Steve Maskery
Established Member
Several years ago, when I was filming my DVD series, I made a secondary fence for my tablesaw which was designed to help when using the tablesaw to cut rebates or grooves, such as as you might have for a cabinet back.
It worked very well, but it went into storage in a barn for a couple of years and didn't come out again. I now have a particular use for it, so it is a good opportunity to make a new version which also happens to improve on the original.
The important thing about a groove or a rebate is that is is the same depth all along its length. I don't want it to be shallow in one or two places because the workpiece has risen up above the blade. It also has to be straight, not slightly wonky because the workpiece has wandered away from the fence. This fence addresses both these issues.
It consists of an MDF fence which clamps to the main saw fence. There are two featherboards, one just in front of the blade and one just after, as well as an adjustable guard, which keeps my fingers and the saw blade apart, even when there is no workpiece between us.
The original featherboards were cut straight at 90 degrees, but I figured that if I angled them in the right direction, I could get them to pull the workpiece in towards the fence as well as down onto the table. This turned out to be easier said than done!
My first attempt was to cut the shape, rout the slots and then make a series of stopped cuts on the tablesaw to give me a set of fingers, all cut from one solid piece of wood. Unfortunately I had got the geometry wrong in my head, so I ended up with a fine-looking featherboard that pushed the workpiece AWAY from my fence, the exact opposite of what I was trying to achieve.
This happened because my tablesaw tilts to the right, towards the fence. If I had a modern design where the blade tilts left away from the fence, all would have been well, but that is not the situation in which I found myself.
The idea remained a good one, however, so I simply had another go. I cut a load of individual fingers and spacers and glued them together, but whilst it worked properly at the end, it was a nightmare to glue up, because the fingers slid sideways over one another as I applied pressure across. Keeping it all flat was very difficult.
There had to be a better way and I went back to the original idea of cutting a series of kerfs in a solid piece. And if tilting my blade to the left isn't an option, the workpiece must be tilted to the right.
The Jig.
I made a jig. Well that is a rather grand term for three pieces of scrap, but it'll do. I took a piece of OSB, about 400mm x 180mm, attached a runner underneath the left-hand edge and a lip along the right-hand edge. These were glued and screwed, but the screws come out once the glue has cured.
With the screws out, I ran the jig over the surface planer to give me two flat areas, and trimmed the lip so that it had a vertical side.
The featherboards.
I started with a board long enough to make both featherboards. This gives me plenty to get hold of instead of trying to make stopped cuts on a very short workpiece. I marked out where the slots were going to go, as well as the limits of the fingers.
The featherboards need to be adjustable in height to accommodate different thicknesses of workpiece, so the first task was to rout the slots in the edges of the featherboards.
This is done by “dropping on”, which means lowering the workpiece onto the cutter while it is already spinning. It's not the easiest of operations tp perform, but it can be made a lot easier and safer by clamping a couple of stops to the router table.
If the stop needs to be off the end of the table, I can clamp an OSB hook to the fence instead of a block of wood to the table. It does the same job.
Starting with the workpiece hard against the rearmost stop, it is lowered onto the cutter and pushed forward until it hits the end stop.
I cut the slot in several passes. The first pass, in particular, needs to be very shallow indeed, because there is nowhere for the sawdust to go. Thereafter there is at least some space in the existing groove to take the sawdust. I continued, taking not more than 3mm per cut (it is all too easy to snap a 6mm cutter), until I had broken through the top surface.
The second pair of slots requires me to alter the stops, but the fence stays where it is.
It worked very well, but it went into storage in a barn for a couple of years and didn't come out again. I now have a particular use for it, so it is a good opportunity to make a new version which also happens to improve on the original.
The important thing about a groove or a rebate is that is is the same depth all along its length. I don't want it to be shallow in one or two places because the workpiece has risen up above the blade. It also has to be straight, not slightly wonky because the workpiece has wandered away from the fence. This fence addresses both these issues.
It consists of an MDF fence which clamps to the main saw fence. There are two featherboards, one just in front of the blade and one just after, as well as an adjustable guard, which keeps my fingers and the saw blade apart, even when there is no workpiece between us.
The original featherboards were cut straight at 90 degrees, but I figured that if I angled them in the right direction, I could get them to pull the workpiece in towards the fence as well as down onto the table. This turned out to be easier said than done!
My first attempt was to cut the shape, rout the slots and then make a series of stopped cuts on the tablesaw to give me a set of fingers, all cut from one solid piece of wood. Unfortunately I had got the geometry wrong in my head, so I ended up with a fine-looking featherboard that pushed the workpiece AWAY from my fence, the exact opposite of what I was trying to achieve.
This happened because my tablesaw tilts to the right, towards the fence. If I had a modern design where the blade tilts left away from the fence, all would have been well, but that is not the situation in which I found myself.
The idea remained a good one, however, so I simply had another go. I cut a load of individual fingers and spacers and glued them together, but whilst it worked properly at the end, it was a nightmare to glue up, because the fingers slid sideways over one another as I applied pressure across. Keeping it all flat was very difficult.
There had to be a better way and I went back to the original idea of cutting a series of kerfs in a solid piece. And if tilting my blade to the left isn't an option, the workpiece must be tilted to the right.
The Jig.
I made a jig. Well that is a rather grand term for three pieces of scrap, but it'll do. I took a piece of OSB, about 400mm x 180mm, attached a runner underneath the left-hand edge and a lip along the right-hand edge. These were glued and screwed, but the screws come out once the glue has cured.
With the screws out, I ran the jig over the surface planer to give me two flat areas, and trimmed the lip so that it had a vertical side.
The featherboards.
I started with a board long enough to make both featherboards. This gives me plenty to get hold of instead of trying to make stopped cuts on a very short workpiece. I marked out where the slots were going to go, as well as the limits of the fingers.
The featherboards need to be adjustable in height to accommodate different thicknesses of workpiece, so the first task was to rout the slots in the edges of the featherboards.
This is done by “dropping on”, which means lowering the workpiece onto the cutter while it is already spinning. It's not the easiest of operations tp perform, but it can be made a lot easier and safer by clamping a couple of stops to the router table.
If the stop needs to be off the end of the table, I can clamp an OSB hook to the fence instead of a block of wood to the table. It does the same job.
Starting with the workpiece hard against the rearmost stop, it is lowered onto the cutter and pushed forward until it hits the end stop.
I cut the slot in several passes. The first pass, in particular, needs to be very shallow indeed, because there is nowhere for the sawdust to go. Thereafter there is at least some space in the existing groove to take the sawdust. I continued, taking not more than 3mm per cut (it is all too easy to snap a 6mm cutter), until I had broken through the top surface.
The second pair of slots requires me to alter the stops, but the fence stays where it is.