Messages

How large is the delta between the T8 shaft OD and the wheel hole ID? Is it large enough (>0.4mm) so that one could simply 3D print a sleeve (e.g., using a 0.2mm nozzle) to slide over the shaft whenever mounting a wheel, or perhaps turn a thin sleeve on a lathe?

I would be wary of anything that might increase strain on the stone, as it seems to be rather fragile. I wouldn't want to initiate a crack in the stone when the stones expands ever so slightly because it is wet.

As to the wobble in the stone, tightening the nut when the label is upright has become second nature. I don't even think about it anymore, it really is not that much of a loss of time.

In that case, maybe it would be a good idea to just use a microscope, and give the knife back with a before/after emailed picture of the bevel ? There are cheap usb microscopes that will still make adequate pictures.

I use bench binoculars with the left eyepiece replaced by a CCD sensor, and get fairly good images in a matter of seconds.

I'm not 100% sure your intuition matches what actually happens at the edge.

What happens at the edge is a local phenomenon : Whether the edge is prone to rolling/folding or not depends on the material and the edge angle.
Even a .1mm high bevel is still orders of magnitude bigger than the small elementary deformations that happen when an edge rolls or not.
So changing bevel height will not modify the robustness of the edge. You can have a look at the excellent Science of Sharp blog to get precise measurements.

On the contrary, I can direct you to a bunch of traditional japanese knives who have like a 20+mm high bevel, but the edge will never roll.

As for whether a smaller bevel will make the knife wedge itself into the food, remember the primary bevel is more acute than the edge bevel. So if it indeed has a discernible effect, it is the other way around : the higher the bevel, the more you have to wedge into the food. I attached a drawing of the same blade sharpened at the same angle, but the right one has been ground to get a higher bevel. It gets intuitive which one will put more strain on the carrot ^^.

In my book, the lower the bevel the better, because you get lower sharpening time and amount of metal removed. So you push back the time when the knife needs to be thinned.

Hope this helps !

Nick.

I don't think there's an absolute answer to this question. It will mostly depend on what steel the blade is made of.

First of all, the bevel height is not an issue per se :

• The more obtuse the angle, the smaller the bevel is. So a 10dps bevel might look higher but will probably be weaker than a 15dps bevel with standard steels
• Many japanese knives (called sujihikis/sujis/lasers) come very sharp out of the box, with barely a visible bevel because the blade is so thin, and no robustness issues. But they are not made of the same steel as Walmart 3-for-20-bucks kitchen knives, and they will hold a 12 dps angle without an afterthought.

In your case, you're in a very different position as - IIUC - the blade is thin because of prior abuse on a bench grinder. I would consider it the same way I'd consider a knive with half-inch-deep knicks along the blade : damaged beyond repair.
Assuming you're willing to invest the time and effort required to reprofile the blade to where it might perform adequately, you will have removed so much steel that the knife will look awkward, with a bulky handle, a weird bolster, a stumpy blade and either scars from the bench grinder, or a much higher thickness behind the edge.

That being said : you've sharpened it to 15 dps, don't worry about bevel height, that's as good as it can get. If it holds the edge well enough, well done ! If not, then repurpose it as a paperweight.

These wheels cost around $70US, and one is enough.

In France, I couldn't find those aside from Amazon, priced at a modest EUR 200. The BDX line of wheels is more widely available and more reasonably priced. Does anyone know how they compare to the 3X ?

And if you have access to a 3D printer you might want to take a look at this :

https://www.printables.com/model/394577-m6-knob-randelschraube-m6-fur-zb-tormek/comments

ABS/ASA are ideal for this use, PETG will do, CF-GF are optional.

I agree with Ken, compare the price of a DF-200 and your Tormek Black. If they are similar and you have real estate to spare, by all means go for the Black, you might even get to use your T4 as a honing station.

If the T8 Black is significantly more expensive than the DF-200, it's up to you to value having a limited edition T8 (that most non-sharpening-nerds will be clueless about).

A file will indeed work well, as will the rounded out SG. The worst that can happen is that you'll round it out some more. And you don't need any of the precision that comes with the Tormek for this : most of this part of the blade has such a low velocity relative to the brush being cut that it won't matter anyway.

And it would be a shame to risk your diamond wheel for this.

[...] anyone's tried going straight to the fine side of the SP after using the diamond wheels [...]

SP as in SP-650, the stone grading tool If yes, what are you not regrading, again ?

John, sorry to hear about your wrist. I hope you get well soon.

Thanks for the document, it is very clear and informative. I'm waiting for your video !

I suppose that with (jedi-)master-level skills it could be doable. But it's probably a very bad idea.

Diamond wheels do not like pressure so if you use only the shoulder you'll have to be extra extra light, as all the force of the blade will be focused there. Avoiding damage will be very difficult, though if you have just a couple blades it might no be such an issue.

Conversely, you'll be applying all the grinding effect on just the part that touches the shoulder of the wheel. So you'll have a lot of action just there. Grinding evenly to maintain the shape will be a real challenge.

And as will all stones you can't use the usual means (jig/bar) that allow for controlled angle grinding, which will not help.


Now about your brush cutter, I can't help but wonder : Are you 100% positive it is a recurve blade ? It looks to me like a straight blade but ground only in the tip area. You shouldn't have too much trouble grinding those on the Tormek, even freehand.

There are also few stones left unturned : compared to a few years ago, many improvements have been made.

Tormek now sells a FVB, the KS-123 solves the issues of the infamous AngleMaster when  sharpening knives, the pros and cons of each machine are well documented...

As for usage tips, any new Tormek user willing to lookup rich's Handbook or to spend some time searching the forum will find a trove of things to try to find their best match.

I guess we just have to wait for a new innovation by Tormek or the next controversial post to rekindle the fire of posting...

[...]

Hello, and welcome to the forum. I couldn't help but notice that 100% of your 2 first posts were resurrecting years-old posts to promote a commercial website. Not sure it's a good way to build up trust.

I just checked on the website of a french Tormek reseller, the SJs are 30% off. Which is about as high arebate as I've ever seen on anything Tormek.

Any idea why this would be ? Just a sales boost or are the SJs about to be replaced/discontinued ?

Hello,

I think the safest bet is to email support@tormek.se . You might also want to register your machine on the website even if it's way past the warranty period.