# Lock Mitre Cutter



## Sally Lunn (Jan 26, 2012)

I decided to have a change from using biscuits to join boards for a table top and purchased a Tornado TR244 Lock Mitre Cutter, which was described as " can also be used as a glue joint cutter when joining boards for a table top"
I thought it was a good buy as one cutter did two jobs.
However, it turned out to be a disaster. Setting up was quite dificult and used up a lot of "scrap" wood, but eventually I managed to get too boards level, as the first cut is done face side up, and the second face side down.
Using the first two of my prepared boards of 19mm oak I got a good clean glue joint by using 4 passes to obtain full depth. I must have been very lucky because from then on it was a gamble if the wood did not splinter. The cutter is designed to cut to a feather edge and on a few boards at it reached the end the knife edge it was cutting simply flew off, depending on the grain. This may have been acceptable if all the torn edges were underneath, but that is not possible.
I would love to hear from anyone else has used this cutter for jointing, because quite honestly I would chuck it in the bin.


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## paduke (Mar 28, 2010)

Stuart,

Its a great bit and aggravating RJM posted these links and since viewing them a deck of cards is a stable in my shop check out all three links. the begining deals with reversible glue joint then moves to lock miter. 

Router Table SOP —"Setting Router Bit Height on Work-in Turn Bits" ** Page 1

Router Table SOP —"Setting Router Bit Height on Work-in Turn Bits" ** Page 2

Router Table SOP —"Setting Router Bit Height on Work-in Turn Bits" ** Page 3


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## paduke (Mar 28, 2010)

well the links did not cut and paste so here is the thread http://www.routerforums.com/router-bits-types-usage/32830-45-degree-locking-miter.html
look for RJM60's post


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## CharleyL (Feb 28, 2009)

Sally,

Welcome to routerforums. 

These bits can be very tricky to get set correctly, as you have discovered. One of the things that must be done to achieve any success with them is to use stock that is exactly the same thickness, or you will have problems at the feathered edge. 
I've had problems using these bits too. Chip out is difficult to control, but can be minimized if you use a slow feed and follow the part with a sacrificial push block. You may also need to slow the bit speed to minimize burning. Stock with wild grain patterns can have all kinds of chip out, so make spare parts or try to pick your stock more carefully. 

A setup jig is available for Freud and Sommerfeld bits to allow quick setup of the bit height, but these may not work with other brands of bits, since the profile of the bit must be exactly the same as their bits for these to work. I have both brands of router bits and I had to buy both jigs to set them up correctly, even though these jigs and bits appear to be identical except for their color (mustard yellow and red). The bit profiles are slightly different between brands. After you succeed in getting the bit height correct, you then need to get the fence in exactly the right place. Only trial and repeated fine adjustments with scrap of exactly the same thickness as your parts will get this right, but once you have everything set it will make some beautiful joints.

Charley


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## Sally Lunn (Jan 26, 2012)

Followed your thread and looked at the photos. The jointing photo shows the cut across the grain, which is obviously much stronger, but try cutting with the grain. It's much easier for the sharp edge to fly off.


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## paduke (Mar 28, 2010)

I use the lock miter when making corners for cabinets with exposed end panels. I usually cut them to length after milling the lock miter. If you are doing a with the grain cut and you are getting a chip out on the end, could it be that the board is slightly rocking up as the board hangs over the table edge?

To avoid blowout at the end of a board You should use a sacricial block Also if not using a sled, the back corner on an end grain cut has a tendency to slightly dip into the bit cavity on your fence and cause a chip out


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## KenBee (Jan 1, 2011)

I also had a problem with my Lock Miter bit set-up so I ordered a UHMW set-up block from MCLS and now it is much easier. Even with the block it is advisable to test it with scrap first.

MLCS Lock Mitre Router Bits (At Bottom Of Page)


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## jlord (Nov 16, 2009)

Sally Lunn said:


> Followed your thread and looked at the photos. The jointing photo shows the cut across the grain, which is obviously much stronger, but try cutting with the grain. It's much easier for the sharp edge to fly off.


Gluing a joint along the grain will actually yield a stronger joint then gluing end grain to end grain.


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## Sally Lunn (Jan 26, 2012)

To Paduke.
Cutting with the grain causes splinters to fly off anywhere along the length due to a razor sharp edge it is trying to produce. It is impossible to use a sacrificial block half way down a board.
However I have now ordered a Tornado Reversible Glue joint cutter part no TR243.
This does not cut ant razor edges.


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## paduke (Mar 28, 2010)

Wow I use a MLCS bit on poplar oak ash and maple and not had splintering along the point. Is the 45 degree portion equal top and bottom? Is the edge snagging on the fence after leaving the bit?


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## Sally Lunn (Jan 26, 2012)

Paduke. Please confirm that you are using the cutter to join planks, i.e. for a table top.
Stuart


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## paduke (Mar 28, 2010)

No i use it to make outside corners on cabinets which requires with the grain cuts. this requires running one board vertically on edge and one board horizontally. Horizontally is the way material is fed to use the lock mitre as a bit to join planks. I use festherboards top and side because any wobble of material will cause splintering or diviting the sharp edge.
I also have developed a fetish for a flat top due to my use of this bit. 
This bit has caused sleepless nights
Caused me to design a sliding table for my fence 
http://www.routerforums.com/table-m...able-equals-horizontal-router.html#post238539

So keep trying I know how frustrating it can be


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