CBN grinding wheels have been around for some time now and they have fast become a favorite among flywheel grinding technicians. CBN stands for Cubic Boron Nitride. CBN is as close as you can come to having a diamond grinding stone. It’s because of this hardness that these grinding stones are becoming so popular.
The CBN Grinding Wheel Advantage
Probably the best part is that they last longer. On average, you can expect a CBN grinding wheel to last about 10 times longer than a comparable standard flywheel grinding stone. They have and hold their balance extremely well. This allows them to be more precise and repeatable. They produce less debris than a traditional stone so your coolant stays cleaner longer.
Getting the Best Results Using a CBN Wheel
A CBN wheel requires a bit more downward pressure to perform well, so be sure to give it the go. Use a CBN Dresser Stick to keep your CBN wheel performing at its peeks. Be sure to use clean coolant at all times. And use plenty of coolant where you are cutting.
Keeping Your Cool
A good quality coolant is very important. Many come as a concentrate that you mix with water which seems counter-intuitive since you don’t want to promote rusting. Having the right ratio of coolant concentrate to water is very important. You’ll need to try varying the mix to get what works best for you. Use the mixture abundantly on your work peice. A good flow of coolant keeps debris away and keeps your stone cutting at its optimal pace.
And Keeping It Clean
Flywheel grinding is a dirty, messy business. Taking the extra time to wipe up and maintain your machine will make a huge difference to the longevity of your flywheel grinder. A good trick to help keep your coolant clean is to get a magnet the size of a hockey puck and place it in the bottom of your coolant reservoir. This will attract and hold the metal shavings out of your coolant as it recirculates and allow you to not only go longer between changing coolant but also have cleaner coolant flowing over your workpiece.
Doing the Grind
We recommend that you start with your grinding wheel just above the surface to be ground. Get the grinder spinning at full speed and then lower it onto the surface. Once you touch down, feed the head down about .001″ to .002″ per rotation of the flywheel. Don’t pause for the wheel to “spark out” while you are grinding. Once the entire surface you are grinding becomes clean then back your wheel off about .0008″ to .001″ and now let it spark out for a beautiful finish.
You’ll get a consistent finish easily with CBN wheels. Use coolant when grinding flywheels and floaters and grind discs dry. Top fuel teams that use CBN wheels have proven this method is the one that works time and time again.
Dressing for Success
With a CBN wheel, you might feel it’s never necessary to dress the wheel, but that just isn’t the case. It’s true that you should not use the same dressing method that is used on a traditional stone. CBN wheels are dressed with a dresser stone. You hold the stone about a 10 degree back angle to the face of the CBN wheel while it’s spinning. Just a few seconds is all it takes. If your wheel still squeals when you are grinding try using a bit more force. As I mentioned before, you need to be a bit more aggressive when grinding with a CBN wheel.
As you can tell, the CBN grinding wheel is the grinding wheel of the future and it’s available today. Lasting 10 times longer, creating less debris, and producing the best possible finish is the least amount of time, why wouldn’t you use one? OK, yes, they are a bit costly to purchase. However, if you really look at the numbers those only stone wheels are actually costing you more money and spending more time cleaning means less time actually producing. So the CBN really is not more expensive than traditional grinding stones.
I hope this has helped you and you are now ready to jump in with both feet and switch to using CBN wheels. Here’s a link to where you can get all your flywheel grinding supplies including CBN wheels at a very competitive price.