How do I cut a rebate following a curved edge on a router table?

[machone]

I have tried pushing the wood against the fence at the required distance from the cutter but a constant distance from the curved edge is difficult to keep by hand resulting in a ‘wobbly’ trench....it also turned the router table into a formidable weapon! Thankfully it was just a practice piece, but what is the best way to do this please?

The trench needs to be about 10mm from the curved edge of the stock which is a plain curve, not compound.

 

[Spectric]

Hi

You need a bearing guided cutter, use a starting pin with no fence.

 

[Spectric]

Just realised the rebate is set back 10mm, so guide bush and a template.

 

[Yojevol]

Yes, I know the problem and when I've encountered it I've been able to live with the wobbly result. The answer could be to not use your curved edge as the reference but to make a curved pattern and use the router in its basic mode, ie, handheld. Use a bearing follower and a straight cutter. The problem may be how to hold the pattern in place without restricting the router.
Brian

 

[machone]

Bearing follower and template seems to be the answer as I don’t really want to buy any extra equipment. The ‘trench‘ edge is as visible as the top edge(hatch opening surround) so needs to be smooth. Looks like a router no table job. Thanks for the replies. Might try an edge cutter if I can get it deep enough.

 

[OrangeFive]

Cut the curve on your timber then get a rebate cutter for a hand held router and let the bearing follow the curve. I find this the easiest method anyway but the cutters aren’t cheap. Trend 46/390X1/2TC Guided large rebater - 1/2" Shank | CNS Power Tools Ltd

 

[Derek Cohen (Perth Oz)]

Do this either freehand (work piece must be secured), or with a router table without the fence (freehand the work piece into the router cutter) using a pin to guide.

Rebate cutter, with a series of bearing sizes ...

Use a larger diameter to begin, then decrease in size until you reach the rebate depth you want. This will enable you to control the cut.

Regards from Perth

Derek

 

[MusicMan]

Yes, I know the problem and when I've encountered it I've been able to live with the wobbly result. The answer could be to not use your curved edge as the reference but to make a curved pattern and use the router in its basic mode, ie, handheld. Use a bearing follower and a straight cutter. The problem may be how to hold the pattern in place without restricting the router.
Brian

Double sided sticky, best quality from Tesa. I've used this for holding patterns for routing and even for machining Tufnol on a milling machine (acknowledgement and thanks to Custard).

 

[Ollie78]

Double sided sticky, best quality from Tesa. I've used this for holding patterns for routing and even for machining Tufnol on a milling machine (acknowledgement and thanks to Custard).

If you Don't have double sided tape use the "super glue trick" . Put masking tape on each side to be fixed then super glue them together. Once done just peel of the tape. I use this on my cnc machine all the time, it is remarkably strong.

Another way to do a rebate on a curved edge is to use a sub fence on the router with 2 pins. These can be made from dowels. So you put a sub base on the router and drill the first dowel in, adjust the cutter to where you want it to be, Mark and fix the second dowel. Now the router will stay evenly spaced around the curve.
Hope that makes sense

Ollie

 

[Distinterior]

Have I misunderstood what the OP is trying to do...????....

The way I read it is,.....He is trying to rout a curved channel (he used the word"Trench") that is set 10mm back from the edge of a curved board....although he has used the word rebate in the thread title, its not a Rebate.
The cutters all linked to above are indeed Rebate cutters but wont work!!!

Or, am I wrong????

 

[Hornbeam]

If the circle is a reasonable size you could make a circle cutting attachment to fit onto the fence bars of your router. or a false base and jig. If you spend a bit of time you have a jig that you can use for all circle diameters. See a couple of images on attached
https://www.google.com/search?q=cir...UEolwKHSl8BhwQ_AUoAXoECBUQAw&biw=1680&bih=907

 

[Peri]

I posted this earlier in the thread, then changed my mind.

I know it's not for a table, but my bosch handheld router came with something like this. I've never used it, but from what i remember (and I bought the router over 20 years ago, so I might be wrong), it mounts to a slot in the faceplate, and the rubber wheel rides along the edge of the job, allowing you to route a channel a set distance from that edge.

Maybe there's something similar for the table - or hopefully might give you an idea

 

[HamsterJam]

Attach two rounded blocks to the fence to your router table or use two pins one either side of the cutter Then set the distance accordingly. There should be no wobble as long as both blocks/pins stay in contact with the edge of the workpiece. This will need some thought at the start and end of the cut.
Alternately, you could try and cut a curved sub fence to follow the curve on the workpiece but friction might mean it is hard to move the workpiece past the cutter.

 

[HamsterJam]

I posted this earlier in the thread, then changed my mind.

I know it's not for a table, but my bosch handheld router came with something like this. I've never used it, but from what i remember (and I bought the router over 20 years ago, so I might be wrong), it mounts to a slot in the faceplate, and the rubber wheel rides along the edge of the job, allowing you to route a channel a set distance from that edge.

Maybe there's something similar for the table - or hopefully might give you an idea

View attachment 93949

I have something similar and have used it to shape curved edges with a non-bearing cutter. I think something similar could be used handheld to produce a trench a set distance from a curved edge although I think two points of contact are required to eliminate wobble.

 

[Doug71]

Add a sub fence same curve as workpiece, I do this on my spindle moulder sometimes.

 

[machone]

Disinterior is correct, I am not really trying to cut a rebate, sorry, newbie with the terms, I am trying to cut a channel offset from the curved edge. I have done it with a piece of pine on my router table but not satisfied with the results - the channel or inside edge as it will become, is not parallel with the outside edge curve. The inside edge will sit ontop of steel at the same curve so lumps and bumps might be covered up a bit with mastic but I will know they are there!

I think the Bosch attachment would work I have seen router attachments as posted above but cannot find one for my dewalt. The attachments I have offset the cutter from the edge too far.

I was hoping for an idea with the table I hadn’t thought about and so far the template with double sided stick and a follow bit looks favourite. I will try an offset cutter I have on a test piece but it is thin and I think will cause breakout over the curve. The circle is too large to try the circle cut...I tried with a piece of string across the room which was not long enough. Have also tried a block of wood between the router follower and the piece to increase spacing but the results were worse than with the table.
I am sure with lots of practice I could hand/pin/fence cut on the table but I am not that good yet. The force generated when the piece was mid cut between the fence and the cutter loosened the router from the table.

 

[machone]

Add a sub fence same curve as workpiece, I do this on my spindle moulder sometimes.

View attachment 93951

This will do it I think, thanks!

 

[Distinterior]

What is the Radius of the curve you are trying to cut?
How wide & deep is the "Trench"?
What is the approximate size of the piece of material you are working with?

EDIT. Doug has suggested what I was going to suggest

 

[machone]

Add a sub fence same curve as workpiece, I do this on my spindle moulder sometimes.

View attachment 93951

Tried it, worked well, first time, with double sided sticky on the sub fence, which I used the bandsaw offcut of the original piece. Happy with the result, thanks!

 

[Terry - Somerset]

The sub-fence will work well providing the curve is a constant radius.

Otherwise the workpiece will simply default to two points of contact which would leave the "trench" a variable distance from the edge. This is true of any solution which relies upon wo points of contact.

Only solution which will fit all curves (or a curve followed by a staight section) would be a template and bearing guided cutter (I think)