Safety: Most people know the common sense approach to power tools, but they don't always follow them.
People get excited or in a rush or just plain forget.
I know because I have done all three.
There is nothing quite like a runaway router bit or a kickback of wood to get your attention and remind you of an error in judgment.
Routers spin very fast and have a lot of power, so you have to take a few precautions to make sure your fingers and vital fluids stay where they belong.
You know them, but it doesn't hurt to remind yourself the easy way instead of the hard way.
This list is not complete but it is a good start.
1.
Safety glasses - Don't leave them lying on the bench, put them on and keep them clean.
You can't see your marks if they are full of dust, and you wont see anything if a wood chip damages your eye.
2.
Sleeves -Wear short sleeves or roll up your long sleeves above your elbow.
This isn't as big an issue when using the router hand held, but more so when it is mounted in a table.
It only takes a second to reach across the spinning bit and your sleeve is caught and pulls your arm into the bit.
3.
Unplug the router when you change bits.
It's a bit of a hassle but while your wrestling with the router and wrenches you could bump the switch.
At this point your fingers are the first to suffer, as the wrenches become projectiles.
What happens afterward is anybody's guess.
4.
When you tighten down the collet, make sure you have 80% or more of the shaft in the collet and that you have tightened it securely.
1/4″ shafts can bend if they are out too far, and when they do you will damage the material, the bit, the router and possibly yourself.
5.
Periodically check the condition of your router bits, especially if you drop one on the floor or bench.
Inspect the bearings, the brazing and the carbide.
A piece of carbide flying off at 22,000 rpm is not a nice thing.
6.
Nobody reads the owners manual.
It's boring, but every tool, every brand and every model is different.
It only takes a few minutes to read through and can save you time in the long run and help to avoid an injury.
Besides, then you'll know what that one mysterious knob on the side does.
Feed Direction The rule of thumb for feed direction is if you are facing the outside edge of your stock you want to move the router from left to right or counterclockwise.
If you are routing the inside edge, such as the inside of a frame, you want to move right to left or clockwise.
In both cases you are moving the router against the bit rotation direction.
This action keeps the router pulling into the material.
If you move the router in the same direction as the bit rotation, the router will tend to ride outward and try and run away on you.
One final suggestion is to start your edge routing on end grain, then with the grain, end grain and finally with the grain.
End grain has more of a tendency to chip as you are finishing the cut so by using this sequence you will have a better chance of avoiding any chip out.
Feed Rate There are two things to remember with regards to the rate of feed.
The first is to keep the rate as constant as possible.
Before you begin your pass, whether using a router freehand or on a table, place yourself so you can push either the router or material in a fluid constant motion.
Each time you stop during a cut you have more chance of causing a burn or a wave from pressure change.
These can be sanded out but it can be very difficult and time consuming depending of the species of wood.
The second is to adjust your rate of feed to the species of wood you are working with.
Generally speaking the softer the wood the faster the feed rate and visa versa.
So you would be able to feed fairly quickly on some pine, spruce or fir, but on oak, maple, or walnut you would have to slow down.
Router Speeds The rule of thumb here is the larger the bit or the harder the material, the slower the speed.
With the bit diameter, you have to keep in mind that the outside edge will be moving faster than the speed indicated.
You may think it won't be as effective by slowing it down but the cutter is still moving fast enough to provide a clean cut.
Don't forget, most shapers rotate at 10,000 rpm or less.
If your bit is less than 3/4″ or 1″ you can use the full speed of your router (approximately 22,000rpm).
For those bits between 1″ to 2-1/2″ reduce the speed to approximately 15,000 rpm.
For bits larger than 2-1/2″ use approximately 8,000 rpm.
These speeds are just to give you a starting place.
Adjust them according to the particular bit and material your working with.
For those with single speed routers, you just have to reduce the rate of feed.
Shaft Diameter Rule of thumb on shaft diameter is if the diameter of the cutter head is 3/4″ or smaller you are safe with a 1/4″ shaft bit.
Once a cutter is larger than 3/4″ it is too heavy and creates too much force to be safely used on a 1/4″ shaft.
There are large router bits like style and rail bits available which have 1/4″ shafts.
If you look at the weight and the amount of wood they are removing you realize the amount of force placed on that shaft and the heat, which can build up.
I have seen these bits bent at 45 degrees, and I don't like them.
Generally speaking, if your router accepts 1/2″ shafts buy all 1/2″ shaft bits.
The cost difference is usually small and the safety advantage is large.
If your router only accepts 1/4″ shaft bits try and stay away from the larger bits until you can upgrade to a larger router.
If you do use a large bit with 1/4″ shaft, pay attention, reduce cutter height per pass and slow the speed and feed rates.