CBN wheels

[SergeiDubovsky]

Hi team!

I just got a couple wheels from Woodturners. 600 and 1200 grit. And I have 200 grit in route. Well... It's not exactly what I expected.
Woosh! And 0.5mm of steel disappeared from 600 grit in like 3 passes. I guess, the wheel needs break-in and I need to learn lighter touch.
It's a first time I use diaminds/CBN wheel with Tormek. I remember the break-in from Wicked Edge.

I am bit worried about the 200 grit I ordered. I can't imagine what to feed it for the initial break-in. How long will it be that steel-hungry?

Thank you.

[RickKrung]

I wouldn't worry about it, just take it much easier than you might otherwise.  I'd start with a knife or edge that isn't of great concern to you. 

Are you planning on using the WTW CBN wheels in water?  I don't know if they have any that are meant for running in water.  I have one of their 10" 180 grit CBN wheels that is NOT meant for running in water and the warranty would be voided if it were to be run in water.  You take responsibility for the wheel if you do run in/them in water.  I have made that decision for myself/my use and do run it in water laced with the Tormek anti-corrosion fluid.  I make extra effort to dry it thoroughly after a sharpening session is over, not between changing wheels. 

Rick

[SergeiDubovsky]

I am leaning to the water direction. It will be cleaner and a bit cooler. They don't expressly say that warranty is voided in the water. However, the warrant statement does strategically enumerate things they cover. And the rust is not in the list. I guess, it's worth a try to see how fast and how bad it will rust. It won't get damaged beyond usable state right away.

I guess the rust concern is coming from enormous surface area of the diamond/cbn coated plate. That would hold on to some amount of water. On other hand, it will be evaporating from the equally large area. I will keep an eye on the rust.

PS: The water trough doesn't fit between the wheel and the case. It seems I need a shim of some sort to make it fit.

[Ken S]

Running a dry wheel on a Tormek defeats the main advantage of a Tormek, a water cooled DUSTFREE environment.
In my opinion, the warranty problem with some CBN wheels was caused by careless users who left their wheels soaking in their water troughs between sessions and then filing warranty claims. I have not read any forum posts about wheels damaged from using water with an anticorrosion solution. These also keep the wheels cleaner. Considering that a set of superabrasive wheels, diamond or CBN, can easily cost $1000 USD, i consider the modest cost of ACC inexpensive insurance for wheel care.

Ken

PS If the wheel does not fit well in the water trough, two probable causes are 1) missing the stone washer which creates space between the frame and the grinding wheel OR 2) an oversize grinding wheel. Measure the diameter of your grinding wheel. A new wheel should measure 250mm. Some wheels not made specifically for the Tormek measure 253mm and are a tight fit.

[RickKrung]

WTW may have updated their warranty warning since I bought my CBN wheels.  I don't recall the bit about drying completely after use or the cautionary statement about risks associated with using solvents with anti-corrosion properties.  I do dry completely after use, but I do use Tormek's anti-corrosion solution.  Point really is that I know that I assume the risks of doing so and have made the decision to do so. 

THIS WHEEL IS NOT MADE TO RUN IN WATER - DO NOT RUN IN WATER UNLESS YOU DRY IT COMPLETELY AFTER USE.  CORROSION WILL START ALMOST IMMEDIATELY IF NOT DRIED. PLEASE NOTE BUYER ASSUMES RISK IF SOLVENTS WITH ANTI-CORROSIVE PROPERTIES ARE USED WITH THIS WHEEL.

Rick

[SergeiDubovsky]

Speaking of rust: I sharpened a pair of scissors on 1200 grit CBN, and in several minutes it got covered in orange spots. My first thought was, "wow, that was quick". But, it seems the rust is coming from carbon steel from scissors.

Second part - the ancient wisdom of unclogging diamonds from WickedEdge: Ultrasonic cleaner. If it is any similar, ultrasonic would remove the embedded metal in seconds.

[Ken S]

CBN wheels are designed to sharpen high speed steel woodturning tools with high speed grinders. Please do not misunderstand me; they do this function very well. I do not mean to criticize CBN used in its primary function. CBN deflects much of the heat away from high speed steel tools much better than traditional grinding wheels and it cuts very quickly. However, sharpening high speed steel is not the same thing as sharpening high carbon or stainless steel tools and knives.

I did some testing of CBN wheels for the forum some years ago. (This was before Tormek introduced its diamond wheels.) I noticed several things of interest to Tormek sharpeners:

All of the videos I found by CBN vendors used higher speed dry grinders and woodturning tools. (Some also sell these grinders.) In fact, several of the presenters preferred full speed grinders. The two most common grits were 80 and 180, which work well for reshaping and resharpening hss turning tools quickly. One vendor, whose wheels all have one inch bores, sells nicely machined and reasonably priced steel reducing bushings. Although these work well dry, they quickly rust when used with water. This was not a problem when used with an anticorrosion solution.

The wheels were (and in some cases still are) oversized (253mm diameter). They are really designed to work dry, with no guards or water troughs.

Tormek ACC does more than prevent corrosion. It also helps to keep the wheel clean. In my opinion, trying to economize by not fully protecting one's investment in superabrasive wheels by skimping on anticorrosion solution is penny wise and pound foolish.

Ken

[3D Anvil]

I use CBN wheels from Schleif Junkies which are designed to run in regular water without any problems.  I have the 160, 400, and 1000.  I use the 160 strictly for reprofiling or repairing damaged blades.  Standard kitchen knives do very well on the 400 grit alone.  Nicer knives get the 400 and 1000. 

To me, this is the best of all worlds.  The wheels cut fast, they don't change size, they stay perfectly flat, and dust isn't an issue. 

As far as aggressiveness, they are like any plated stone or wheel.  For the first 5-10 sharpenings they'll act like much lower grits then they will eventually settle into.  My advice, if you don't have any beater knives to practice on, is to go to the grocery store and buy a pack of super cheap knives to use for break in.  I got a pack of 4 knives for less than $10. 

[Dontheo55]

Hello

I am new to the site but own 5 cbn wheels from Woodturners.  I have used them all in water with no problems.  Once I am done with a wheel I dry it off real good with paper towels.  I then leave them out in the open to air to dry before I put them back in the box they came in for storage.  Every once n a while I give the wheel a shot of WD 40.  Not on the cutting part of the blade but on the inner wheel and in the arbor.  WD stands for water displacement and is what the product was originally designed for.

[3D Anvil]

I don't understand why Woodturner Wonders' wheels can't be used in plain water.  I believe they say they are made from solid aluminum -- at least the Tornado wheels -- and electroplating is normally done with nickel, which doesn't rust.  They shouldn't be capable of corroding.