Drilling for Dowels:
Companies who purchase many dowels sometimes have to sort the dowels by size. They usually get some undersize, some on size and some oversize. Then they match the dowels with one of three sizes brad point drills saved for that purpose. Two of the drills are specially made to cut .010" undersize and .010" oversize (at a cost of about $35 or $40 each). Unless you are making your own dowels, you cannot control the size variations you get from anyone.
What actually causes wood to burn?
Burn is caused by excessive heat. Heat is caused by friction. Friction is cause by the tool rubbing against the wood instead of cutting.
A little info on Forstner Bits:
Believe it or not, a true Forstner Bit is designed to rub on the wood. The rim around the outside of the Forstner bit acts as a guide to keep the tool centered. The Forstner Bit is designed to be able to cut half hole on the edge of the wood or cut on a angle. Most tools have some type of point in the center the guide them. A true Forstner Bit, like the ones made by Connecticut Valley Manufacturing, do not have center points. A good Forstner Bit works well in softer wood but heats up in harder woods. A cutter with saw teeth around the outside edge is best for hardwood (all cutting, no rubbing).
The Brad Point can also be a problem with some of these bits in hard wood, even the ones with saw teeth around the outside. If the brad is too fat at the base, it will cause heat by rubbing (which is what a brad point does). A thick Brad point can also cause the tool to have to be pushed too hard to get it to cut.
Can you read your cutting tools?
Here is a tip about cutting tools. If you are have trouble getting a tool to cut, you push but the tool just doesn’t want to bite into the material. The tool rubbing against the material will quickly cause heat to build up and even cause the material to burn and stick to the tool. The tool could get hot and start to turn blue. Stop and take a good look at the tool. If you find an area that is burned, you will find an area just ahead that is shiny. The shiny part ahead of the burn is the part of the tools that is rubbing instead of cutting. You might find one tooth rubbing on a multi-tooth tool. You might find the heel of the cutting edge rubbing instead of the toe. You might find that the outside diameter of the tool is burning which could be a sign that the diameter of the tool at the cutting edge is smaller and the rest of the tool and will not follow the cutting edges into the hole without rubbing. Learn to read your cutting tools.
Tiny Plug Cutters
Although the smallest plug cutters that Fuller manufactures is 1/4”, it is possible to use another one of their products to cut small diameter plugs. Their Type ‘J’ Countersinks can be used to cut wood plugs from 3/32” up to 3/16” in diameter. The Type ‘J’ countersinks are similar to their plug cutters except the hole goes all the way through the shank. W. L. uller, Inc. does not market these tools as being able to cut plugs because it is very difficult to cut small plugs. The plug have a tendency to break apart inside the cutter. Success greatly depends on the type of wood being cut. The harder the wood the better. We do know that a number of customers have had success with these cutters.
What to do if your Fuller countersink slips up or spins around the drill it is mounted on:
The Fuller HSS Taper Point Drills are made from the best quality High Speed Steel and carefully hardened to stand up in hardwoods, yet resist breaking in tough drilling conditions at the same time. Because of this hardness, it is sometimes difficult for the locking set screws to get a good grip on the drill. Slipping only happens in extreme circumstances in which the material being cut is very hard, the cutting tools are dull or the cutting tools are being pushed too hard. The Fuller countersinks are designed so that the locking set screws tighten into the flutes of the taper point drill. This will prevent the countersink from spinning on the drill. However, it may not stop the countersink from slipping up the drill to the end of the flute section and you may not be able to accomplish this if the countersink needs to mounted with the set screws tightening on the shank of the drill because of the drilling depth.
There are a number of things that can be done to eliminate slippage:
1. Small flat spots can be ground into the drill at the point where the locking set screws come into contact. This eliminates both slipping and spinning.
2. When ever possible, insert the drill far enough into the chuck so that the countersink is up against the chuck. It may help to cut off the shank end of the drill bit so the countersink can rest against the chuck.
3. If there is enough room on the drill, mount a second countersink upside down behind the first countersink. Now you will have four locking set screws instead of two. You can also use a Fuller drill stop instead of the second countersink.
4. Use Fuller splined set screws and splined keys. These screws and keys can not be rounded over. The set screws can be turned much tighter. These screws are available here on this site.
High Speed Steel Countersinks are Breaking in Wood
High Speed Steel Countersinks (HSS) are designed to cut metal but are widely used to cut wood because the cutting edges last longer in tough materials like plywoods and hardwoods. They can only be used to coutersink screws flush with the surface. The HSS countersink have shorter flutes and will not cut deeper for plugging.
Because the HSS countersinks are very hard, they are subject to breakage if not mounted properly on the drill bit. The most common problem occurs when the countersink is mounted too high on the drill bit, allowing the point of the drill to break though the back side of the material before the countersink starts cutting. This causes the countersink to jam into the material as the drill bit breaks through the back side of the material. The HSS countersink should be mounted on the drill bit so that it begins cutting before the drill bit breaks through the material.
