Drawer lock bit

[Steven Bolton]

Does anyone have experience using a drawer lock bit like this one?

I guess I would like to know how strong a joint it creates and how much fuss there is to set it up.

thanks

Steve Bolton

[Peter Quinn]

I have one. The joints are strong for reasonable sized drawers. Set up takes a few test cuts and very accurately milled stock. Can be a bit fussy until you have set up blocks established.

I did my typical 'glue up a sample then smash it with a big hammer' test on some oak. This joint doesn't give up easy and offers some resistance to the pulling force exerted on a drawer but otherwise little inherent mechanical strength. As long as the glue lasts the drawer will last.

Very quick when making a lot of drawers.

[Peter Quinn]

Oh, I have a Hitchcock side table which has two maple drawers made using this same type of cutter. The table must be 45+ years old (inherited from grampa) and the drawers are solid. Have never tried smashing these with a hammer though!

[Jack Gingerich]

I've used it on several projects and am quite satisified with results. As has been mentioned, there is some set up and testing required.........but don't most? The nice thing is you make both cuts with same cutter, just rotate the workpiece 90 degrees and change height of the bit. Jack

[Brian W Evans]

I just got an Infinity Tools catalog today and they sell a bit like this that comes with free setup blocks.


http://www.infinitytools.com/PDF/CAT11CW15_FINAL.pdf

Page 4 of the catalog - page 6 of the PDF.

[Vernon Taylor]

Instructions - #55-512 Drawer Lock Joint Bit
SAFETY
The Drawer Lock Joint Bit is designed for use with a table-mounted router only, at a maximum of 18,000 rpm.
The Infinity Drawer Lock Joint Bit makes very strong joints that can be used in many applications besides making drawers.
Always unplug the router before changing or working around the router bit.
Always use push sticks, featherboards and other appropriate safety devices to keep your hands a safe distance from the bit.
MATERIAL PREPARATION
Minimum material thicknesses for the Drawer Lock Joint Bit are ¾" for the drawer front and from ½" to ¾"-thick for the sides. When making a box-type drawer use the same thickness material for the rear face as used for the front.
The material must be flat and square with accurate 90-degree end cuts for the joints to be straight and the drawer flat.
BIT SETUP
Use test pieces of the same thickness as the material to be joined. When the setup is perfected, save the last test piece to be used as a setup gauge when joining the same thickness wood in the future.
Install the bit and set it to a height of 7/16" above the table surface. Once the bit height is confirmed by test cuts, it remains constant when cutting the fronts and sides.
FENCE SETTINGS
(Top) A piece of the side material with a straight board held against it makes an accurate gauge for setting the fence for the front panel cut. (Bottom) Use a thin straight edge to get the straight part of the cutter flush with the fence.
Drawer Front – For flush joints, the bit exposure outside of the fence is equal to the thickness of the side stock. An easy way to set this is to place a piece of drawer side material flat against the fence and then hold a longer straight piece of wood against that, extending across the cutter. Adjust the fence so that the tip of the cutter can rotate and just clear the long piece of wood.
With ½"-thick side stock, setting bit exposure to ¾" will leave a ¼" overlap at each end of the drawer front.
Drawer Sides - For the sides, bit exposure is set so that the vertical straight portion of the cutter is flush with the fence.
CUTTING ORIENTATION
The drawer front is machined outside face up, flat on the table. Because the bit is usually cutting directly across the grain, a backer board is necessary to prevent grain blow out as the bit exits the wood.
The side pieces are machined vertically, their inside faces against the fence and cutter.
Remember that bit height remains the same when cutting the fronts and sides, only the fence position changes. When the drawer sides are being made from sheet material it is easier and safer to machine the groove in the sheet and then cut the side pieces from it.
ADJUSTING JOINT FIT
Make a test joint and hold the pieces together. If the joint is loose, raise the bit slightly. If the joint is tight, lower the bit slightly. To correct a loose joint use the gap between the inner edge of the side where it meets the drawer front as a gauge. Because the correction is applied to both the drawer front and sides, adjust bit height by ½ of that gap width. Cut a new test joint (drawer front and side) and check the fit to confirm the fit is correct.
ASSEMBLING THE JOINT
Being precise when setting the initial 7/16” bit height will speed the setup process.
Dry fit the pieces to be sure the joints fit properly and close snugly. Apply glue to the contact surfaces and assemble the drawer, inserting the bottom panel in the process. Place in clamps and apply just enough pressure to draw the joints closed. Because of the large amount of glue surface, mechanical fasteners are not required though can be added if you wish.
Measure the diagonals across the drawer to be sure it is square before setting aside to dry.
Sand the joints smooth before applying finish or sealer.
DRAWER LOCK JOINT BIT USES
Your Infinity Drawer Lock Joint Bit has uses beyond drawers. This joint is very strong and works well for making boxes, cabinets and virtually any project where pieces join at a 90-degree angle.
CLEANING AND MAINTENANCE
For the best performance, keep your Infinity Drawer Lock Joint Bit clean. Built up pitch and sap can insulate the bit, causing it to run hot. The excessive heat can damage the cutting edge.
DO NOT use caustic materials like oven cleaners as they can damage the bond between the carbide cutters and the bit body. Most woodworking supply outlets have commercially prepared solutions that safely remove the pitch and gum associated with machining wood. There are also several household cleaners that are effective in the cleaning of router bits.
For more on using the Drawer Lock Joint Bit see the "Instructions" section of www.infinitytools.com. The peceeding is from Infinitys Site, I have used this and found the results were good as prevuiusly stated produced good results though a little fussy to set up.

