small CB Borazon grinding stone

"Karl Townsend" wrote in message news:dPZ1h.649$ snipped-for-privacy@newsread1.news.pas.earthlink.net...

Karl, are you SURE that wood isn't dirty? I can cut aged oak all day long on a single sharpening of my off-the-shelf Oregon chains.

Even a little sand will halve that.

LLoyd

AFAIK, diamond on steel don't work. The diamond just burns up. The borazon wheels were the answer to that isue

Its a standard chainsaw sharpener, made by Sears, but I thought more folks would know what a Dremmel is.

Karl

Not directly answering this question, but... A gizmo I got some time ago is a hardfacing kit called the "TungCarb" by Bebe Mfg. I don't have a web address for them. It has a modified Dremel electric engraver and a "power supply" pod. You clip the ground clip to the work, and apply the carbide rod on the engraver to the cutting edge. It works to extend the life of the edge on end mills, and I even tried it on a lawnmower blade. It worked well in both applications. It never ocurred to me to try in on chainsaws.

Jon

That's correct. Diamond is absorbed by iron based alloys when run at red heat, which is happening at the point of contact.

Dremmel is likely part of the problem. Abrasives should be run at speeds that approach 6,000 SFPM in order to perform as designed. When you run them slower, they behave softer and self destruct much more quickly. The old rule of the harder the material the softer the wheel, and vice-versa holds true. That means that in order for a 7/32" diameter to run at a speed that allows the wheel (they're mounted wheels, not stones) to run at proper speed, your Dremmel would have to be running at approximately 105,000 rpm.

I don't think so!

Harold

At work we turn a lot of steel bores using diamond. Surface finish is the reason, very light one pass cut. Diamond seems to last.

Is that because we are not taking heavy cuts? You mentioned red heat.

The borazon thing, is this the same as a CBN wheel? I've collected a few that were worn too small for our applications. Figured that they might be good to have some day. Do they have to be run with coolant or will they work dry?

Thanks,

Wes S

mcmaster carr- cbn jig grinding points prt # 4338a11- 6.39 in catalog#104 Pat

Dang!

I feel dumb for not looking here. McMaster has everything. Thanks for the tip. With their service, it will be here by tommorrow morning.

Hey Karl,

Many of the Dremel accessories using stone are now also produced with the same form and size using diamond coating. Worth a try?

And not arguing about what you are using, but it may be worth asking the chain supplier for a few ideas, both in method and tools.

Take care.

Brian Laws>I'm still spending 1/2 my time cutting wood. And the other 1/2 sharpening

I would imagine it lasts fairly well, but you're likely experiencing miniscule absorption at the point of contact, assuming the chip is coming off red. As I recall, diamond isn't recommended for machining iron (or steel) any more than grinding, although that doesn't mean it won't work. When you hit a resinoid bonded wheel with steel, it doesn't take very long for the wheel to begin to slip instead of cut--and needs to be cleaned, or dressed. The surface of the wheel is altered ever so slightly, exposing new, sharp diamond grains.

Yes, I feel that's the difference. It's long been known, at least since the

As I understand it, yes, that's what they are. Cubic boron nitride. CBN. I believe that's Norton's name for their version.

I've collected a

I would assume they are bonded by means that requires cooling. Best to check the recommendations of the manufacturer. If they're set in nickel, could be they can be run dry. Keeping any wheel cool is a good idea, and it's generally better for the item being ground, too.

I'd like to note that CBN wheels were introduced to industry long after I left the shop, so I have no experience with them.

Harold