Using the OF 1400 to route at a 15 degree angle

[Grits]

I am building a Moravian workbench and everything is pretty simple in the build except for the 15 degree leg mortises that are giving me a spot of trouble. I’ve watched the accompanying DVD and Will Myers masterfully chops it out by hand through the 4 inches but I’m definitely not at the level where I feel like I could do that by hand. I currently live in an apartment and I don’t have access to a drill press and figured I may be able to rig something up to route it out (a shim or ramp for the router perhaps). Can anyone suggest a jig of some sort to route out angles in a handheld router? Attached is a picture for clarity.

 

[Crazyraceguy]

4 inches of depth is going to make this quite a challenge. Even ignoring the angled aspect, which is tough enough, you are not likely to find a way to plunge that deep from one side. A whole lot of very careful marking and transferring is going to be needed. then you are going to have to come at it from both sides, meeting in the middle.
Then, you throw the angle into the mix, complicating it infinitely more. 15 degrees is not so extreme as to eat up all of your depth of cut, so some kind of wedge/jig could be fabricated, but honestly, it would probably be easier to do this with hand tools. A hand held drill, forstner bit, and a chisel should do it.
The beauty  of this kind of thing is that you never see the inside of it, once assembled. So it only has to be "pretty" at the shoulder and the open end,

 

[Grits]

Thanks for the reply. If I couldn’t figure out how to route it I had a backup plan of using a drill guide bushing set into an angled block of wood to make a guide. This does sound much more simple after your comment haha.

 

[ChuckM]

Snip. Attached is a picture for clarity.

What you need is some kind of a mortising jig which can be simple for one-time use, or something quite sophisticated like this:
[attachimg=1]

The idea is that you angle the workpieces not the router to mill the mortises:
[attachimg=2]

After you rout the first side, rout the other side KEEPING the same reference face towards the jig, if the bit is not enough to bore through the workpiece from one side. If even after routing from both sides the mortise, there is still material left in the middle, any bench chisel can take care of that.

P.S. Spiral bits rather than straight bits are better suited for this kind of milling, esp. the upspiral kind. E.g.https://www.leevalley.com/en-ca/sho...MI6rfz5cmW_gIVnzWtBh346gXSEAQYBCABEgJdN_D_BwE

 

[rmhinden]

Not the answer you are looking for, but suggest you reconsider getting a few mortise chisels and doing it by hand.  I don't think it would be that hard.

As [member=58857]Crazyraceguy[/member] said, it's going to be hard to cut a 4" mortise with a router. 

Suggest you do a few practice cuts to get the hang of it before doing the final mortises.

Bob

 

[ChuckM]

Snip.

Suggest you do a few practice cuts to get the hang of it before doing the final mortises.

Bob

Unless the OP has been a hand-tool user for some time or is a born traditional woodworker, my bet is that his practice cuts (good advice by the way, as it is always prudent to use scraps to learn a new skill or technique) would convince him that cutting clean mortises by hand is a lot more than just chopping down. Somewhere I saw an aid that Derek Cohen came up with for mortising. That would help.

 

[Grits]

I appreciate the replies and especially Chuck's drawings. My new plan is to rough it out with a drill bit and bushing and then refine it using Paul Seller's chisel guide technique and then using the 75 degree offcut from cutting the tenon as a chisel guide clamped along the width.

Paul Seller's chisel guide technique here

 

[derekcohen]

I am building a Moravian workbench and everything is pretty simple in the build except for the 15 degree leg mortises that are giving me a spot of trouble. I’ve watched the accompanying DVD and Will Myers masterfully chops it out by hand through the 4 inches but I’m definitely not at the level where I feel like I could do that by hand. I currently live in an apartment and I don’t have access to a drill press and figured I may be able to rig something up to route it out (a shim or ramp for the router perhaps). Can anyone suggest a jig of some sort to route out angles in a handheld router? Attached is a picture for clarity.

Hi Grits

The key here is accurate marking out. Below is a drawing of the mortice ...

The green area will be routed out, half from each side. The pink area will be chopped out with a chisel - don't worry. This will be straight forward.

I have designed a fixture for guiding a chisel for morticing. It is based on the one made by Paul Sellers, but (obviously) better

There are two issues with Sellers' guide. Firstly, he holds his work in a vice, which is a no-no as the work piece will slip down. You can see this in his videos, and that he frequently has to make adjustments. Secondly, he has made a fixed position guide, and wants to sell his, which means you need a half-dozen of these (terribly simple) pieces for the desired offset.

