C.B.N. coated for T7

[grepper]

http://www.d-waytools.com/tools-diamond-grinding-wheels.html

The subject of CBN on Tormek is certainly not new.  Here's some discussion from 2 years ago:
http://www.woodworkforums.com/archive/index.php/t-176064.html

10" x 2" for Tormek
http://woodturnerswonders.com/products/tormek-cbn-wheel-600-grit-10-x-2-inch-1-2-inch-arbor

[Ken S]

Interesting, Grepper.

Dave Schweitzer (D-waytools) was the guy I emailed for info. The last email question, not previously posted here was about the availability of CBN wheels for the T4. His answer is that they do sell wheels for the T4. He added that the orders need to be by telephone, as the 12mm modification is not listed on the website.

My "Popular Mechanics Home Workshop" adaptor for grinding wheels with a 5/8" smallest shaft opening is to start with a short piece of Schedule 80 plastic water pipe. (The Norton 3X wheels come this way and Norton will not sell the half inch bushing separately "for safety reason". I tried calling them.) It has a 5/8" OD (outside diameter) and a 7/17" ID (inside diameter). I put a 31/64" drill bit in the drill press and using the slowest speed drill out the pipe to that size. A 12mm drill bit would probably be better, but i don't live in Metricland. Cut the piece to length (thickness of the wheel) and slide into place.

I have not measured the run out with this set up, and I am not too worried about it. It is certainly within tolerance for coarse work. A machined steel bushing would be better. I would use one of these bushings with a CBN wheel. In the case of the Norton wheels, I was looking for an inexpensive solution for my very occasional use.

With the 600 grit CBN wheel, my question is how cost effective is it? Chicago has a saying, "vote early and often". If you true the SG wheel early and often, and lightly, it does not require much time, and you know you are true. I can see the benefit of a coarse wheel, either 3X or CBN, as Tormek does not manufacture such a product, and they do work. While the 600 grit wheel may have some advantages, it seems very close to the Tormek wheel we already have.

[Herman Trivilino]

Last question:  They're made of steel right?  Then the abrasive is electrolitically applied??? 

I think, but don't know, that the finish is applied with a more sophisticated technique than electroplating. I remember as far back as the 1990's researchers in the field of surface physics were promising great things. They are able to bond things to the surface of other things with incredible precision. The bonding is done at the molecular level and is quite strong. They promised things like ball bearings that needed no grease, stayed cool, and lasted forever. I'm still waiting to see that achievement!

[Herman Trivilino]

I've thought of another too.  You cant true them right? 

Right, so presumably that's done at the factory to the steel substrate before the cBN is applied. But that won't address issues arising from the universal support rod not being parallel to the axis of the grindstone rotation.

[grepper]

The better wheels are electo-less nickel plated with a thickness of .0001 - .003.  It is more even layer and more corrosion resistant than electroplated nickel.  It is however not as hard as hard chrome, but more corrosion resistant.  Depending on the nickel alloy used such as boron and varying percentages of phosphorous, heat treatment after application can achieve HRC hardness of up to 70 and around 55 prior to treatment.

Combined with CBN abrasives, this produces an extremely tough and uniform distribution of abrasive on the surface of the wheel.

And check this out.  You can do it yourself!
http://www.caswellplating.com/electroplating-anodizing/nickel-plating-kits/electroless-nickel-plating-kits.html

Or better yet... tougher than nickel:
http://www.caswellplating.com/cobalt-standard-plating-kit-10-pint.html

[Elden]

10" x 2" for Tormek
http://woodturnerswonders.com/products/tormek-cbn-wheel-600-grit-10-x-2-inch-1-2-inch-arbor

   The troubling thing that I notice, it is stated that it is for the Tormek yet has a 1/2" bore. The Tormek uses 12mm (0.4724").

0.500" - 0.4724" = 0.0276"

    In the machining world, that is a lot of tolerance (slop). That would be something to be checked out more closely for someone actually considering that option. It may be that they actually have a 12mm bore available upon contact with them.

[Ken S]

Eldon,
They are available with 12mm bores. (Ah ha,"bores" is the correct term.) D-way has them available in 1 1/2" width with 12mm bores for either eight or ten inch diameter.

The homemade method I described using plastic pipe seems adequate for occasional use with a 3X wheel, but I would want a more precise bore for a CBN wheel.

Ken

[Herman Trivilino]

The troubling thing that I notice, it is stated that it is for the Tormek yet has a 1/2" bore.

If it really does have a 1/2" bore it won't work on the Tormek. My guess is that the 1/2" is nominal, but I would get that clarified before I ever paid for one. Also, the disclaimer concerning guard removal is not consistent with it being made for a Tormek.

