Woodworking Talk banner

1 - 8 of 8 Posts

·
rmorgan66
Joined
·
5 Posts
Discussion Starter #1
I am looking at buying a 45 Degree Lock Miter bit for a podium that I am going to build. After looking at the different size lock bits, I want to make sure that I get the right size. My question is this, Rockler is offering different size lock miter bits but I don't know which one I need. For example; 1 3/4 ---- 3/4 --- 1/2 so on and so forth. They have 6 diff sizes, so, how do I determine what size do I need for my router? FYI, I have a sears plunge router:blink:
 

·
Registered
Joined
·
620 Posts
The height of the bit needs to be slightly taller than the workpiece.

I'd recommend the bits from Eagle, and the matching setup blocks, if you're using 3/4 stock, they make the setup lots easier. If your stock is another thickness, that you will use again, make your own setup blocks from scrap and keep them.

That said: It really isn't that hard to set them up. The ones I have came with instructions and with careful adjustment it only takes a few tries to get the bit height set.
 

·
Registered
Joined
·
3,391 Posts
You buy the bit that matches the thickness of the wood you are planning to use. Usually they have a range of wood thicknesses that they will work with. ex. the 3/4 bit will handle both 1/2" and 3/4" thicknesses.

mdntrdr is right about those bits having a steep learning curve. I bought one to try and spent more than a few hours trying to use it properly. I ended up making a sled for my router table. That said, I felt that the effort was worth while and the bit was worth the money spent. I will use the bit on future projects.

If you are planning to join only the long grain edges together then using the bit is a snap. Align it to the proper height and depth. Then make multiple passes to cut the joint laying one board flat on the table and the other on edge. No sleds or other mods needed. If you will be joining end grain, then you will need a sled and backer boards to prevent tear out.

Careful set up is key to success, just like any other thing in this wood working game we all love..

Do the set up right, use a sled for end grain cuts, and you can get good results.

 

·
Old Methane Gas Cloud
Joined
·
3,500 Posts
As everyone has emphasized, setup is a female dog.

The one that is 1-1/16" in cutting length is probably your best choice for 3/4" stock. For anything less than 3/4" stock use the smaller bit with the 3/4" cutting height.

Any lock miter bit rarely uses the extremities of the cutting surface.

As far as set up goes . . .

Page 131 or so of the book, "In The Craftsman Style" has the best explanation of how to set up the bit.

In the Craftsman Style (In The Style): Fine Woodworking, Tim Schreiner: 0094115583985: Amazon.com: Books


Don't hold me to the exact page number but it is close. (I'm doing this from memory and I haven't seen the bock in about 5 years.)

The bad news is, "You'll never get the cut exactly perfect." You can get it close and then sand the joint.

As for reality and making legs, simple miters are just as good. You don't really need the extra gluing surface. Use blue tape to align the legs and then clamp. It works exceptionally well and the results are strong legs.

If you are making drawer boxes using Baltic Birch, a simple rabbet or locking rabbet works very well. With the simple rabbet, a trapped bottom can be made without the dado showing. With the locking rabbet and finesse, the same result is possible.
 

·
Wood Mangler
Joined
·
139 Posts
There is a tool called the Groove Center that helps set up a lock miter. I think Prazi USA makes it. It helps offset the fence and determine the height based on the actual thickness of the wood rather than trial and error. Has anyone used this? I was thinking of getting one (it also helps offset router fences to place a centered groove in one pass rather than 2) and was wondering if anyone had any experience.
 

·
Registered
Joined
·
291 Posts
If you understand the geometry, you can quickly set the bit up. I set all my bits at eye level; even have a rolling mechanics chair for that purpose. There are some bits that I will not use w/o a ZCI fence, and this is one of them. After you have a slap-on ZCI, set the bit so that the middle of the profile is centered on the horizontal workpiece and the the bit just MEETS the near vertical edge of the workpiece. IOW, you don't want to remove the point that's against the table. Here's some pics:





 
1 - 8 of 8 Posts
Top