The guide I designed has a variable position fence, and the work piece is placed on the bench top.

The fence also acts as a hold down, preventing the work piece to be lifted by the mortice chisel.

From the rear ...

The fixture is simply a long fence with a fine sandpaper as non-slip, against which the stretcher is clamped, and a short sliding fence, which will act as the depth control.

A marked mortice (yours will be marked in three sections, as above) ..

Place the stretcher on the bench and drop the fixture on top of it. Clamp the fixture in the bench …

Now adjust the sliding fence alongside the registration side of the mortice …

Clamp the stretcher against the long fence and begin chopping with the chisel against the sliding fence ..

The aim here is to achieve perpendicular sidewalls.

If all this is too difficult - hopefully it is not - then the other way to make the mortice is to laminate three boards together, with the mortice section as the centre board (in two sections) and fitted around the stretcher. Easier but more work and not as much fun

Regards from Perth

Derek

 

[Crazyraceguy]

The aim here is to achieve perpendicular sidewalls.

If all this is too difficult - hopefully it is not - then the other way to make the mortice is to laminate three boards together, with the mortice section as the centre board (in two sections) and fitted around the stretcher. Easier but more work and not as much fun

Regards from Perth

Derek

I nearly suggested that, but thought it went against the idea of figuring it out, rather than just getting the job done?
I would probably do it in a modified "half way between" version. Instead of 3 layers, I would cut the mortice as somewhat of a half lap, in a board 2/3rds of the total thickness. A router and jig would make them very consistent, but if you had access to a radial arm saw, it would be quicker. Even an angled fence on a tablesaw sled could do the same, but upsidedown.
Then cover it up with the other third. That skips the alignment issues of three layers.

 

[Mortiser]

I'm doing a very similar thing now on a Japanese style sitting bench with wedged, mortise and tenon joints. The single, long lower stretcher runs into the two lower, shorter stretchers that run between the front and back legs; legs and joints all at compound 4 degree angles. As Derek says, accurate marking out is the key. Cut your tenons, then mark the tenon placement on the legs, resting your stretchers on spacer blocks at each end, legs and blocks sitting on your bench.  Mark your mortises appropriately on opposing sides. Drill the waste with a smaller diameter bit than your mortises, 1/2 way down from each side, angling your drill according to your angled, layout lines. Use your chisel to start chopping your mortises going halfway down from each side, removing the waste on each side from the middle toward your mortise layout marks. After you've removed most of the waste, pare the sides halfway down to connect the outer edges of your mortises. Your angles will then be correct. Test fit to fine tune. Pencil lead helps here.
I think I can complete this kind work faster by hand than the time for thought and building jigs and trial and error. And I have a shop full of tools. Besides, it's just enjoyable work.

Good luck with your project.

 

[Michael Kellough]

I'm doing a very similar thing now on a Japanese style sitting bench with wedged, mortise and tenon joints. The single, long lower stretcher runs into the two lower, shorter stretchers that run between the front and back legs; legs and joints all at compound 4 degree angles. As Derek says, accurate marking out is the key. Cut your tenons, then mark the tenon placement on the legs, resting your stretchers on spacer blocks at each end, legs and blocks sitting on your bench.  Mark your mortises appropriately on opposing sides. Drill the waste with a smaller diameter bit than your mortises, 1/2 way down from each side, angling your drill according to your angled, layout lines. Use your chisel to start chopping your mortises going halfway down from each side, removing the waste on each side from the middle toward your mortise layout marks. After you've removed most of the waste, pare the sides halfway down to connect the outer edges of your mortises. Your angles will then be correct. Test fit to fine tune. Pencil lead helps here.
I think I can complete this kind work faster by hand than the time for thought and building jigs and trial and error. And I have a shop full of tools. Besides, it's just enjoyable work.

Good luck with your project.

Yeah but, your name is Mortiser… [wink]

 

[ChuckM]

When I do M&T joinery by hand, I'm in Tage Frid camp and always start with the mortises and cut the tenons to fit, though some, such as Ian Kirby, prefer the opposite.

 

[Mortiser]

Yeah but, your name is Mortiser… [wink]

[big grin]  I like it!

 

[Grits]

[member=4358]derekcohen[/member] Thank you for the advice. I am a huge fan of your site and it is one of the reasons I have decided to pursue more hand tool woodworking. I've been hoping you would write up a tool review of the Gramercy Sash Saw because I am in the market for a tenon/sash saw as I have a carcass and dovetail already. Is the Gramercy one that you would recommend or are there others you would suggest?

Cheers