How to make this miter interlock cut?

mgdesigns · Post by **mgdesigns** » Fri May 25, 2012 1:28 pm

When I was a young man, I worked for a major store fixture manufacturer in Detroit, and they had an interlocking miter corner cut that I'd like to figure out how to make. They used 3/4" birch plywood for all cabinets, and the corner looked like this:

[ATTACH]17448[/ATTACH]
Suggestions and tips will be helpful.

Thanks.

pennview · Post by **pennview** » Fri May 25, 2012 1:44 pm

They are made with a router bit -- corner lock router bit -- (or shaper cutter). Here's an example from Woodcraft -- http://www.woodcraft.com/product/208237 ... 78-cl.aspx

reible · Post by **reible** » Fri May 25, 2012 7:52 pm

Hi,

If you get this router bit see if they have the set-up guide for it. I have one from some years back before they offered those and it is tricky get right the settings right first time.

This is a bit that you have to work with to get the setup right, there is one and only one set up that works. You have to have the height set and the fence depth set so the bit cuts both cuts from that one setting. You also make full depth cuts so it is not one you sneak up on, it is either right or it is wrong.

It is an interesting joint and if you decide to give it a go please report back with some results.

Ed

easterngray · Post by **easterngray** » Fri May 25, 2012 10:18 pm

The current special issue magazine by Woodsmith called ULTIMATE ROUTER HANDBOOK has an article on lock miter bits and how to set them up. Alec

charlese · Post by **charlese** » Sat May 26, 2012 1:35 am

For what it's worth, I make a similar drawer joint frequently. It is similar,but has no miter. It shows the front in it's entirety with only 1/4' end grain showing on the sides. This joint can easily be made with either a router or a dado blade.

[ATTACH]17460[/ATTACH]

holsgo · Post by **holsgo** » Sat May 26, 2012 7:42 am

I have this bit set and yes. You get one shot at being right with it. I only would use it for a few cases. I prefer hand cutting a dovetail. Try it with a coping saw. Once you get it right you'll always use it. Get good at it and they are fast, strong and require no power tool setup and tear down. But use a coping saw. You don't need all of those different saws that are sold.

nuhobby · Post by **nuhobby** » Sun May 27, 2012 2:52 pm

holsgo wrote:I have this bit set and yes. You get one shot at being right with it. I only would use it for a few cases. I prefer hand cutting a dovetail. Try it with a coping saw. Once you get it right you'll always use it. Get good at it and they are fast, strong and require no power tool setup and tear down. But use a coping saw. You don't need all of those different saws that are sold.

Interesting! Could you perhaps start a thread on this? I recently got a British Eclipse high-tension coping saw. Thinking of some hand-cut joints. Do you have a rule of thumb for teeth-per-inch?

JPG · Post by **JPG** » Sun May 27, 2012 11:22 pm

reible wrote:Hi,

If you get this router bit see if they have the set-up guide for it. I have one from some years back before they offered those and it is tricky get right the settings right first time.

This is a bit that you have to work with to get the setup right, there is one and only one set up that works. You have to have the height set and the fence depth set so the bit cuts both cuts from that one setting. You also make full depth cuts so it is not one you sneak up on, it is either right or it is wrong.

It is an interesting joint and if you decide to give it a go please report back with some results.

Ed

I will hazard a guess on a setup method. I am assuming the original post is accurate in that the miter angle shown is indeed a 45 degree angle.

[ATTACH]17475[/ATTACH]

The arrow points to a point(close) that should fall on the miter line and that edge of the 'tongue(s)'. It is in the center of the work piece thickness and an equal distance from the end(s)

holsgo · Post by **holsgo** » Mon May 28, 2012 7:35 am

Nuhobby...I'll do up something this morn.

mgdesigns · Post by **mgdesigns** » Sun Jun 03, 2012 6:47 pm

Sorry for the delayed reply - I was visiting my Dad in FL who will turn 90 on the 25th of June.

The joint is probably drawn a bit wrong - should have been 1/8" - 1/4" - 1/4" - 1/8" for 3/4" plywood or solids. But the tongues are squared as shown, not mitered ends. The purpose was to have a finished edge always. No room for errors though.
[ATTACH]17540[/ATTACH]