How to Keep your Grinding Wheels Performing Every Time
Grinding wheels are a very important tool in many factory and shop situations. They can be used for any number of projects; because of this, they tend to become something that are taken for granted. You expect that when you go to the shop that the grinding wheels will work as intended.
However, there are a number of issues that can occur that prevent the wheels from grinding as they should. While some of these problems are big and require a replacement wheel, others are reparable. One of the most common problems is a wheel that is not providing as heavy of a grind as it should.
Commonly, new wheels may not have the same grinding power as wheels that have been “broken in” and used for some time. As such, it is important to understand the concept of dressing grinding wheels.
To get the best cutting performance from your grinding wheel it is important that the wheel have a sharp abrasive grain with cutting points that are well exposed and able to connect with the piece with which you are working.
The ultra-hard abrasive crystals often used in grinding wheels will remain sharp simply through the process of grinding itself. Essentially, the wheels will slowly expose further crystals and you will not need to continuously dress the wheel. This is one of the biggest benefits of these superabrasive grinding wheels.
However, one problem is when you are working with new wheels. Usually these wheels have a smoother grinding surface. This occurs because the crystals and the surrounding bond are still flush to the edge of the cutting surface. If you try to operate a wheel without first dressing it, you will find performance is lacking. This is called “loading.” A wheel that is loaded will have poor cutting performance and may even cause some burning to your work piece.
This is where dressers come in. Diamond dressing sticks or rotary diamond dressers (also known as diamond rolls) are supplementary tools that keep your wheel operating at peak performance.
Dressing your superabrasive grinding wheel enhances grain exposure and brushes away some of the bond so that the wheel will work as it should. However, it is important that you choose the right type of dressing for your wheel to get the performance you desire. Some of the qualities you should consider with your grinding wheel dressing include:
Hand held aluminum oxide or silicon carbide stick
Soft (G, H hardness)
Fine grit (200-400 mesh)
Another strategy is to lower the RPM of the spindle, at least temporarily. This will open the wheel quicker and expose the abrasive surface for a more open surface. Then, you can increase the RPM in the future when the abrasive surface has been properly dressed and exposed.
While dressing your wheel is often something that only occurs when the wheel is new, it is possible to experience burning and poor cutting even on an older wheel. If this happens, you can simply use the same stick and technique to re-expose the surface and reopen the wheel.
As you can see, there is a lot to think about when you are first setting up your grinding wheel or if you are working with a wheel that does not seem to offer the best performance. It is possible to get the performance you desire it just takes a little work and effort up front!