[grepper]

I would want to check if those particular wheels are plated or matrix composite.  It says on the site they are made from aluminum, not steel.  Sure looks like it's plated, but I would want to verify if it is electroless nickel plating.  Electroless nickel works on aluminum, but I would want to make sure.

You don't want to get matrix composite, as it will dish.

[Rob]

you know I've been thinking about these CBN wheels and the one use that really waves a flag at me is pairing it with the svh-320 to do tricky planar blades.  The primary problem I experienced before (with the SG) was that to keep the stone cutting I had to re grade constantly.  In the end, the only method of regarding that got it rough enough to really cut was a true with the diamond dresser (you know how rough that makes the wheel).  That would then cut my ultra hard Startrite knives for a minute or so. Of course what then happens with the constant need to regrade to bring back the cutting of the wheel, the wheel diameter is reduced which throws out the precision settings of the jig.  The efficacy of the planar jig is critically dependent on very fine settings.

With the CBN wheels they should provide two solutions to the challenge:  1) they don't wear down at all and 2) they're more abrasive and should therefore cut better than the standard approach.

[Ken S]

Rob, you bring up an interesting issue. While the planer jig seems well designed, several posters, including you, have grumbled about poor sharpening with it. I can't imagine Tormek going through the expense of designing and marketing a jig without first making sure it worked well. So, what is the missing link?

This returns me to my long spoken grumble about the lack of training material. I am not certain, but I believe the planer jig was designed before the SB wheel. Surely the engineers would not have approved the jig unless they were able to sharpen planer blades in a reasonable time. There must be a missing piece in using the jig that we do not know.

Tormek, would you please let us know the missing piece of using the planer jig efficiently.

Ken

[Rob]

It's exotic alloys Ken.  Some planar knives are simply harder than others....much harder in fact. Some I believe are even a laminated type steel more akin to expensive Japanese techniques.

The softer ones seem to work with the Tormek setup but not the harder ones.

[Herman Trivilino]

Ken as you know better than me, new alloys are being used for many of the woodworking tools that we sharpen with the Tormek. Jigs designed in prior decades may not work as well as designed with some of these new harder alloys.

Rob, you keep adding these items to your sharpening arsenal. You have a premier set up and could easily go into the sharpening business. One of the things that will help is your location in and near large population centers. Plenty of customers.

[Ken S]

I agree, Herman. However, is the problem the jig or the mismatch of grinding wheel and exotic alloy? The jig itself seems well designed to me. Allen recently posted an interesting post about sharpening the blades from a Lion Trimmer with the planer jig. The Lion Trimmer is a century old stalwart guillotine trimmer for trim and picture frames. Due to the age of the design and the need for the keenness of edge only carbon steel can provide, I suspect these blades must be carbon steel. They need sharpened more often, but can be very sharp, due to the fine grain structure of carbon steel. Any follow up, Allen?

For many years I had a small, very small, part time photography business. I specialized in custom black and white processing. I liked to work "in house", but realized that some jobs were better done by a commercial lab. I had a couple jobs requiring 16x20" framed color prints. As my darkroom was primarily set up for black and white and the one job called for the two large prints to be framed in the same frame (my mat cutter could only handle mats up to 40"), it was more cost effective for me to deal with a commercial lab and a framing shop. I think the same might apply for most of us with occasional exotic steel sharpening.

Certainly regularly sharpening several sets of planer blades each week would warrant the investment in specialized equipment. However, sharpening one's own planer and jointer blades a couple time a year might be best contracted out if they are an exotic metal.

Ken

[Rob]

the problem here though Ken is that it's only after one has shelled out the £120 for the jig that you "find out" they don't really deal with ultra hard steels.  It's the same old same old....the marketing folks just plaster all the promotional collateral with "why use an expensive service when you can sharpen your planar knives yourself".  But these days more and more machine tools that deal with man made materials and procedures at high speed have steels that are way harder than carbon steel.  Harder than HSS in some cases.

The marketing folks don't factor those scenarios into their collateral because "it works....some of the time" doesn't sound quite as snappy!  Or....."it can work, but we're not going to tell you when it doesn't work because we're people people and people people always phrase things in the positive"

Or as I might phrase it: "our engineers have created a jig which can give outstanding results.  For that to occur, certain variables must be met, it is possible that your setup won't meet those variables but by specifying what they are might cause people to lose confidence in the solution and consequently fail to purchase it.  Were that to happen, our job would cease to exist since we are accountable to the exec for creating "desire" in our potential customers.  Since we value our jobs more than our customers it is important we neglect to mention all that inconvenient "truth" stuff."

Although that may well land me with the title of being rather cynical :-)  As Oscar Wilde said: scratch the surface of a cynic and you'll find an idealist beneath :-)