Thread: SB's new mortise jig

Well guys I didn't think you would let me off so lightly. I guess the pictures must of said it all.

SB

It is great to see another jig appearing on the forum and I am sure some will copy and maybe modify what has been presented to suit their needs. Some of us are woodworkers for as long as 55 years, woodworking all our working life and if I were to offer any criticism (constructive of course) it would be "avoid using metal round a router". But on the other hand others have a great experience with metal would maybe disagree. What is important is when it is finished does it do the job?. My first attempt at using the 'Ski mode' was made of metal, that was when I was just getting into template/Jig making some 25 years ago.

What is important is we are making an attempt at Jig making to improve our routing skills.

My simple mortice jig was made specifically for the material I was using at the time and I would have constructed a number of the same jig with a different variation to suit material I was working on.
Tom

Originally Posted by Template Tom

It is great to see another jig appearing on the forum and I am sure some will copy and maybe modify what has been presented to suit their needs. Some of us are woodworkers for as long as 55 years, woodworking all our working life and if I were to offer any criticism (constructive of course) it would be "avoid using metal round a router". But on the other hand others have a great experience with metal would maybe disagree. What is important is when it is finished does it do the job?. My first attempt at using the 'Ski mode' was made of metal, that was when I was just getting into template/Jig making some 25 years ago.

What is important is we are making an attempt at Jig making to improve our routing skills.

My simple mortice jig was made specifically for the material I was using at the time and I would have constructed a number of the same jig with a different variation to suit material I was working on.
Tom

Thanks Tom, I know mine will not do the rounded back of a chair as yours might or others and its only just occured to me that this is one of the drawbacks of my jig.

SB

Originally Posted by Superbunny

Thanks Tom, I know mine will not do the rounded back of a chair as yours might or others and its only just occured to me that this is one of the drawbacks of my jig.

SB

I have never made a Jig that will be able to do all I want to that is the reason I have a shed full of jigs and templates because I make a new on to complete the process I am working on at the time. You will also do what I have done over the years. All my templates and jigs are constructed in my workshop at very little expense. I remember someone saying they get more satisfaction in producing the jig than they do using it. I suppose I am like that when I have a problem I do not give up until I have made the Jig and templates.

The difference might be I make my jigs and templates with the template guides as the main accessory to producing the shapes or the joints such as sliding dovetails on a three legged wine table, or the tenon on the end of a mitre when I was adding the rails to a project which were at 45degrees to the leg, or even a sliding dovetail on the mitre.

SB,

I am afraid it is not clear to me how your jig works. If it only takes a couple of hours to build, it sounds as though it is a worthwhile one to make. Could you explain just what it does and how it does it? I could not work it out from your pictures without any further explanation.

Rocker

Originally Posted by Rocker

SB,

I am afraid it is not clear to me how your jig works. If it only takes a couple of hours to build, it sounds as though it is a worthwhile one to make. Could you explain just what it does and how it does it? I could not work it out from your pictures without any further explanation.

Rocker

Rocker,

You know you can come around and see it if you want.

Basically you loosen the bearing guides. place the jig on your router via two holes in the base plate (Pic 5) (the triton router comes with these). Mark the centre line of the mortise and the start and finish of the mortise. Place the timber mortise face down on a table and place the two bearing guide rails bearing guide down on either side of the timber to be mortised then clamp.

Turn the timber and bearing rails the right side up and you are left with a smooth plane top side up to place the jig and router on with the bearings slotted into the bearing guide rails (Pic 2 & 10). Move the jig and router untill the jig is lined up with the mortise centre line (Pic 8) then tighten up the bearings either side. Turn the jig and router 180 degrees and do the same. Check the certre line on the jig runs with the centre line of the mortise as you push the jig over the centre line. Plunge you router until about 1-2 mm from the timber and lock. Move the router bit to the start of the mortise and then put a clamp on the timber as a stop. Do the same for the finish stop (Pic 3). Make sure you have turned the router bit perpendicular to the start line so the blade is at its maximum cut.

Now you are ready to start cutting the mortise. If the timber is not the same depth as the bearing guide rails you can clamp the lot in a vise to hold it better so it doesn't move away from the jig and router bit.

