Many wood routers have adjustable speeds and some are single speed routers. Knowing the maximum manufacturer’s recommended speed for your router bits is a very important safety measure that should never be ignored. Not only is speed a safety concern, it will affect the quality of your work as well.
Most manufacturers have a tech support line or a website with router bit speed information. If your router bit maker doesn’t offer such information, you should consider using a better router bit. In case you are in need of such information however, we will supply you with the most popular ones here:
- Bits with a diameter of 1 inch should not exceed 24,000 RPM.
- Bits with a diameter of 1.25 to 2 inches should not exceed 18,000 RPM.
- Bits with a diameter of 2.25 to 2.5 inches should not exceed 16,000 RPM.
- Bits with a diameter of 3 to 3.5 inches should not exceed 12,000 RPM.
As you can see, generally, as the diameter of the router bit increases, the maximum recommended RPM decreases. This is simply because the routers speed is measured at the shaft and if the bit has a wider diameter, the speed increases the further away the edge of the bit gets from the center of the shaft.
Most variable speed routers have a red knob that adjusts the shaft speed. If you do not see one of these, you most likely have a single speed router. If you have a single speed router, check the documentation to find out what the maximum speed is for your router and do not use bits that cannot handle that speed. For example, if your router is rated at 23,000 RPM, do not use a bit that says not to exceed 16,000 RPM.
The direction in which your feed your wood stock into a router is crucial. One mistake can cause serious injury. Fortunately, the rule of thumb is that the wood stock always moves against the rotation direction of the bit, not with it.
If you feed the stock in the wrong direction, with the rotation of the bit, the bit may quickly propel the wood out of your hands. If this happens, your hands are in serious danger if moving into the bit uncontrollably, causing serious injury and even disfigurement. Some routers will have warning stickers with an arrow indicating the feed direction. Take these warnings seriously and never feed your wood from the wrong direction.
If you are using a hand held router then you need to pay particular attention to the feed direction. The best practice to avoid feed direction errors is to always start at the same spot on a piece of wood when routing the outside edge.
For example, you can always start from the bottom left because from the perspective of holding the router, the bit should be spinning clockwise. Knowing that, you should be able to figure out that it is safe to start on the bottom left and move to the right around the perimeter of the piece of wood. Likewise, if you are doing an inside edge, you would start at the upper left corner of the opening and again go to the right.
Direction of the Wood Grain
Along with the feed direction, the direction of the wood grain is another very important factor when using your router. When feeding your wood into the router, you need to make sure not only that you feed the wood against the router’s bit direction, but also you want to feed it with the wood grain direction.
To picture this imagine the router bit spinning against the grain, which is the wrong way. If it were spinning against the grain, it would lift up a portion of the wood and splinter it off making for an uneven surface. Basically, the grain should slope away from the cutting edge of the bit so that it doesn’t catch on the wood grain and splinter.
Sometimes, the wood grain can be difficult to read because it may appear to run at a right angle to the edge, making hard to tell. In this case, sometimes the only way to tell for sure is by trial and error. If you choose the wrong way, it will cause a rough edge, whereas if you choose the proper direction, you will have a nice clean cut with a smooth edge. Luckily, most of the time the wood grain is fairly easy to read and runs fairly parallel to the wood edge. Then all you need to remember is that the grain should slope away from the cutting edge, not into it.