[Stokestack]

Hi all.

I'm running a long, thin piece of wood across a chamfer bit to give it a sloped edge. I'm cutting away the entire edge of the board, so the pilot bearing is not making (and can't make, for this application) contact with the wood.

Of course, as the wood travels along the right side of the fence and its edge gets cut away, it doesn't meet the left side of the fence. Thus, when reaching the end of the board (and it is several feet long, much longer than my little Bosch table), I have no way of keeping the thing straight as I drag the last few inches of it across the bit.

Of course this same situation will occur any time you're cutting away the entire edge of a piece on the table, so what is the solution?

Thanks!

 

[Bob Adams]

Personally I would make that cut at the table saw. It doesn't look like your router table has a split fence, so you might be able to cut some scrap, and place it on the out feed side to support the cut. But really the safest is the table saw.

 

[DesertRatTom]

You need a featherboard to push the piece into the fence. I'd suggest having one before the bit, and one after. Need not be at an angle on the one after the bit so long as it's pressed against the bit.

The other thing I'd do is put a featherboard on the top, pressing down as well. If you're using a commercial featherboard, note that the first "tooth" is shorter than the rest. LIGHTLY press that short tooth agaist the workpiece and the rest will apply proper pressure.

If you don't have a T-track to mount it on the fence, you can clamp it on instead. If you don't have a T-track on the table, you can use a long, open mouth clamp to clamp one down as well. The picture shows the really wide featherboards, which will be easier to clamp to the table top. You can buy these anywhere. I'd also prefer to cut this on a table saw, still using a featherboard.

 

[Cherryville Chuck]

Use double sided tape or a few drops of hot melt from a glue gun to attach another board on top of the one you’re cutting it acts as a guide then so that you don’t snipe the last bit.

 

[Hypnotoad]

Another way to do it is to move the fence back to the width of the piece you are machining, you then turn the piece around and feed the piece in from the left side of the table to prevent the bit from pulling the timber along with it, the timber goes between the fence and the router bit, use feather boards to keep the piece against the fence. Make sure you use push sticks and/or push pads when doing this.

This is what I do when I want a piece dressed on the edge of a certain width, cut it a mm or two wider on the table saw then take the excess off on the router table.

 

[woodknots]

Or, route just a small portion of the board, then if your fence is split and the outfeed fence can be shimmed, shim it until it touches the work piece, then continue routing while the outfeed fence is supporting the work.

I was looking for a video from the New Yankee Workshop series on routers - go to the 2:00 minute mark for a video of what I was trying to describe

 

[Stick486]

move the fence forward for a zero offset...
add a piece of material the thickness of the offset to the left side of the fence....

 

[Stick486]

Personally I would make that cut at the table saw. It doesn't look like your router table has a split fence, so you might be able to cut some scrap, and place it on the out feed side to support the cut. But really the safest is the table saw.

agreed...

 

[Stick486]

You need a featherboard to push the piece into the fence. I'd suggest having one before the bit, and one after. Need not be at an angle on the one after the bit so long as it's pressed against the bit.

that's not gonna work brcause of the offset..

 

[Stick486]

Another way to do it is to move the fence back to the width of the piece you are machining, you then turn the piece around and feed the piece in from the left side of the table to prevent the bit from pulling the timber along with it, the timber goes between the fence and the router bit, use feather boards to keep the piece against the fence. Make sure you use push sticks and/or push pads when doing this.

This is what I do when I want a piece dressed on the edge of a certain width, cut it a mm or two wider on the table saw then take the excess off on the router table.

for the inexperienced this is a can of DANGEROUS you are suggesting the OP to open...
not a good plan...
what works for you may send somebuddy else to the ER...

 

[Terry Q]

Any time you are profiling an edge with out a bearing, you need to offset the outfeed fence forward by the amount of wood you are removing with the bit. What you are doing is sniping your board just as if you were using a jointer with the outfeed table set too low.

If you have a face that can be removed you can shim it out the depth of cut.

An Incra LS Positioner with a Wonder Fence is designed with accurately adjustable offset fences for those not familiar with Incra products.


In woodworking there is always more then one way to accomplish something.

 

[DesertRatTom]

that's not gonna work brcause of the offset..

It's a camfer cut, so some of the workpiece is going to remain supported by and against the fence. The bit would be buried in a split fence with only a small portion of the bit exposed. My eyes are not perfect anymore, but it looks like a split fence to me.