I would make a couple of proper stops to use insted of clamps later.

SB

SB,

Thanks. I am beginning to grasp the concept of how your jig works, but I am still not quite clear how you ensure that the bearings are positioned so that the router runs parallel to the face of the workpiece. One of your photos shows a square being used, which is presumably part of this process. It seems to me that the four bolts which attach the bevel blades, as well as the bolts of the bearings, must be part of the equation.

I am also unclear about the function of the two strips of wood between the curtain rail holders shown in photo 4.

The relative simplicity of making your jig makes it an attractive alternative compared to mine. However, mine is more versatile, in that it can be used for mortices in curved rails, as well as for routing hinge mortices on boxes. Mine also has the convenience of micro-adjustability by means of its threaded-rod fence adjustment system. But it does take about a day's work to build, so for woodworkers who do not envisage needing to cut more than a couple of dozen mortices, it is not worthwhile.

Rocker

Hello Rocker,

I like your plans -- the work looks challenging but the plans themselves seem very clear. I've downloaded all I can. But I can't get the crosscut sled plans to download. Any ideas?

- Michael

Sorry, all: I should've sent this query direct to Rocker as a PM. If anyone else is interested in his response, say so, and no doubt he will respond here too.

- Michael

Originally Posted by ToothFairy

Hello Rocker,

I like your plans -- the work looks challenging but the plans themselves seem very clear. I've downloaded all I can. But I can't get the crosscut sled plans to download. Any ideas?

- Michael

Michael,

Dunno what the problem is; I can download the crosscut sled plans OK.

Rocker

Originally Posted by Rocker

SB,

Thanks. I am beginning to grasp the concept of how your jig works, but I am still not quite clear how you ensure that the bearings are positioned so that the router runs parallel to the face of the workpiece. One of your photos shows a square being used, which is presumably part of this process. It seems to me that the four bolts which attach the bevel blades, as well as the bolts of the bearings, must be part of the equation.

I am also unclear about the function of the two strips of wood between the curtain rail holders shown in photo 4.

The relative simplicity of making your jig makes it an attractive alternative compared to mine. However, mine is more versatile, in that it can be used for mortices in curved rails, as well as for routing hinge mortices on boxes. Mine also has the convenience of micro-adjustability by means of its threaded-rod fence adjustment system. But it does take about a day's work to build, so for woodworkers who do not envisage needing to cut more than a couple of dozen mortices, it is not worthwhile.

Rocker

Rocker

As the outer runners are clamped parallel with the workpiece and the runner trench widths are cut exactly the width of the bearings, the jig has no option but to run parallel with the work piece. This also sets the distance of the bearings and controls the jig as it is moved over the workpiece when cutting the mortise. The bearing guides the whole jig in its movement over the workpiece back and forth. As the runner trench is exactly the width of the bearing, the bearing has no option but to follow the trench and is constrained by it in the process. The set square was just a check that the front and back bearings are parallel with each other after I made the jig. The pictures represent the jig as being made and used for the very first time. The two bits of wood help give the jig regidity and a nice face to run over the workpiece. Without the wood bits I found that the jig could go out of square easily when setting up for a cut. In addition, it gives the jig a greater serface area for the jig and router to rest on. The bevels are simply a chep way to join the two ends together and for them to be exactly the same spacing apart. Yes, I agree that your jig has some advantages over mine but for the work I do it is very effective, efficient and cheap. I'm in no way running down your jig as I think it is one of the better ones arround. I just thought that for many woodworkers my jig is sufficient. I'm very happy with how it has turned out and its simplicity to make, set up and use.

SB

SB,

I think your jig is very ingenious, and is obviously very easy to build, so long as the requisite hardware is available. It looks like the best choice for those people who only envisage wanting to rout a relatively small number of mortices.

Rocker

Originally Posted by Rocker

Michael,

Dunno what the problem is; I can download the crosscut sled plans OK.

Rocker

Thanks, Rocker -- wouldn't work with Firefox, but I downloaded it OK with IE. Usually it's the other way 'round . . .

- Michael