# Lock Miter work



## allbarknobite (Sep 15, 2011)

Just routed 4 boards 8 ft long for a continuous Lock Miter joint, after modifying my old RBI Hawkeye Router table. 

It took a lot more time to set up the router than it did to rout the boards.

If there are any lock miter buffs out there, I would enjoy hearing from you.


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## derek willis (Jan 21, 2009)

allbarknobite said:


> Just routed 4 boards 8 ft long for a continuous Lock Miter joint, after modifying my old RBI Hawkeye Router table.
> 
> It took a lot more time to set up the router than it did to rout the boards.
> 
> If there are any lock miter buffs out there, I would enjoy hearing from you.


Mark,
Why are you locking such long boards, just curious.
I used to use this bit extensively for the joining of cabinet sides together with no visible joint at all and have always been very pleased with the result, of course, it is a bit difficult to set up, but if you save setting up pieces it is far easier next time.


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## RJM (Apr 11, 2010)

Here's a website I found very useful for setting up lock miter bits:

"Locking Miter Joint - a sure method to setting up."                            Page 1


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## allbarknobite (Sep 15, 2011)

*Using a lock miter bit on long boards*



derek willis said:


> Mark,
> Why are you locking such long boards, just curious.
> I used to use this bit extensively for the joining of cabinet sides together with no visible joint at all and have always been very pleased with the result, of course, it is a bit difficult to set up, but if you save setting up pieces it is far easier next time.


Derek, 
Thanks for the reply.

I am building a standup computer desk for laptop use, and I started out with 8' really straight boards.
Then I only had to rout 4 boards once to get get all 4 legs of the stand.

Setting up the lock miter was interesting, but the results were very good.
I did this on a modified RBI Hawk router table, which allowed me to stage cuts by turning a dial.

Thanks for looking.
Mark


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## harrysin (Jan 15, 2007)

I have to agree with Derek, there is no way that I would use a lock mitre for long boards, I normally use biscuits or on the odd occasion I've routed a slot all the way along and glued in a strip of thin plywood. I've made many trinket and jewellery boxes using the lock mitre, and the secret here is to keep a successful test piece every time you set up for a different thickness wood, this makes the next set-up so much faster. Here is one example where I used the lock mitre.


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## bobj3 (Jan 17, 2006)

Hi

I need to disagree with Harry and Derek, once the bit is setup right a 8ft board is Not a big deal..works great on the nasty plywood stuff.


http://www.binkyswoodworking.com/DrawerLockMiter.php
===



harrysin said:


> I have to agree with Derek, there is no way that I would use a lock mitre for long boards, I normally use biscuits or on the odd occasion I've routed a slot all the way along and glued in a strip of thin plywood. I've made many trinket and jewellery boxes using the lock mitre, and the secret here is to keep a successful test piece every time you set up for a different thickness wood, this makes the next set-up so much faster. Here is one example where I used the lock mitre.


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## allbarknobite (Sep 15, 2011)

*slots and plywood strips*



harrysin said:


> I normally use biscuits or on the odd occasion I've routed a slot all the way along and glued in a strip of thin plywood.


Hi Harry,
I just finished another router box built like an apron for a table. As you stated, I also used the technique that you prefer, to rout the required slots, and used 5/32" plywood strips, and wood glue to build the box. As if that wasn't enough, I added a metal leg bracket to each inside corner (6" down) to make the box completely rigid.

I accumulated several Lock-Miter _(Lock-Mitre) _bits from different manufacturers, and each requires it's own setup block. (They don't seem to be interchangeable.). I certainly could have used a different joint method, but using the lock miter bit was more of a challenge.

As ever,
Mark


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## harrysin (Jan 15, 2007)

The reason that I wouldn't use a lock mitre for long boards is that the wood has to be PERFECTLY flat or they will struggle to mate. As a matter of interest, wood bought from our BUNNINGS stores wouldn't stand a chance of fitting together would it James?


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## allbarknobite (Sep 15, 2011)

*Straight boards - Router Ready*



allbarknobite said:


> I started out with 8' really straight boards.
> Mark


Hi Harry, 
I had to sort through a lot of wood at our local Home Depot to find 5 suitable boards.(1 for setup) 
Most of the wood that I buy, warps a little, (the minute I bring it home) and is definitely not router ready. Even some of the kiln-dry wood.

I guess it's like bowling... you're first game is usually the best score for most beginners.
Mark


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## Gene Howe (Jul 10, 2007)

I've never attempted it, but wouldn't a lock miter be a good bit to use to make a leg with face grain on all four sides? 
I'll agree that they can be a b**** to set up.


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## derek willis (Jan 21, 2009)

harrysin said:


> The reason that I wouldn't use a lock mitre for long boards is that the wood has to be PERFECTLY flat or they will struggle to mate. As a matter of interest, wood bought from our BUNNINGS stores wouldn't stand a chance of fitting together would it James?


I am with you here friend, but then I have never bought prapared timber from a woodstore, and you do need a planer thicknesser if you are going to have timber of the right dimension and to have it straight, one question I need to ask, were these long lengths to be used as corners or joined on the straight?


