Technique for Dado that doesn't extend through either side

[DavidCBaker]

I'm making a small jewelry box. I need to put a dado around the bottom of the sides, but the sides are joined with through dovetails, and so the dado can't extend all the way to each end. It must stop just before the ends on both sides of the board. I have a router in a table and several free standing routers, and I'm assuming that I'll use one of the latter, but I'm having trouble envisioning how I'll do this.

I could use one of the adapters that slides along along a guide rail and use the plunge feature on the router, but how do I get the dado to stop at the perfect spot? Is there a "stop" that can be attached to the guide rail?

I just know that one of you has the answer and I'm going to feel stupid once you say it, but I'll just take that risk.

 

[Roachmill]

Part number 491582 (https://www.festool.co.uk/accessory/491582---fs-rsp) is a rail stop (or "Kickback stop" as Festool call them). A pair of them are very handy indeed... so long as you don't lose one or both of them

 

[DavidCBaker]

Part number 491582 (https://www.festool.co.uk/accessory/491582---fs-rsp) is a rail stop (or "Kickback stop" as Festool call them). A pair of them are very handy indeed... so long as you don't lose one or both of them

Thanks! I think that allows me to attach the router to the rail and keep the cut straight, but that doesn't fix the issue of where to stop the cut short of the edge, right? I might be missing something, here. I do that that part and it's what I was intending to use, but I'm looking for the solution that keeps the dado from extending all the way to the edge of the board on both sides. I guess tape on the rail, but that feels inaccurate and inelegant.

 

[nclemmons]

If you have a router table, it’s easy to do stopped dados. 

I use painters tape to indicate a location on the fence to both start and stop a dado I dont want to see.  The tape is offset from the bit such that you leave an amount on each end where your dado is going.  You hold your wood against the fence at the line and plunge it down on the running bit and move the piece forward till the end matches the second piece of tape.  Fast, easy, and safe way to do them.

 

[RKA]

You should be able to sight it with a plunge router, however, if you want it to be more precise, stop short of the end points and finish with a chisel.  Use a combination square as a reference edge for the bac of the chisel.  Metric chisels work well because they are usually slightly undersized compared to standard imperial dimensioned bits.

 

[DavidCBaker]

If you have a router table, it’s easy to do stopped dados. 

I use painters tape to indicate a location on the fence to both start and stop a dado I don’t want to see.  The tape is offset from the bit such that you leave an amount on each end where your dado is going.  You hold your wood against the fence at the line and plunge it down on the running bit and move the piece forward till the end matches the second piece of tape.  Fast, easy, and safe way to do them.

Ah, thanks. That occurred to me, but I wasn't sure if that was safe or not. Since the wood is only 1/2" thick, that makes sense. Maybe I'll try that (with a scrap piece)!

 

[DavidCBaker]

You should be able to sight it with a plunge router, however, if you want it to be more precise, stop short of the end points and finish with a chisel.  Use a combination square as a reference edge for the bac of the chisel.  Metric chisels work well because they are usually slightly undersized compared to standard imperial dimensioned bits.

Another good idea. Thanks. I have some good chisels, but I'll need a narrower one. Good thinking.

 

[Roachmill]

It sounds like precision is key here so physical stops (these can be set on a router table but on a rail you can easily see where the bit is going to go) will let you tweak the cut to your heart's content. Set them up so you know you're starting and stopping well within where you want the dado to go. Then measure from the outermost edge of your cut to where you'd like it to start/stop and adjust the rail stop that much in the desired direction. As others have said, best to leave a couple of mm either end to square up with chisels.

 

[peter halle]

Part number 491582 (https://www.festool.co.uk/accessory/491582---fs-rsp) is a rail stop (or "Kickback stop" as Festool call them). A pair of them are very handy indeed... so long as you don't lose one or both of them

Thanks! I think that allows me to attach the router to the rail and keep the cut straight, but that doesn't fix the issue of where to stop the cut short of the edge, right? I might be missing something, here. I do that that part and it's what I was intending to use, but I'm looking for the solution that keeps the dado from extending all the way to the edge of the board on both sides. I guess tape on the rail, but that feels inaccurate and inelegant.

Those limit stops are designed to a. Reduce the risk of kickback if plunging a saw in the middle of a work piece, and b. To limit travel on the guiderail.  If you have a Festool router the base is inscribed with a line on all four sides that indicate the center of the bit.  So if you are needing to stop at a certain point you would mark a line inwards of the stopping point 1/2 of the diameter of your bit.  Align the router scribe line to that point and then slide the limit stop on the rail up to the router and tighten down.  The outrigger foot also helps with alignment whereas it has the markings and a scale on it.

Hope this makes sense.  I had done a thread on this years ago but the images are gone now.

Peter

 

[DavidCBaker]

Thank you, Peter. Yes, that helps. Starting at the end of the line by plunging there...moving inward...and then repeating from the other starting point will make it exact. Thanks much!

 

[semenza]

I take it that these are decorative exterior dadoes?

I would use a router table if possible with tape or marks for the ends but stops on the fence will be better.

Seth

 

[DavidCBaker]

I take it that these are decorative exterior dadoes?

I would use a router table if possible with tape or marks for the ends but stops on the fence will be better.

Seth

No, these would be interior--the bottom shelf of the jewelry box would fit inside them.

 

[Michael Kellough]

Use the router table and do it the same as you would with mitered joints, except set physical stops on the fence to prevent overshooting.

I’d lower the board into the spinning bit a half inch shy of the end of the cut then go to the end (either) and reverse. Be careful to reverse feed direction at the end of the run very quickly to avoid burning. It happens fast when the bit is in contact with wood covering 50% of it’s diameter.

 

[Stone Message]

I agree with Michael, use the router table as it is much easier for precise control of cuts like these.

I do not use physical stops but put a pencil mark where the piece of wood must start and stop. I sometimes use a strip of masking tape to write on instead of putting a mark on the aluminium fence or table.

I show this type of technique from about the 4 minute point in this video:


Peter

 

[DavidCBaker]

Thanks, Michael and Peter!

 

[justard]

I agree with Michael, use the router table as it is much easier for precise control of cuts like these.

I do not use physical stops but put a pencil mark where the piece of wood must start and stop. I sometimes use a strip of masking tape to write on instead of putting a mark on the aluminium fence or table.

I show this type of technique from about the 4 minute point in this video:

Peter

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