheels like that in Europe.
Thanks for your help!
Daan
I would stay away from felt wheels and power buffing of edge tools. You'll round over edges quickly. It makes pretty and shiny surfaces, but the angles on your edges will be much too high.
I have been using the 360 grit on my 8 inches high speed grinder for many years now mainly to sharpen bowl gouges, some are carbon steel some are the more exotic materials. Once set-up with the wolverine guides, it’s a matter of seconds to get a fresh edge. The wheel on the opposite arbor is a blue Norton 80 grit that used to be the standard to sharpen turning tools, it requires constant trueing and cleaning and one day, a CBN will replace it too.
I too am just getting set up with a new grinder and some better quality wheels. Time to retire the old Frankenstein garage sale set up! any thoughts on wheel diameter? I was going to go 8", but I see Norton also makes 6" wheels. Is the deeper hollow grind worthy, or should I go with the 8"?
Thank you in advance.
I'd suggest spending a few $ on Schwarz's booklet 'Sharpen This'. Might change your mind about what you 'need' to get sharp and back to work.
Was just what I was going to suggest as well. He uses his grandfather's old high speed bench grinder. I like any bench grinder as well. If I were going to but something today, I would be inclined to get Rikon's Tormek knockoff. It's on sale at Rockler for like $170 or$180 and I'd stick with whatever grinding stone that comes with it. From my perspective, any electron powered grinder would be helpful for when I need to do something significant. As for day to day sharpening, I would reccomend a sharpening jig if you think the freehand you might be doing isn't giving satisfactory results.
I use CBN wheels on a slow speed Toycen grinder to hollow grind the primary bevel on my chisel and plane irons, and then hone the cutting edges using a Lie-Nielsen honing guide and Shapton stones. While this setup is expensive, (cheaper variations are available) it works great for putting a sharp edge on all my tools. I have a 4 part sharpening video series on YouTube (Swenson Woodshop) that details my system and technique.
It sounds like you have what you need (water stones) to hone a secondary bevel. So, from what I'm gathering you're looking for a way to grind a primary bevel.
Pick up a ubiquitous (read: cheap) 6" grinder, put on a Norton high friable wheel and tool rest and get to work. I think there's a blog post from Megan Fitzpatrick about this here.
For flattening the backs, get some sandpaper and the flattest marble threshold you can find at the home center.
All in... $100? Maybe $150.
Don't over think this. Sharpen your tools and get back to work. Sharpening is not a sport.
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