Using Lock Miter Corner and Coping Sleds

[Anthony Whitesell]

I see how the coping sleds are supposed to work but until now I haven't tried to use one. I was trying to setup the lock miter corner bit on my router table and was having some difficulty holding the board against a simple square backer board so I whipped up a coping sled. I raised the bit to allow the sled to pass underneath. When I attempt to make the cut, the sled hit the router bit shank. Thinking this issue was specific to this bit, I looked at a few other bits that one might use a sled on and they all appear to have the same issue.

What am I overlooking here? :confused:

[Anthony Whitesell]

I think if you hit the shank, you went too deep with your fence. I would bring the fence closer to you. ( assuming your standing in front of the table) Clifford.

But then I can't use the bits full cutting height. I lose the center 1/4" (on the radius).

[Larry Edgerton]

You are going to have to ditch the sled. Same thing happens on the shaper occasionally. You don't have any choice with that cutter as the machined face is making 100% contact with the cutter.

Tip: Figure out what part of the cut can be done on the tablesaw or with a chamfer cutter and do that first.

[Anthony Whitesell]

Larry: You have hit the problem on the head with the lock miter bit. What bits or bit types do you or can you use the sled with?

I did figure out a way to use a "sled" for the cuts. I took a piece of 1/2" MDF and glued a 1/4" backer/stop to it. I put it on top of the work piece stop side down. I had a straight edge and a push block all in one.

[Larry Edgerton]

I use sleds on the shaper for small parts that are not safe otherwise such as chamfered rosettes and raised panel drawer fronts. I don't use them often as I have power feed on my shapers, but there are times when the work calls for them.

Another trick to keep it from falling on the last three inches is to hotmelt glue a piece of scrap on the back a little longer so that it never "Falls off the fence". Don't push on the hot melt too hard though, it is just a gentle guide. Most times I just make them 3" longer than need be and cut the ends off but there are times when stock is precious.

[Steve Leverich]

For just that reason, I bought one of these

http://www.infinitytools.com/prodinfo.asp?number=COP-100

Then built a bigger version for a project that was too large for it - you'd probably need to build a taller auxiliary fence for your table, making the upper part of the fence one-piece for the plexi runner to guide on - that's what I did.

I have a couple of the Freud really tall architectural molding bits so I needed to cut a tall "mouse hole" in the aux fence to clear them - but this sled concept is vastly superior to the "normal" ones IMO.

Hope this helps... Steve

[glenn bradley]

This is one reason I have my coping sled (http://www.sawmillcreek.org/attachment.php?attachmentid=43928&d=1154660566)ride in the miter slot. This frees the sled (http://www.sawmillcreek.org/attachment.php?attachmentid=43930&d=1154660657) from relying on the fence and allows the base of the sled to be positioned away (http://www.sawmillcreek.org/attachment.php?attachmentid=43929&d=1154660575) from the bit.

[Anthony Whitesell]

I have that option as well, but it doesn't work well with the lock miter and corner lock bits.

[Anthony Whitesell]

My fence is 6" tall :D for support vertical routing, but the panels are 14-18" wide. :eek:

[glenn bradley]

I have that option as well, but it doesn't work well with the lock miter and corner lock bits.
I use mine for drawer-lock bits all the time. I was planning on getting a lock-miter and just assumed I would use it the same way as they are both single-bit interlocking profiles. What should I watch out for?

[David DeCristoforo]

This falls under the heading of "special tooling". To me the literal interpretation of "special tooling" is "anything that you can't use your regular stuff for". How's that for a bunch of technical jargon? Bottom line is you need to make another sled that will work with this cutter. And don't get too tired of doing this because this will not be the last time you find that you need to get out of the box. After you have been working in your shop for a while, you will probably have lots of sleds as well as many other strange looking objects that you can clearly remember making but with absolutely no recollection of exactly what they were for....

[Anthony Whitesell]

I have found that there are two drawer lock profiles or designs. A corner drawer lock bit (http://www.rockler.com/product.cfm?Offerings_ID=5709&TabSelect=Details) which is 1 1/2 to 2" in diameter and a drawer lock bit (http://www.rockler.com/product.cfm?Offerings_ID=2140&TabSelect=Details) that is only 1" in diameter. (Now that I look again, it seems that they are both called just drawer lock bits)

The issue is that the full profile of the bits (lock miter, glue joint, ogee, etc.) encompasses the center 1/2" diameter (1/4" radius) of the bit and can't cut the full profile if you use a sled.

Specific to my attempt was that the bit is specified to cut stock up to 3/4" thick, but the point of the bit was within the center 1/4" radius and therefore in deeper than the shank of the bit. So using a typical sled won't work to reach the full height.

I believe that if you attempt to do a 1/2" recessed side with your drawer lock bit, you'll encounter the same problem.

[Ryan Baker]

I never found much use for the sleds that ride along the fence for just these sort of reasons. Just use a waste backer block behind the real piece (to prevent tear-out and support the piece), attach it to a miter gauge and use that to feed the stock through. It works every time.

[Steve Bishop]

I also attached a backer board the piece being mitered with double sided tape. Found there was no edge left on the board to guide it once passed the bit. The backer board kept the piece square against the table or fence while routing.

http://i245.photobucket.com/albums/gg57/techie470/IMAGE_093.jpg

http://i245.photobucket.com/albums/gg57/techie470/IMAGE_094.jpg

For checking the set up of the bit, take two mitered boards and mate them together, one face up the other face down. This will show if your height or depth is off.

http://i245.photobucket.com/albums/gg57/techie470/IMAGE_099.jpg

http://i245.photobucket.com/albums/gg57/techie470/IMAGE_098.jpg

I can't claim these ideas as mine, found them at various bit manufactures web sites. Also if your using plywood score the cut line before taking it to the router table, this will help minimize tearout.


Hope this helps.
Steve