[J. Z. Guest]

Steven: I considered this type of bit for a good while.

Take a look at this page, about 1/3 of the way down. MLCS has two drawer lock bits, and a nice set-up video too. (I like their bits too, BTW)

It seems to me to be a hell of a lot of set-up for such a simple joint. It seems like the main strength is that once it is set up, you can really crank them out.

There's a glue joint bit further down the page that can also be used as a drawer lock bit, and double as a glue joint maker.

In the end, I wound up going with the Pins and Tails through dovetail jig. My wife & I are both suckers for through dovetails. I figure if I'm going to have to spend time setting up anyway, may as well have some great eye candy when you're through. The $50 price is great too. There's also a video for that one.

[Steven Bolton]

Jeremy:

You give a very strong argument for dovetails. I think that is the way to go. But does it look funny with Baltic birch I wonder.

Steve Bolton

[Michael Ward]

Jeremy,

I have the MCLS lock joint bit, which is a little different than the drawer lock bit you showed. I had 12 drawers to make from 1/2" ply, the largest of which was 10" deep X 18" Long X 12" wide. My issue was I could not get a clean joint with dovetails (a terrible mess with plywood, depending on the quality) and needed something stronger than a rabbet. In my opinion, once the setup is complete, these joints rock.....very strong and very easy to assemble. The pics are of my attempt with dovetails, the lock joint and the verticle setup with a special fence just for this purpose.

Best Regards,
Michael

[Eric DeSilva]

You might reduce the tearout on cutting DTs in ply with a backer board the router could run into...

I've been curious about the drawer lock bits, but my principle concern was holding strength in plywood. If you look at the middle "tongue" and the way it could match up with the wood plys, it just doesn't give me a lot of confidence that the load bearing part of the joint it really fixed to something strong...

[glenn bradley]

Does anyone have experience using a drawer lock bit like this one?

I guess I would like to know how strong a joint it creates and how much fuss there is to set it up.

thanks

Steve Bolton

That is my preferred method of making drawers. Unless there is an aesthetic reason not to, I will use this method. I have shop drawers, kitchen drawers and heavily loaded (canned goods) pantry pull-outs made with this joint (glue only). No failures.

Make a few practice runs and once you have a good fit, make a setup block, write the material, etc. on it with a felt pen and toss it in a box for next time. I have blocks with four different setups on four edges for four different materials (conserves space).

[J. Z. Guest]

That's a good point about the plywood Michael, one I hadn't considered.

From what I can see in the last pic, it looks like a lock miter bit. Is it that or a drawer lock bit?

Looks like I may end up getting one of these too, in the long run. For now, my drawer sides & front will be solid wood, so I don't have to worry.