Rick Hubbard
02-18-2009, 7:18 AM
RT Fence
After shelling out close to $800 dollars for a Benchdog cast-iron router table top and lift, I was not pleased when I discovered that I could not adapt my old fence to the new top (the router in my other table was offset from the center) and so I was faced with building or buying another fence. After looking at some of the commercial fences I decided buying one was not in the cards, so I decided to build a new one.
I began the project with a piece of extruded aluminum that has been kicking around my shop and garage for years. I have no idea what it is or where I got it, but as it turns out, I’m now glad I didn’t pitch it since it became the basis for a suitable (and inexpensive) alternative for a commercial fence.
The first thing I had to do was cut an opening in it for the router bit. That was quite a challenge since my metal-working skills are limited to cutting off bolts with a hacksaw (and that hacksaw also being pretty much the only metal working tool I own except for a couple of files). In any case, I performed the surgery by drilling a series of holes in a 3 ½ inch arc across the face of the extrusion, then chucking a metal cutting blade in my jig saw and cutting from hole to hole. I managed to break one blade but eventually finished the cut. Pretty it ain’t, but my thought was, after the MDF face is on it, who will know?
The extrusion itself is 1 inch thick with (as you can see from the pictures) a 1/8 thick by 1 inch wide tab all the way across the bottom. For the base of the fence I routed a 1/8 inch deep rabbet on the edge of a 5/4 X 4 inch piece of maple and screwed the extrusion to the wood “base” then checked it for squareness to the router table. I was flabbergasted to see that it was dead square (I had been thinking all along about ways I might use shim stock to bring it all into alignment (I should hasten to point out this is hardly a testimony to my skill- it’s more in the category of “dumb luck”). I also cut an opening in the wood base to allow for router bit clearance up to 3 ½ inches and drilled two more holes toward each end for the hold-down bolts.
Next I drilled four 11/32 holes all the way through the thickness of the aluminum extrusion to accommodate 5/16 inch T-slot bolts. That was pretty much the end of “metal-working” so then it was on to some more wood-working. T construct the fence-face my first step was to cut a piece of ¾ inch MDF to the same length and width as the aluminum extrusion. Then, using a 3/8 inch router bit, I ploughed a ½ inch deep groove into the face of the MDF so that it aligned with the 4 holes I had drilled earlier. After that, I used a T-slot bit to cut a T-slot along the groove in the MDF so I could attach it to the aluminum extrusion (I stole this idea from the $139 Bench dog fence).
At this point I started to get creative and experimental. I’ve always wondered if there was a way to incorporate replaceable inserts in a router table fence instead of using full length “sacrificial fences” when I need zero clearance for router bits. My “experiment” involved cutting the fence in half (at a point above the router bit) and cutting a tongue on the end of each piece of the fence. After cutting the tongue, I routed a matching groove in another piece of MDF so that it would slide in between the two haves and lock in place when the T-slot bolts were tightened. That seemed to work fine, so I cut some more inserts, so now I have an ample supply of easy-to-replace inserts to use when I need zero-clearance. The jury is still out on this
In order to accommodate hold-downs and a bit-guard for the fence, I did have to break open the wallet and buy a length Benchdog TopTrak which I screwed to the top of the aluminum extrusion with #8X1 ½ sheet metal screws space 2 inches apart.
My almost-last step in the project was to build a wooden box over the bit opening so I can hook up the DC hose to it. I still have one thing left to do- I need to buy 2 more 5/16x18 ratcheting knobs for the T-slot bolts that hold the wood face to the fence. At the moment I am using hex nuts on one end (that require a wrench to loosen and tighten).
The best part about this project is that my out-of-pocket-today cost was a little south of $25.
The question that remains, however, is whether the “replaceable insert” feature is going to turn out to be a “Boon” or a “Bust”. If it turns out to be a “Bust” I hope it’s not the kind of “Bust” that winds up with something exploding in my face!!!
After shelling out close to $800 dollars for a Benchdog cast-iron router table top and lift, I was not pleased when I discovered that I could not adapt my old fence to the new top (the router in my other table was offset from the center) and so I was faced with building or buying another fence. After looking at some of the commercial fences I decided buying one was not in the cards, so I decided to build a new one.
I began the project with a piece of extruded aluminum that has been kicking around my shop and garage for years. I have no idea what it is or where I got it, but as it turns out, I’m now glad I didn’t pitch it since it became the basis for a suitable (and inexpensive) alternative for a commercial fence.
The first thing I had to do was cut an opening in it for the router bit. That was quite a challenge since my metal-working skills are limited to cutting off bolts with a hacksaw (and that hacksaw also being pretty much the only metal working tool I own except for a couple of files). In any case, I performed the surgery by drilling a series of holes in a 3 ½ inch arc across the face of the extrusion, then chucking a metal cutting blade in my jig saw and cutting from hole to hole. I managed to break one blade but eventually finished the cut. Pretty it ain’t, but my thought was, after the MDF face is on it, who will know?
The extrusion itself is 1 inch thick with (as you can see from the pictures) a 1/8 thick by 1 inch wide tab all the way across the bottom. For the base of the fence I routed a 1/8 inch deep rabbet on the edge of a 5/4 X 4 inch piece of maple and screwed the extrusion to the wood “base” then checked it for squareness to the router table. I was flabbergasted to see that it was dead square (I had been thinking all along about ways I might use shim stock to bring it all into alignment (I should hasten to point out this is hardly a testimony to my skill- it’s more in the category of “dumb luck”). I also cut an opening in the wood base to allow for router bit clearance up to 3 ½ inches and drilled two more holes toward each end for the hold-down bolts.
Next I drilled four 11/32 holes all the way through the thickness of the aluminum extrusion to accommodate 5/16 inch T-slot bolts. That was pretty much the end of “metal-working” so then it was on to some more wood-working. T construct the fence-face my first step was to cut a piece of ¾ inch MDF to the same length and width as the aluminum extrusion. Then, using a 3/8 inch router bit, I ploughed a ½ inch deep groove into the face of the MDF so that it aligned with the 4 holes I had drilled earlier. After that, I used a T-slot bit to cut a T-slot along the groove in the MDF so I could attach it to the aluminum extrusion (I stole this idea from the $139 Bench dog fence).
At this point I started to get creative and experimental. I’ve always wondered if there was a way to incorporate replaceable inserts in a router table fence instead of using full length “sacrificial fences” when I need zero clearance for router bits. My “experiment” involved cutting the fence in half (at a point above the router bit) and cutting a tongue on the end of each piece of the fence. After cutting the tongue, I routed a matching groove in another piece of MDF so that it would slide in between the two haves and lock in place when the T-slot bolts were tightened. That seemed to work fine, so I cut some more inserts, so now I have an ample supply of easy-to-replace inserts to use when I need zero-clearance. The jury is still out on this
In order to accommodate hold-downs and a bit-guard for the fence, I did have to break open the wallet and buy a length Benchdog TopTrak which I screwed to the top of the aluminum extrusion with #8X1 ½ sheet metal screws space 2 inches apart.
My almost-last step in the project was to build a wooden box over the bit opening so I can hook up the DC hose to it. I still have one thing left to do- I need to buy 2 more 5/16x18 ratcheting knobs for the T-slot bolts that hold the wood face to the fence. At the moment I am using hex nuts on one end (that require a wrench to loosen and tighten).
The best part about this project is that my out-of-pocket-today cost was a little south of $25.
The question that remains, however, is whether the “replaceable insert” feature is going to turn out to be a “Boon” or a “Bust”. If it turns out to be a “Bust” I hope it’s not the kind of “Bust” that winds up with something exploding in my face!!!