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## derek willis (Jan 21, 2009)

Gene Howe said:


> I've never attempted it, but wouldn't a lock miter be a good bit to use to make a leg with face grain on all four sides?
> I'll agree that they can be a b**** to set up.


Gene, a very good idea, I see no reason why one should not do this, dimensions should be accurate and joining no bother, but, why!!!!!!
whwn you already have face grain on all sides.


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## Gene Howe (Jul 10, 2007)

derek willis said:


> Gene, a very good idea, I see no reason why one should not do this, dimensions should be accurate and joining no bother, but, why!!!!!!
> whwn you already have face grain on all sides.


Derek, thanks, I have so few good ideas.:sad:
A true 8/4 by 8/4 stick, to be a leg, would have face grain on two sides and edge grain on two, right? 
Four pieces of 3/4, joined with a 45 bevel on both sides (lock miter or not) would show face grain on all four sides. 
This past summer, in Amish country in the midwest USA, I saw a floor lamp built this way. The power cord ran through the center hole. So, I guess it wasn't my idea after all.:cray:


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## Dal300 (Jul 14, 2011)

I just did a Google search on "Lock Miter" and came up with some interesting columns, some about 4' long, some that were 12' long.

I've thought about doing them before, but have held off buying the bits because of need and cash.

One interesting item I saw was a 22 1/2° lock miter set that would be great for making some columns in an old house we have been looking at to purchase.


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## allbarknobite (Sep 15, 2011)

*Looks just like a long straight routed corner joint*



derek willis said:


> I am with you here friend, but then I have never bought prapared timber from a woodstore, and you do need a planer thicknesser if you are going to have timber of the right dimension and to have it straight, one question I need to ask, were these long lengths to be used as corners or joined on the straight?


Derek,

They stock was routed on the straight, and will form the 4 corners of the desk. 
Each of the 4 mitered legs is about 3"x3"x40". 
From the top, it looks just like a corner joint.
So I guess the answer is yes to both of your queries.
_(I did not do any cross-grain work, where I would then have to use a backing board and a sled.)_

Mark


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## jw2170 (Jan 24, 2008)

harrysin said:


> The reason that I wouldn't use a lock mitre for long boards is that the wood has to be PERFECTLY flat or they will struggle to mate. As a matter of interest, wood bought from our BUNNINGS stores wouldn't stand a chance of fitting together would it James?


I agree, Harry.

For lengths that long, I would look at Bob and Rick's rebate lock joint? If the outside surfaces are flush, the inside does not have to be critical,


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## derek willis (Jan 21, 2009)

Gene Howe said:


> Derek, thanks, I have so few good ideas.:sad:
> A true 8/4 by 8/4 stick, to be a leg, would have face grain on two sides and edge grain on two, right?
> Four pieces of 3/4, joined with a 45 bevel on both sides (lock miter or not) would show face grain on all four sides.
> This past summer, in Amish country in the midwest USA, I saw a floor lamp built this way. The power cord ran through the center hole. So, I guess it wasn't my idea after all.:cray:


Gene,
A piece of timber comes form a tree that is round, so all four sides are the same, attached.
001.jpg (227.9 KB)
002.jpg (151.6 KB)
003.jpg (140.8 KB)
004.jpg (158.6 KB)


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## Gene Howe (Jul 10, 2007)

Derek,
I see your point. That's a nice timber. Looks like what I call "rift cut". (growth rings 60 to 30 degrees from the face)
Unfortunately, the economics of milling (in the US, anyway) dictate that not all cuts from the log will be rift cuts. Most cuts are through and through the log. Resulting in some rift, some qtr sawn, some flat sawn etc. One can tell from each new stack which mill had regard for appearance and which simply started at one side of the log and kept cutting through to the opposite side. 
My sources of hardwood lumber allow me to pick my boards and timbers and often, I cannot find any whose rift grain is as nice as you've shown on all four sides. Of course, If the lumber is wide enough, one can always rip out the straightest grain for a solid 8/4X8/4 piece with nice straight grain on all four sides. Not always possible, though. And expensive, unless you can use all the off cuts. Hence the need to "wrap" the timber to achieve what nature and the millers haven't given us.


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## harrysin (Jan 15, 2007)

derek willis said:


> I am with you here friend, but then I have never bought prapared timber from a woodstore, and you do need a planer thicknesser if you are going to have timber of the right dimension and to have it straight, one question I need to ask, were these long lengths to be used as corners or joined on the straight?


I'm certain Derek that I don't really have to point out that if you put a banana through a thicknesser, out will come a slightly thinner banana! If all the pieces have to be passed a few times over the jointer before the thicknesser, then there will not only be a great deal of waste but a lot of time will be expended. Why therefore not just use biscuits or full length splines in the first place!


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## derek willis (Jan 21, 2009)

harrysin said:


> I'm certain Derek that I don't really have to point out that if you put a banana through a thicknesser, out will come a slightly thinner banana! If all the pieces have to be passed a few times over the jointer before the thicknesser, then there will not only be a great deal of waste but a lot of time will be expended. Why therefore not just use biscuits or full length splines in the first place!


All too true, I most certainly would not use a lock mitre for joining boards side to side, only corner to corner, quite so, bscuits or splines, I have a finger jointer that I use in some cases and I love the results especially when joining end on.


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