Lock Miter Users - A Setup Jig a Must Have?

[Patrick Irish]

I scored a new Frued Baby Lock Miter (for 3/8-3/4 thick material) on ebay for half off retail.

From my research, setup can be a pain. Rockler sells a phenolic jig but it's only for 3/4" thick material.

Infinity Tools has one for this size bit for $30 and a kit for $50'ish for the larger lock miter bit. Not sure I'll ever get that bit.

Just wondering if a jig for setup is a good idea or not a big deal.

Thanks.

[Bill Orbine]

It can be difficult at first but you'll learn and the process becomes easier. Set up on your own and make the setup jigs yourself for future use. This way you can have whatever thickness sample allowable by the tooling

[Doug Hepler]

Patrick,

Bill is technically correct, but the setup jig is a real convenience. I did a dozen or so lock miter joints setting up by eye. Then I found the instructions on the Lee Valley web site. They were very helpful. I got tired of test cuts and finally bought the Infinity setup jig. It helped a lot. So now I use the setup jig and the Lee Valley instructions and often get the router table set up with 2-3 tries. If your vision is sharper than mine (not a high bar) you may be able to get it in 1-2 test cuts.

The problem with making a setup jig from a previous setup is that the thickness of the stock has to be the same every time. This is not necessarily going to be true.

The main issue, after setup, is a carrier to feed the horizontal piece past the cutter. As you may already have noticed, the right end of the workpiece tends to dive into the cutter. You can prevent this by making a sled or jig that rides against the router fence above the height of the cutter. That's what I do. Or, cut the horizontal piece extra long and trim it to size, removing the bad end.354739

[Alan Schaffter]

I scored a new Frued Baby Lock Miter (for 3/8-3/4 thick material) on ebay for half off retail.

From my research, setup can be a pain. Rockler sells a phenolic jig but it's only for 3/4" thick material.

Infinity Tools has one for this size bit for $30 and a kit for $50'ish for the larger lock miter bit. Not sure I'll ever get that bit.

Just wondering if a jig for setup is a good idea or not a big deal.

Thanks.

Disclaimer- I invented the the Infinity Lock Miter Master.

I did it out of necessity when I was working on a project that involved lock miters and I found all the set-up jigs and guide blocks were the pits- they assume you will use a certain thickness of wood. Did you ever see a sheet of ply that was exactly 3/4" thick? It is kind of bass ackwards to have a jig dictate the size of your the material!!!! Also, I found the instructions provided with almost all lock miter bits were flawed at best and more often than not, wrong! Long story short- I developed the LMM and it works. It works with almost all lock miter bits regardless of manufacturer, size or profile (I haven't found one it doesn't work with yet), will allow you to easily make lock miters in any thickness stock, and contrary to claims by many bit manufacturers, will allow you to make lock miters where each piece is a different thickness (for use with lock miter drawer boxes or casework with faceframes thicker than the box sides, etc.). It also allows you to easily make other special lock miter joints- "offset lock miters" and "corner spline lock miters."

You can view a video and the downloadable manual on the the Infinity website. The reviews have been very good. Search on it.

[Van Huskey]

Over the years I have used various methods to set up lock miters and always got them to work BUT I tended to avoid them since the setup always took a fair amount of time and some trial and error, great joint but a PITA no matter what method I used.

Now I have Alan's/Infinity jig and it is the bees knees. It works, every time with every thickness, the key is the elegance of the solution it is like most strokes of brilliance in that once you see it the thing makes perfect sense and sparks the "why didn't I think of that". Yeah someone could poo poo the price BUT they likely would have never used one. If you want to simplify the use of a lock miter bit this is what you need to buy.

BTW no connection to Alan or Infinity, other than Alan being a member here, heck we have probably disagreed more than we agree... :(

[Andy Giddings]

+1 on the Infinity jig - makes it easy and is almost dead on with the first attempt. Best money I ever spent on a jig and it repaid the investment on its first use in my case. Of course once you've got it setup and if you always use the same thickness material (eg 12mm BB ply for drawers) then make a set up block and use that in future as its quicker IME. Also no connection with Infinity

[Mike Tekin]

Can the infinity jig work on all Lock Miter bits...I am looking at Infinity, Freud, Whiteside

[Mike Cutler]

Can the infinity jig work on all Lock Miter bits...I am looking at Infinity, Freud, Whiteside

Yes, as far as my limited experience has been with it. I have a large Whiteside and smaller Freud. I have both jigs. You can set one up without the jig(s), but they definitely make it faster. I haven't tried to set up a shaper lock miter bit with them yet, but definitely want to try it.

Alan
Well done on inventing the jig(s)!!
Will they work with a lock miter shaper cutter??

[Alan Schaffter]

Wow, thanks guys!

As to the question whether the LMM will work with all lock miter bits. Just about . . . I have not heard of a lock miter router bit it won't work with. It will definitely work with the Infinity, Freud, and Whiteside lock miter router bits. Lock miter shaper cutters are a different story. It works just fine with some, not as well with others. Believe it or not, the LMM does not work well with the Infinity lock miter shaper cutter.

You can always use the LMM to set bit height, but setting the fence is a bit more involved if the plane of the carbide cutter is a chord as opposed to a radius. Instead of a big discussion, just see the diagrams below:

A three wing shaper cutter where the carbide cutters are all radii. The LMM will work fine with this type:

http://www.ncwoodworker.net/pp/data/2580/medium/Shaper_New.jpg

Illustrations showing a cutter that is a chord:

http://www.ncwoodworker.net/pp/data/2580/medium/ShaperB-1.jpg

http://www.ncwoodworker.net/pp/data/2580/medium/ShaperB-2.jpg

As I said, if the cutter is a chord you can still use the LMM to set the bit height as you would normally, but you will need to sneak up on the fence position. That is pretty easy to do with a test board that is the same thickness as your good stock and a few short cuts with the board in the horizontal position. Use the LMM to set bit height and to roughly set the fence. Leave the fence a smidge too far back. Make a short, 1/2" long cut. You will be left with a gap. Carefully adjust the fence closer to the bit and extend the cut a little more. Do that until you no longer have a gap. It is still pretty simple.

http://www.ncwoodworker.net/pp/data/2580/medium/setting_fence.jpg

If you have any questions just post or PM me. I sometimes have insights that the manufacturer does not. I don't visit here as often as I used to but, will respond if needed when I get an email alert to a new post. I'm not an employee of a "woodworking tool manufacturer or vendor," who does woodworking on the side. I'm just a hobby woodworker who occasionally comes up with a good idea. I have been very lucky that two great companies decided to manufacture my ideas- Infinity (Lock Miter Master), INCRA (I-BOX).

[Brett Luna]

+(whatever) for the LMM. I can't add much to what's been said so at the risk of being redundant I'll just say that it works and works well. Wait. I don't think anyone has said "elegant" yet so I'll also say that it's an elegant solution.

[Grant Wilkinson]

I was lucky enough to use a friend's before he moved away. My loss. It worked very well, but as I don't use the bit often, the $100 price tag to get one to Canada is out of reach for me. The next time I'm in the US, it will be on my shopping list.