 

[tomp913]

Am I missing something here - why can't the fence and bit be adjusted so that the bit intersects the plane of the fence at the height of the thickness of the piece of wood? To put it another way - stack two pieces of wood of the correct thickness on top of each other, overhanging the top one towards the fence and then raise the cutter/move the fence until the corner of the wood hits the intersection between the angle of the bit and the face of the fence. You'll still chamfer the wood to a sharp point, but the sharp point will contact the fence past the bit and prevent movement. Infinity Tools has a little video

The video shows adjusting the fence flush with the bearing, but not setting the height. He does show sticking a second piece on top using double-sided tape to protect the fragile edge which is a good idea.

 

[Stick486]

It's a camfer cut, so some of the workpiece is going to remain supported by and against the fence. The bit would be buried in a split fence with only a small portion of the bit exposed. My eyes are not perfect anymore, but it looks like a split fence to me.

looks like it's not a split fence but it has a left and right sacrificial...

 

[Hypnotoad]

for the inexperienced this is a can of DANGEROUS you are suggesting the OP to open...
not a good plan...
what works for you may send somebuddy else to the ER...

You are right, if done properly it works fine but someone else may not use proper safety precautions. Thanks for the advice.

 

[Stokestack]

Thanks, guys. I have a featherboard on the fence already. I can't mount one on the table because the board is wider than the maximum bit-to-featherboard distance this table allows.

Also, I do have a split fence, but the width of the material I'm cutting away was determined somewhat on the fly so I don't have a shim of exactly the right thickness. Do some fences allow precise adjustment of one half forward to support workpieces in situations like this? Seems like a pretty basic feature.

The double-sided tape solution is one I've used for other routing and cutting in the past. In this case, it's a pain in the ass because this is a five-foot piece of thin cedar that flexes a lot. I'm using it as a threshold of sorts between some tile and a concrete floor that is a bit lower than the tile; the board will abut the tiles and slope down to the concrete.

In the end I just chamfered more than enough board, so I can cut off the crappy ends and have sufficiently decent material to cover the area I need.

 

[mgmine]

As Tom said use feather boards. But put one before the bit to keep the part being cut tight to the fence, better yet put two before the bit. Put the one on top directly over the bit.

 

[roxanne562001]

Thanks, guys. I have a featherboard on the fence already. I can't mount one on the table because the board is wider than the maximum bit-to-featherboard distance this table allows.

Also, I do have a split fence, but the width of the material I'm cutting away was determined somewhat on the fly so I don't have a shim of exactly the right thickness. Do some fences allow precise adjustment of one half forward to support workpieces in situations like this? Seems like a pretty basic feature.

The double-sided tape solution is one I've used for other routing and cutting in the past. In this case, it's a pain in the ass because this is a five-foot piece of thin cedar that flexes a lot. I'm using it as a threshold of sorts between some tile and a concrete floor that is a bit lower than the tile; the board will abut the tiles and slope down to the concrete.

In the end I just chamfered more than enough board, so I can cut off the crappy ends and have sufficiently decent material to cover the area I need.

I always make my own fences out of wood / scrap board for what ever project I am working on. The fence doesn't have to be fancy just functional. see attached rough sketch. I just bore a clearance hole in the center then cut them on the table saw If you want to make an adjustable split fence it should be pretty easy. Bill Hylton's book Router Magic has a good section on building a split fence. You could just expand on it and install adjusting screws on the out feed.
I would think if you made a split fence and used adjusting bolts instead of shims on the out feed fence that it would work for you.

 

[OBG65]

From your picture it looks like you are taking a full thickness cut which if the same as jointing the edge but you are using a chamfer bit. If so, just like others have said you need to offset the outfeed side of the fence, One easy way is to put a piece of laminate the height of of your fence on the outfeed side. This will offset the outfeed side by ~.002-.003. Then place a straight edge against the fence and move the fence so that the straight edge is touching the cutting edge of the bit. Take light passes until you get what you want.

BTW, by the looks of it, what you are showing can also be interpreted as a bevel cut which is best on on a table saw.

If what you want to do is place a chamfer edge on the top of your board (which will be the side riding on the router table top), then lower the bit to the height of the profile you want and run the board against the fence. Since you are only cutting a small portion of the board, the offset is not necessary since the majority of it will still be riding up against the fence. It's the same thing if you were going to round over an edge on the router table.

 

[harrysin]

Stick in post 7 is the easy way. This shot of an old demo. shows the principle.