Installing Roubo-style planing stop to allow height adjustment

[Eric Rathhaus]

I'm in the process of installing a planing stop. Most of the installations I've seen install the stop into a floating tenon that is then driven into the mortice in the bench top. I'm wondering if the mortice is tapered to allow some height adjustment? To get the teeth off the surface of the bench top, do you have to remove the whole tenon or drive the tenon deeper to put the teeth below the bench top surface?

Eric

[Richard Verwoest]

Friction fit

[Luke Dupont]

The wooden tennon that you describe is itself a planing stop too. Often times people just use that without the metal hardware. I imagine you can flip it around if you didn't want to mark your work.

Note an important point: the mortise should be cut at an angle of 2 or 3 degrees tilting towards the workpiece. If it is not, you may have the tendency for the work to slide up and over it. Though I imagine this point is less important if you only ever use the stop in conjunction with metal teeth, it would suck if you ever wanted to just use a plain wooden stop and discovered this defect in a 90 degree mortise.

It is friction fit. I've made a lot of such stops and never had a problem with the friction fit even as the seasons change -- no idea why, but it just seems to work.

[Eric Rathhaus]

Well yes it is a friction fit but you can have a friction fit with a taper to provide increasing friction.

[Eric Rathhaus]

Thanks, Luke.

[chris carter]

The mortise is perfectly straight, vertical, and cut to fit the stop (the wooden part) very very snug. The stop should be considerably long and you knock it up with your mallet, and knock it down with your mallet, stopping where you want it. For the teeth, they should be installed in the wooden part of the stop so that they are pointed very very slightly up. This is not absolutely necessary, but generally you want to make sure that you won’t whack the back of the metal part with yoru plane. I actually beveled the very top of the teeth on mine so that in a worst case scenario I will skate over the thing rather than hit the teeth full on (never happened so far, so maybe it was too much paranoia). Once everything is together and fit perfectly, you can chop out a little recess for the teeth so the whole stop will sink just below the surface of the bench. Some people don’t bother with that, particularly if their bench is so large that they have plenty of release estate available to avoid the stop. Personally, mine goes below the surface of the bench.

I’ve never heard of a tapered mortise. I think that would defeat the adjustability of the height. I’ve never heard of the 2-3 degree tilt either, but it should work (although it would be really difficult to cut the mortise at that angle).

Main bench:
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Another bench:
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[Eric Rathhaus]

Thx, Chris!

[Luke Dupont]

I’ve never heard of a tapered mortise. I think that would defeat the adjustability of the height. I’ve never heard of the 2-3 degree tilt either, but it should work (although it would be really difficult to cut the mortise at that angle).


Nice examples.

The 2-3 degree tilt is important if you ever use just the wooden tenon, without the metal teeth, as a stop. A 90 degree wooden stop might be angled back ever so slightly, and might wear over time at the top, making a ramp that lets the wood pop out and over it. It's commonly used for square bench dogs and plain wooden stops without the metal teeth.

With metal teeth you won't have that problem, so maybe it doesn't matter in your or Eric's case.

That said, it's not difficult to cut such a mortise in my experience. It's pretty easy to eye a few degrees with a long chisel and a bevel set up as a reference. It's kind of like sharpening -- your hands and eye are quite good at seeing and feeling even the difference between a degree or two. But, the trick is to just mark the mortise on both faces and chop from both faces, and just square the walls and you're good. Kind of like drilling a straight hole by coming at it from two sides and having them meet in the middle.

I also agree that tapering the tenon wouldn't make much sense. Keep it and the mortise the same width throughout.

[chris carter]

The 2-3 degree tilt is important if you ever use just the wooden tenon, without the metal teeth,

Now I get it! Thanks for the explanation. That makes a lot of sense.

[Derek Cohen]

I'm in the process of installing a planing stop. Most of the installations I've seen install the stop into a floating tenon that is then driven into the mortice in the bench top. I'm wondering if the mortice is tapered to allow some height adjustment? To get the teeth off the surface of the bench top, do you have to remove the whole tenon or drive the tenon deeper to put the teeth below the bench top surface?

Eric

Eric, I chose not to add a Roubo-style stop to my Roubo-type bench. The reason was that I found planing into a smallish section limiting. It was simply just not as stable as my alternative, which is a board at the end of the bench. This may be adjusted for height. Importantly, it offers a long registration surface for planing wide panels (which you will struggle to do with the Roubo stop).

https://i.postimg.cc/2SSCkVhQ/End-stop1.jpg

The inside face is covered with cork-rubber, which makes good non-slip.

https://i.postimg.cc/4N5JRz74/End-stop2.jpg

I did make a toothed stop, which is bolted to a dog. I came up with this design before TFWW began marketing their version. Mine is a 1” wide section of unhardened O1 steel (you could use mild steel), with teeth filed in. The bolts lock into threaded inserts ..

https://i.postimg.cc/25x4t551/3a.jpg

https://i.postimg.cc/pLzQDCbY/4a.jpg

https://i.postimg.cc/TPxVQbT8/2a.jpg

This stop works best when used in conjunction with a Doe’s Foot …

https://i.postimg.cc/B6Y2qwHs/5a.jpg

https://i.postimg.cc/9MRnrZrT/6a.jpg

The other advantage of this system is that the dog is able to be placed anywhere along the edge of the bench. I even have one for the wagon end vise. This makes it possible to lock work pieces very securely between two facing threaded stops.


Regards from Perth

Derek